So this isn’t a post about how collagen is a scam and you got fooled. Collagen is a real protein, the most abundant one in your body as a matter of fact. And there are real placebo-controlled trials behind some of what these brands claim. This is a post about a narrower, more useful question: when you take away the industry funding, how much of the promise is left? And is the powder in the tub the thing that was actually studied?

There’s a longer story here about how brands cite research, and to their credit, some cite carefully. Vital Proteins’ education pages cite a muscle study for a muscle claim and an absorption study for an absorption claim, both used correctly. The overreach on those pages is smaller and sneakier: a sourced, hedged claim about muscle, followed immediately by an unsourced claim about athlete recovery and endurance, sitting right next to a product link. The study they cite is in elderly patients with sarcopenia, not athletes. When the sold claim is broader than the sourced one, that gap is the tell.

The short version: collagen lands at Oversold. It’s clean and safe, and actually gets absorbed into your blood stream. But the evidence is fragile. The brand copy headlines a skin benefit, which mostly disappears once you control for who paid for the studies and the better-supported joint benefit was tested on things other than the powder. Most importantly, the effective dose in these same studies is a fraction of the scoop you’re paying for. Let me show you the receipts.

The skin claim: real… in the studies funded by Big Collagen

Start with the marketing. Vital Proteins, the category’s biggest name, tells you flatly on its site: “Collagen peptides promotes skin elasticity and hydration.” That is the headline claim, the reason many people buy a tub.

And here is the honest part: there are real randomized, placebo-controlled trials that found exactly that. Proksch and colleagues (2013, Skin Pharmacology and Physiology) randomized 69 women to 2.5 g, 5 g, or placebo for eight weeks and found a statistically significant improvement in skin elasticity. Asserin and colleagues (2015, Journal of Cosmetic Dermatology) found significant improvements in skin hydration and dermal collagen density. A larger 2023 trial by Seong and colleagues found improvements in wrinkles, elasticity, and hydration. If you pool all the trials together, collagen looks like it works for aging skin.

Here is the catch, and it is the whole post. Every one of those trials is tied to a collagen manufacturer. Proksch’s author list includes scientists from a collagen ingredient company. Asserin’s includes an author from a collagen supplier. Seong’s tested a specific branded low-molecular-weight peptide, and its own acknowledgments state the peptides were prepared by a manufacturer two of the authors are affiliated with. None of that makes them fraudulent. Industry funds a lot of legitimate nutrition science. But it means the pooled “collagen works for skin” result is a result about manufacturer-run trials, and the honest question is whether the effect survives when you look only at the studies with no commercial stake.

Someone finally checked. In 2025, Myung and Park published a systematic review and meta-analysis in The American Journal of Medicine built specifically to answer this. It pooled 23 randomized controlled trials, 1,474 participants, and declared no funding and no conflicts of interest. Pooled across all 23 trials, collagen significantly improved skin hydration, elasticity, and wrinkles, the headline you would expect.

Then they split the trials by funding source. In the studies not funded by industry, there was no significant effect on hydration, elasticity, or wrinkles. When they split by study quality, the high-quality trials showed no significant effect either. The authors’ own conclusion, verbatim: “There is currently no clinical evidence to support the use of collagen supplements to prevent or treat skin aging.”

That is the funding collapse. The skin benefit, the reason the category exists, is real in the trials run by the companies that sell it and mostly disappears in the independent, high-quality ones. It is not that collagen was proven useless for skin. It is that the effect tracks the funding, and the marketing sells you the pooled number without the asterisk.

The joint claim: better evidence, wrong format

Here’s the strange part. The claim with the better evidence is the one the brands treat as a bonus.

Look at how Vital Proteins orders its own page. The “Why Collagen?” section opens entirely on skin: “As you age, your body’s natural collagen production may decline (think fine lines, wrinkles, decreased skin hydration & elasticity).” Then the support list runs “Skin, Hair & Nail Support” first, “Bone & Joint Support” second. In the benefits block it’s the same: “Supports healthy hair, skin, nails and joints,” with joints at the tail end. Skin is the reason-for-being; joints are the add-on.

But joints are where collagen’s independent evidence is genuinely stronger.

So why isn’t collagen a clear win for joints? Because of what got pooled. Liang’s “collagen derivatives” category blended three very different things: undenatured type-II collagen (a completely different molecule taken at about 40 milligrams), collagen injected directly into the joint, and oral hydrolyzed powder at 5 to 10 grams. The meta-analysis never isolated the hydrolyzed-powder-only result. So “collagen helps osteoarthritis” is true for the category in the broad sense, but it is not the same statement as “the hydrolyzed powder in your tub relieves your knee.” The best joint studies are testing a 40 mg pill or a needle, not the scoop.

There are individual trials of oral hydrolyzed powder for joints, and the effects are real but modest. One 200-person trial (Bruyère 2012) was significant at six months but not three; another 250-person trial (Benito-Ruiz 2009) found the effect concentrated in the most-affected subgroup. Both were industry-linked. Genuine evidence, just softer than the pooled headline, and still not about the powder specifically. And the dose given to participants was a mere fraction of the serving sold to you.

Now the part that costs you money. The skin trials that found an effect used about 2.5 to 5 grams a day. The hydrolyzed joint trials clustered around 10 grams. A typical collagen scoop is 20 grams. Vital Proteins’ powder serves 20 grams; Thorne’s scoops are in the teens; the marine and “prenatal” versions vary.

So even in the studies that worked, the effective dose was a fraction of what the tub tells you to take. You are paying for grams the evidence didn’t need. That matters because collagen is priced by the gram, and a bigger scoop is a bigger bill for no added proof.

While we’re on money, one more move worth naming. Vital Proteins sells a marine collagen at a premium over its bovine version. However on its own FAQ page, the company states plainly that “Marine collagen’s benefits are the same as the benefits of bovine collagen.” Same stated benefit, higher price. When a brand tells you in its own words that the pricier version does nothing extra, believe it. It’s an ethical upsell.

A brief word on botanicals

Some brands don’t rest the anti-aging claim on collagen at all. Thorne’s Collagen Plus attributes its wrinkle and skin-texture claims to added botanicals, a currant polyphenol blend called MitoHeal and a peach-derived ceramide, rather than to the collagen itself. That is worth knowing because it means the “reduce fine lines” promise on a collagen product is riding on ingredients that aren’t collagen. The botanical’s own human evidence is a single 40-person, one-month pilot study (Hooper 2022), and the product uses the lower of the two doses that pilot tested. It is not nothing, but it is thin, and it is doing work the collagen can’t.

The verdict: Oversold

Collagen is a real protein, the same one your body already makes and makes less of as you age, which is the true premise the whole category is built on. It is clean, it is safe, and you do absorb it. Those things are not in dispute.

What’s oversold is the certainty. The skin benefit, the headline, doesn’t survive independent, high-quality trials. The joint benefit, the stronger claim, wasn’t tested on the powder you’re buying. The effective dose is a fraction of the scoop, and the premium versions charge more for, by one brand’s own admission, the same thing.

If you want to try it anyway, and plenty of reasonable people will, here’s how to do it without overpaying for hype: buy plain hydrolyzed collagen peptides, take the studied dose (2.5 to 5 grams for skin, around 10 grams for joints, not the full 20 gram scoop), skip the marine premium and the botanical blends, and pick whichever plain tub is cheapest. Marine versus bovine is a price and preference call, not an evidence one. And credit where it’s due: these are genuinely clean, tested, often third-party-certified products. Just remember what that certification means. It certifies the powder is pure. It does not certify that it works.

Gift / Grift runs on evidence, not sponsorships, which means nobody's paying me to tell you a $0.68 tub beats a $1.83 one. If you'd like to keep it that way, you can buy me a coffee. It's what keeps this independent.

Buy me a coffee

Sources

Every figure in this piece was checked against the primary source. Verified references:

• Myung SK, Park Y. Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials. The American Journal of Medicine, 2025. DOI: 10.1016/j.amjmed.2025.04.034. (Independent; no funding, no conflicts. Effect present pooled, absent in non-industry and high-quality subgroups.)

• Liang CW, Cheng HY, Lee YH, Liao CD, Huang SW. Efficacy and safety of collagen derivatives for osteoarthritis: a trial sequential meta-analysis. Osteoarthritis and Cartilage, 2024. DOI: 10.1016/j.joca.2023.12.010. (Independent; no funding, no conflicts. Pools UC-II, injectable, and oral hydrolyzed collagen.)

• Proksch E, Segger D, Degwert J, Schunck M, Zague V, Oesser S. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacology and Physiology, 2013. DOI: 10.1159/000351376. PMID: 23949208. (Industry-affiliated authorship.)

• Asserin J, Lati E, Shioya T, Prawitt J. The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network. Journal of Cosmetic Dermatology, 2015. DOI: 10.1111/jocd.12174. (Industry-affiliated authorship.)

• Seong SH, et al. Low-molecular-weight collagen peptides supplement promotes a healthy skin: a randomized, double-blinded, placebo-controlled study. Journal of Cosmetic Dermatology, 2023. DOI: 10.1111/jocd.16026. (Declares no funding or conflicts; peptides prepared by a manufacturer two authors are affiliated with.)

• Bruyère O, Zegels B, Leonori L, Rabenda V, Janssen A, Bourges C, Reginster JY. Effect of collagen hydrolysate in articular pain: a 6-month randomized, double-blind, placebo-controlled study. Complementary Therapies in Medicine, 2012. DOI: 10.1016/j.ctim.2011.12.007. (n=200, 1.2 g/day; responder rate significant at 6 months, not at 3.)

• Benito-Ruiz P, Camacho-Zambrano MM, Carrillo-Arcentales JN, et al. A randomized controlled trial on the efficacy and safety of a food ingredient, collagen hydrolysate, for improving joint comfort. International Journal of Food Sciences and Nutrition, 2009. DOI: 10.1080/09637480802498820. (n=250, 10 g/day; benefit concentrated in the most-deteriorated subgroup.)

• Zdzieblik D, Oesser S, Baumstark MW, Gollhofer A, König D. Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial. British Journal of Nutrition, 2015. PMID: 26353786. PMCID: PMC4594048. (Muscle-mass trial; cited correctly by brands for a muscle claim.)

• Shaw G, Lee-Barthel A, Ross ML, Wang B, Baar K. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. The American Journal of Clinical Nutrition, 2017. DOI: 10.3945/ajcn.116.138594. PMID: 27852613. PMCID: PMC5183725. (Absorption/synthesis-marker study; cited correctly for an absorption claim.)

• Iwai K, Hasegawa T, Taguchi Y, et al. Identification of food-derived collagen peptides in human blood after oral ingestion of gelatin hydrolysates. Journal of Agricultural and Food Chemistry, 2005. DOI: 10.1021/jf050206p. PMID: 16076145. (Bioavailability.)

• Khatri M, Naughton RJ, Clifford T, Harper LD, Corr L. The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic review. 2021. PMID: 34491424. PMCID: PMC8521576. Amino Acids. (Muscle/recovery context.)

• Aussieker T, Hilkens L, Holwerda AM, et al. Collagen protein ingestion during recovery from exercise does not increase muscle connective protein synthesis rates. 2023. PMID: 37202878. PMCID: PMC10487367. Medicine & Science in Sports & Exercise. (Counterweight to muscle-synthesis framing.)

• Hooper S, Hausenblas HA, Winters C. Efficacy of MitoHeal supplementation on adult skin quality and patient satisfaction: a randomized, double-blind, placebo-controlled pilot study. Clinical and Experimental Dermatology, 2022. DOI: 10.1111/ced.15371. PMID: 35973827. PMCID: PMC10092201. (40-person, one-month botanical pilot; funded in part by the manufacturer.)

Brand pages (Vital Proteins, Thorne, Momentous, Needed, Ancient Nutrition) captured with URL and timestamp; pricing is one-time; archived copies on file.

A younger version of me would have bought it too. The pitch is genuinely convincing, and the ingredient underneath it isn’t fake. There is real science on apple cider vinegar. That is exactly what makes this one hard, and exactly why it is worth walking through carefully.

Because somewhere in the last few years, a kitchen staple got repackaged into capsules and gummies, given a Supplement Facts panel, and sold back to us as a wellness intervention at twice the price. And there is a real gap between what the science shows and what the bottle implies. Not a lie. A gap. The active ingredient in vinegar, acetic acid, is not nothing, it is just narrow, mostly studied in people with metabolic issues to begin with, and almost none of it survives the trip into a pill.

Let’s separate the ingredient from the marketing, and see which one keeps its promises.

What acetic acid actually does

The active compound in apple cider vinegar is acetic acid. When researchers study “ACV,” acetic acid is the thing doing whatever gets done. So the honest question isn’t “does apple cider vinegar work,” it’s “what has acetic acid been shown to do, in whom, at what dose, and in what form.” As with a lot of things in science, the answer is “it depends.” It depends on who it’s being tested in, at what dose, and in what form, and that’s exactly where the marketing oversells.

Blood sugar: real, but likely not for you. This is the strongest limb of the evidence, and it comes with the biggest asterisk. An eight-week randomized trial in adults with type 2 diabetes found that 30 mL (which contains about 1,500 mg of acetic acid) of ACV per day significantly lowered fasting blood glucose, along with improvements in HbA1c and LDL cholesterol (Jafarirad et al. 2023). A 2025 GRADE-assessed systematic review and dose-response meta-analysis of seven trials, again in people with type 2 diabetes, confirmed significant reductions in fasting blood sugar and HbA1c, and found the effect was dose-dependent (Arjmandfard et al. 2025). This is real evidence. It is also, almost entirely, evidence in people who have a blood-sugar problem to fix. A broader meta-analysis of acetic acid across mixed populations found the fasting-glucose effect showed up in diabetics and washed out when healthy and overweight people were pooled in (Valdes et al. 2021). A healthy adult does not have dysregulated blood sugar. There is very little here for them.

Triglycerides: the quiet, consistent win. Across trial after trial, the most reproducible effect of ACV isn’t weight or glucose, it’s a modest reduction in triglycerides (seen in Kondo 2009, Khezri 2018, Jafarirad 2023, and Valdes 2021). It is, notably, the benefit almost no brand puts on the front of the bottle, which is worth sitting with: the effect the evidence best supports is the one the marketing ignores, and the effects the marketing shouts about are the ones the evidence supports least.

Weight: small, fading, and contested. This is usually the headline claim, and it is the weakest of the “real” ones. Individual trials do show something. A 12-week double-blind study in obese adults found that daily vinegar (in two arms, 750 mg and 1500 mg of acetic acid) produced significant reductions in body weight, BMI, visceral fat, and triglycerides versus placebo (Kondo et al. 2009). A 2018 trial found ACV added modest benefit on top of a calorie-restricted diet (Khezri et al. 2018). But two things keep this firmly in the modest category for evidence. First, the pooled acetic acid meta-analysis found no significant effect on any anthropometric marker, including BMI (Valdes 2021), so individual trials show effects the broader picture doesn’t confirm. Second, the effects that do appear are small, tend to reverse when people stop taking ACV, and often ride alongside dieting rather than standing alone.

And then there is the trial that can no longer be looked at for evidence. In 2024, a study in BMJ Nutrition, Prevention & Health reported dramatic weight loss from ACV in Lebanese youth and received a lot of attention. In 2025 it was retracted, over concerns about the statistical analysis, implausible values, the reliability of the underlying data, inadequate reporting, and a lack of prospective registration. I need to be precice here: the paper was withdrawn for data-integrity and reporting problems. It was not “disproven.” But it can no longer be cited as support, and it was the single most-shared piece of “ACV melts fat” evidence on the internet.

Gut health: the loudest claim, and the emptiest. Here is the one they push hardest, and it is the one with essentially no human evidence behind it. I spent a good hour looking. I could not find a single human clinical trial showing that apple cider vinegar improves digestion or the gut microbiome. Neither, for what it’s worth, could the American Association of Naturopathic Medical Colleges, a body with every professional incentive to find a benefit, which states plainly that gut claims are where popular ACV lore most exceeds the evidence, and that support for ACV extrapolates from animal studies and isolated properties rather than human trials (AANMC, 2026).

The one study that comes closest is almost hilarious in how badly it fits the claim. It’s a mouse study on constipation, and its entire design is built around the fact that ordinary acetic acid, the kind you swallow, gets absorbed in the small intestine and never reaches the colon. The researchers had to chemically engineer a special starch to smuggle acetic acid down to the large intestine, precisely because oral acetic acid can’t get there on its own (Wang et al. 2020). Let me say that again: the closest thing to evidence for “ACV for gut health” is a study whose premise is that swallowed vinegar doesn’t reach your gut.

So that’s the landscape. A real, narrow benefit for blood sugar and triglycerides, concentrated in metabolically unwell people. A small, fading, contested effect on weight. And a gut-health claim with no human trial at all. Dozens of studies exist, but they cluster at the top of that list and thin out toward the bottom, exactly where the marketing gets loudest.

Now let’s look at how four different real brands sell it.

Four brands, four moves

I want to be fair. None of these products is a scam in the sense that matters, they are, as far as their labels and certifications show, clean, and often genuinely well-made. The problem isn’t safety or purity. The problem is the distance between what the evidence supports and what the marketing implies. Each of these four brands closes that distance a different way.

Bragg: the honest one that still oversells. Credit where it’s due, and Bragg earns some. Their ACV capsules do something most of the others in the category don’t: they disclose the actual acetic acid content, 750 mg per three-capsule serving. That is unusually transparent, and it lands right at the low end of the dose the trials used. Their marketing even tells you “3 capsules replace your daily tablespoon,” which is roughly accurate. The label is clean, no added sugar, with real added vitamin D and zinc (which is where their immune-boosting claims come from).

So where’s the catch? It’s in the outcome claims. The panel and page attach weight, blood glucose, cholesterol, and immune benefits to the product, each trailing an asterisk. Follow the asterisks and they all resolve to the same footer: “these statements have not been evaluated by the Food and Drug Administration.” That’s not a citation. That’s a legal disclaimer wearing the costume of one. And one line on their ingredient card makes a specific empirical claim, that “scientific research shows the amount of acetic acid in our supplements is linked to weight management, blood sugar control, and overall digestive health.” Held against the evidence, that sentence fails on all three counts: weight (no pooled effect), blood sugar (diabetics only), and digestion (never measured).

Trace Minerals: real citations, doing no work. This one is a blog post arguing that ACV is a “prebiotic” that “optimizes stomach acidity,” “stimulates digestive enzymes,” and “reduces bloating,” each stated as established fact. Underneath sits a list of five scientific references, which looks reassuring until you actually open them. Only one is about vinegar and the gut at all, and it’s preclinical (aka in mice, not in humans). Another is about manufacturing vinegar. One is about minerals and immunity, nothing to do with ACV, quietly propping up a mineral cross-sell. This is the difference between having a citation and having support. A reference list is not evidence if the references don’t say what the text claims. (Credit where due: Trace’s actual usage advice, dilute it, watch your tooth enamel, mind the interaction with insulin and diuretics, is responsible and correct. The problem is the mechanism claims, not the safety guidance.)

HUM: the brand that cited a real trial, for the wrong ingredient. HUM deserves the most credit of the four, because they did the thing almost no one does: they cited an actual randomized controlled trial. Their Pro ACV Gummies advertise that “98% achieved digestive regularity,” footnoted to a genuine, well-conducted study (Madempudi et al. 2020). Here’s the catch, and it’s a showstopper. That trial tested Bacillus coagulans, the probiotic strain in the gummy, at 2 billion CFU, in a standalone capsule. It has nothing to do with the apple cider vinegar. So the clinical proof point on an apple cider vinegar product is actually evidence for the probiotic along for the ride. (For the record, the “98%” figure specifically refers to stool consistency, not the “regularity” the marketing labels it.)

It gets sharper. HUM also cites, in support of its metabolic framing, a meta-analysis of ACV on lipids and glucose (Hadi et al. 2021). Open it, and buried in the results is a finding they presumably didn’t expect anyone to read: in apparently healthy participants, ACV appeared to increase fasting blood glucose, not lower it. HUM cited a paper whose own data argues against the benefit, in exactly the healthy population they sell to. That is what happens when you check a brand’s sources instead of trusting that a source exists.

Goli: four moves in one gummy. Goli, the “World’s First Apple Cider Vinegar Gummies,” is the richest single specimen, because it runs nearly every play at once. The gut claim is justified as tradition, not evidence: their page reads “Apple Cider Vinegar has been used for centuries as a traditional remedy for Digestion, Gut Health.” When a product reaches for “centuries” and “traditional remedy,” that’s the tell that there’s no trial, because if there were a trial, they’d cite the trial. On dose, they disclose “500 mg apple cider vinegar” per gummy and never once state the acetic acid content, which is the number that would actually matter, so you cannot know whether it reaches any studied dose (and 500 mg of vinegar solids is nowhere near the 750 to 1500 mg of acetic acid the trials used). There’s the sugar irony: at their recommended one-to-two gummies three times daily, you’re eating up to 12 grams of added sugar a day to chase a “metabolic” benefit. And like HUM, the actual health claims, energy, immunity, heart, “cellular energy”, are pinned to added vitamin B12, with the ACV out front taking credit for what the vitamin is doing.

Four brands. Honest disclosure that still oversells; real citations doing very little work; a real trial for the wrong ingredient; and tradition cosplaying as evidence. That’s not four scams. It’s four versions of the same gap between the vinegar and the marketing.

The catch underneath all of it: dose and form

Even if you set the marketing aside, two problems sit under the entire category.

The first is dose. The trials that showed a measurable effect used roughly 750 to 1500 mg of acetic acid, delivered as liquid. A typical capsule sits at the very bottom of that range, when it discloses the number at all, and many gummies don’t disclose acetic acid content whatsoever.

The second is form, and it’s the more damning one, because it’s not a limitation, it’s a finding. In a head-to-head trial, researchers compared liquid vinegar against vinegar tablets for blunting the post-meal blood sugar rise (Feise & Johnston 2020). The liquid worked, cutting the glucose spike by about 31%. The tablets? The whole tablets did nothing, matching the placebo, even though they contained more acetic acid than the liquid did. The failure wasn’t the dose. It was the delivery. A solid form that has to dissolve and release just didn’t perform the way the liquid did.

So the pill is fighting a two-front problem: it often carries less of the active compound than the studies used, in a form the one direct comparison suggests may not work. You are, functionally, buying a splash of vinegar, priced like a supplement, in the shape least likely to do the thing.

The verdict: Oversold

Apple cider vinegar supplements are not a scam. That word belongs to products with no kernel of truth, and this category has one. Acetic acid does a little something, mostly for blood sugar and triglycerides, mostly in people with a metabolic problem, at a dose and in a form the pills and gummies tend not to match.

What the supplement aisle does is take that little something and sell it back to you as medicine: at a markup, with outcome claims propped up by FDA disclaimers, “centuries of tradition”, and vitamins doing the real work, for benefits most buyers don’t need. That’s not Gift, and it’s not Grift. It’s Oversold. Hype outrunning evidence.

So what should you actually buy?

Honestly? For most people, nothing.

If you’re a healthy adult buying this for weight, blood sugar, or “gut health,” there’s nothing here to fix, and the evidence for benefit in you is thin to nonexistent. If you have type 2 diabetes, the glucose evidence is real, but that’s a conversation with whoever manages your diabetes, not a shelf decision, especially given ACV’s interactions with insulin and diuretics. The answer to a metabolic condition is medical care, not a wellness gummy.

And if you simply like apple cider vinegar and want the modest, real signal that does exist? Skip the capsules and the gummies. Buy the plain liquid and take a tablespoon or two (15 to 30 mL) diluted in water before a meal, which is exactly what every positive trial actually used. Here’s the math, from one brand’s own shelf: Bragg sells the liquid at $10.99 for a 16-ounce bottle, about a month’s supply, and the capsules at $19.99 for 30 servings, for the same 750 mg of acetic acid. Same dose. Better-studied form. Half the price.

Or, you know. Put it in your collard greens. It’s really good there.

It’s food. Not medicine. Buy it like food.

Sources

Every figure in this piece was checked against the primary source. Verified references:

• Feise NK, Johnston CS. Vinegar form and postprandial glycemia. Journal of Nutrition and Metabolism, 2020. DOI: 10.1155/2020/9098739. PMID: 33489366.

• Valdes DS, So D, Gill PA, Kellow NJ. Effect of dietary acetic acid supplementation on plasma glucose, lipid profiles, and body mass index in human adults: a systematic review and meta-analysis. Journal of the Academy of Nutrition and Dietetics, 2021. DOI: 10.1016/j.jand.2020.12.002.

• Launholt TL, Kristiansen CB, Hjorth P. Safety and side effects of apple vinegar intake and its effect on metabolic parameters and body weight: a systematic review. European Journal of Nutrition, 2020. DOI: 10.1007/s00394-020-02214-3. PMID: 32170375.

• Jafarirad S, et al. The improvement effect of apple cider vinegar as a functional food on anthropometric indices, blood glucose and lipid profile in diabetic patients: a randomized controlled clinical trial. Frontiers in Clinical Diabetes and Healthcare, 2023. DOI: 10.3389/fcdhc.2023.1288786.

• Arjmandfard D, Behzadi M, Sohrabi Z, Mohammadi Sartang M. Effects of apple cider vinegar on glycemic control and insulin sensitivity in patients with type 2 diabetes: a GRADE-assessed systematic review and dose-response meta-analysis. Frontiers in Nutrition, 2025. DOI: 10.3389/fnut.2025.1528383.

• Kondo T, Kishi M, Fushimi T, Ugajin S, Kaga T. Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects. Bioscience, Biotechnology, and Biochemistry, 2009. DOI: 10.1271/bbb.90231.

• Khezri SS, Saidpour A, Hosseinzadeh N, Amiri Z. Beneficial effects of apple cider vinegar on weight management, visceral adiposity index and lipid profile in overweight or obese subjects receiving restricted calorie diet: a randomized clinical trial. Journal of Functional Foods, 2018. DOI: 10.1016/j.jff.2018.02.003.

• Abou-Khalil R, Andary J, El-Hayek E. Apple cider vinegar for weight management in Lebanese adolescents and young adults with overweight and obesity. BMJ Nutrition, Prevention & Health, 2024. RETRACTED 2025 (retraction notice DOI: 10.1136/bmjnph-2023-000823ret).

• Wang L, Cen S, Wang G, Lee YK, Zhao J, Zhang H, Chen W. Acetic acid and butyric acid released in large intestine play different roles in the alleviation of constipation. Journal of Functional Foods, 2020. DOI: 10.1016/j.jff.2020.103953. (Mouse study.)

• Madempudi RS, et al. Bacillus coagulans Unique IS2 in constipation: a double-blind, placebo-controlled study. Probiotics and Antimicrobial Proteins, 2020. DOI: 10.1007/s12602-019-09542-9.

• Hadi A, Pourmasoumi M, Najafgholizadeh A, Clark CCT, Esmaillzadeh A. The effect of apple cider vinegar on lipid profiles and glycemic parameters: a systematic review and meta-analysis of randomized clinical trials. BMC Complementary Medicine and Therapies, 2021. DOI: 10.1186/s12906-021-03351-w.

• American Association of Naturopathic Medical Colleges. “Benefits of Apple Cider Vinegar.” aanmc.org, 2026.

Brand pages (Bragg, Trace Minerals, HUM, Goli) captured with URL and timestamp; archived copies on file.

AG1 is clean. It is genuinely NSF Certified for Sport, which is real, third-party, batch-level testing, and one of the strongest quality certifications a supplement can carry. It is not contaminated. It is not dangerous. If you drink it, you are getting a tidy stack of vitamins and minerals in a form your body can absorb, plus some fiber and probiotics. Nobody is getting hurt here, unless you’re a bank account.

The problem is not safety. The problem is that a $79-a-month greens powder is sold on the promise of energy, immunity, better digestion, and a sharper brain. However, when you go looking for the evidence behind those specific promises, it’s not there. Not because the studies do not exist, they just measured blood vitamins, gut bacteria, and safety instead. And the one trial that did measure energy and well-being has not reported those results.

Let me show you.

What AG1 claims

AG1’s science page is beautiful, and it makes three moves worth quoting directly.

It says the product is backed by “four gold-standard clinical trials.” It says “the next generation of AG1 is clinically backed.” And it sells a benefits list: energy production, digestion and less bloating, immune defense, healthy brain and mood.

Those are strong words. “Gold-standard” and “clinically backed” are doing some seriously heavy lifting here, and a reasonable person (aka not me) reads them and assumes there is a solid pile of published evidence showing the product delivers those benefits.

So I went and pulled the evidence. All of it. Here is what is actually there.

The four “gold-standard” trials

First, credit where it is due: the trials are real, and the designs are legitimately rigorous. They are randomized, placebo-controlled, and several are triple-blind. That genuinely is the gold-standard study design, and I am not going to pretend otherwise. AG1 registered all of these on ClinicalTrials.gov, which is the right thing to do, and I could read every protocol.

Here is the full set, straight from the registry:

• A 120-person trial, 12 weeks, measuring blood biomarkers and the gut microbiome (NCT06332898).

• A 20-person trial in active adults, 2 weeks, measuring nutrient gaps and the microbiome (NCT06521424).

• A 40-person trial in adults with occasional GI issues, 2 weeks (NCT06564285).

• A 30-person trial, 4 weeks, that AG1 itself labels “exploratory” (NCT06181214).

• Plus an 8-hour bioavailability study in 16 people, which is where the “folate rises within 30 minutes” chart on their website comes from.

Add up the four headline trials and you get about 165 people total. The longest anyone was followed was 12 weeks. The shortest ran for 8 hours.

Every single one of the trials was primarily built to measure blood levels of vitamins, the composition of gut bacteria, and safety markers. Three of the four never measured the benefits on the label at all, no energy, no immunity, no mood, no “less bloating.” The fourth, the big one, did measure some of them, and I will get to what happened with that in a moment, because it is the spiciest part of this whole story.

A perfectly designed trial that measures blood folate tells you about blood folate. The rigor of the method does not change what the endpoint can show. You can run the most beautiful placebo-controlled trial in the world, and if it measures a vitamin level, it cannot tell you whether anyone felt more energetic.

The part that actually got me

Here is the wildest thing I found, and it is not an accusation, it is just what the public record shows.

AG1’s biggest trial, the 120-person one, did register some good outcomes. Buried in its ClinicalTrials.gov entry, alongside the biomarkers, are registered secondary outcomes for fatigue (a validated fatigue inventory) and well-being (the WHO-5 index). They measured energy. They measured well-being. They set out, in a rigorous trial, to answer exactly the question the marketing is built on.

And then the published result reports only the blood-vitamin numbers.

The abstract that came out of that trial (in an American Society for Nutrition journal supplement) reports vitamin C up 33 percent, folate up, homocysteine down, zinc unchanged. It does not report the fatigue results. It does not report the well-being results.

I want to be careful here, because this is exactly the kind of place where it would be easy to overreach, and overreaching is the whole thing this substack is built to avoid. I cannot tell you what the energy and well-being results were. Maybe they were null. Maybe they are still being written up. I am not claiming anyone hid anything, and I am not claiming intent. I am telling you the verified, checkable fact: the trial measured whether you feel better, and that data is not in the public record. The number that would actually justify the marketing is the one number that did not get published.

About those “published studies”

AG1’s site also lists some peer-reviewed research, and this is where the word “clinically backed” starts to wobble.

Of the eight papers listed, one is a human study. Four are in vitro, meaning they were conducted outside of a living organism. Their studies specifcally were run in a mechanical gut simulator (a system called SHIME that ferments stool in a series of vessels) or in cell cultures. Not in people. Not even in mice. Further, two of the cited articles are reviews written by AG1’s own staff, which do not test the product at all, they just summarize and evaluate other work done in a given field of research.

And the four “gold-standard” human trials? By AG1’s own accounting, on their own “clinical research lifecycle” page, the full manuscripts have not been published yet. What exists in the literature right now are conference abstracts and posters, presented at nutrition and sports-science meetings in 2025, plus one preprint. Conference abstracts are a legitimate, normal early step in science. But an abstract is a paragraph, not a full paper with methods and complete results you can actually scrutinize. “Clinically backed,” in this case, currently means “presented as posters, publication forthcoming.”

AG1 even concedes the core problem in its own words. In the bioavailability preprint, discussing the earlier in vitro work, the authors note that the gut-simulator model “limited accurate assessment of a wider array of nutrients which are more appropriately measured in vivo.” That is AG1 acknowledging that the test-tube data cannot tell you what actually happens in a human body. Which is precisely the gap between what they studied and what they sell.

So what did the good trial actually show?

Strip it all the way down and the flagship trial found this: people who do not eat many fruits and vegetables were low on some vitamins, and when you gave them a supplement containing those vitamins, their blood levels of those vitamins went up. Vitamin C rose. Folate rose. Homocysteine, a marker that tracks with folate, dropped. Zinc did not move.

That is a real result. It is also the least surprising result imaginable. If you give vitamins to people who are low on vitamins, their vitamin levels rise. This is not evidence that a proprietary greens blend does something special. It is evidence that the product contains the vitamins on its label and that those vitamins are absorbable, which, to be fair, is more than some supplements can say. But it is a very long way from “energy, immunity, and a sharper brain.”

One more thing worth knowing about the formula

AG1 markets “75-plus ingredients.” Most of the vitamins and minerals are listed individually with real doses, which is good. But the actual “greens,” the 42 botanicals and superfoods and phytonutrients that give the product its identity, are bundled into two large proprietary blends totaling 9 grams, with no per-ingredient doses disclosed.

That matters because dose is everything. Ashwagandha, for example, has real evidence at a specific studied dose. AG1 contains ashwagandha, somewhere inside a 7.5-gram blend, at an amount they do not disclose. So there is no way to know whether you are getting a meaningful dose or a pinch. A long, impressive ingredient list with hidden doses tells you what is in the tub, not whether any of it is present in an amount that does anything.

The verdict: Grift

Not because it is unsafe. It is clean, tested, and honestly formulated in the sense that what is on the label is in the tub.

It earns the Grift because the marketing sells proven benefits that the evidence does not support. Most of the trials measured biomarkers, microbiome, and safety, not the benefits on the label. The one trial that did measure energy and well-being has not reported those results. The publications list are mostly test tubes and staff-written reviews. The doses that matter are hidden. And you are paying about $948 a year for it.

And here is the part I keep coming back to, the reason I chose AG1 specifically and not one of the dozens of cheaper greens powders: the marketing is genuinely, disarmingly excellent. It is beautiful. It is calm and clinical and reassuring, and it uses the real vocabulary of science (”gold-standard,” “clinically backed,” “peer-reviewed”) with real citations attached. I almost fell for it myself it once, years ago, purely because the marketing was that good. That polish is not a reason to trust it. It is the reason to check.

What to buy instead

Nothing, probably.

For a well-nourished adult with no diagnosed deficiency, there is no proven benefit here over eating actual food. And AG1’s own flagship trial makes the point for me: the people in it were low on vitamins because they were not eating enough fruits and vegetables, and adding vitamins fixed their blood numbers. You know what else fixes that? Fruits and vegetables. The problem the study describes has a solution that costs a lot less than $79 a month and comes with fiber, and satiety, and everything else in whole food that no powder reproduces.

If you have a diagnosed deficiency, treat that specific deficiency, with your doctor, using the specific nutrient you are low on. That is targeted and cheap.

Credit where it is due, one more time: AG1 is NSF Certified for Sport, which is a genuine mark of a clean, tested product. Just remember what that certification means. It certifies the product is pure and free of banned substances. It does not certify that it works.

Gift / Grift — evidence over hype. Every claim gets a citation; every figure is checked against a primary source before it runs.

Sources

Registered trials (ClinicalTrials.gov), sponsor Athletic Greens International:

[1] NCT06332898 — 120 adults, 12 weeks, nutrient biomarkers and microbiome; registered secondary outcomes include fatigue and well-being. https://clinicaltrials.gov/study/NCT06332898

[2] NCT06521424 — 20 active adults, 2 weeks, nutrient gaps and microbiome. https://clinicaltrials.gov/study/NCT06521424

[3] NCT06564285 — 40 adults with occasional GI issues, 2 weeks. https://clinicaltrials.gov/study/NCT06564285

[4] NCT06181214 — 30 adults, 4 weeks, “exploratory.” https://clinicaltrials.gov/study/NCT06181214

[5] NCT07436911 — GLP-1 users, registered and recruiting; no results yet. https://clinicaltrials.gov/study/NCT07436911

Published abstract (flagship biomarker trial):

[6] Edwards C, Townsend JR, Sapp PA, Kirby TO, et al. AG1 Improves Biomarkers of Nutrient Status: A Randomized Controlled Trial. Current Developments in Nutrition. 2025;9:107408 (NUTRITION 2025 abstract supplement). https://doi.org/10.1016/j.cdnut.2025.107408

Preprint (bioavailability / the “30-minute folate” chart):

[7] Sapp PA, Townsend JR, Kirby TO, et al. Absorption Kinetics of Vitamins and Minerals from a Novel Nutritional Product in Healthy Adults: A Randomized, Double Blind, Placebo-Controlled Crossover Trial. medRxiv, 2026. https://doi.org/10.64898/2026.01.05.25342664v1

In vitro and review papers listed on AG1’s site:

[8] SHIME gut-simulator study. Current Issues in Molecular Biology. 2024. https://doi.org/10.3390/cimb46010036

[9] SHIME short-chain fatty acid study. Nutraceuticals. 2023. https://doi.org/10.3390/nutraceuticals3040035

[10] SHIME fecal metabolome (”proof of principle”) study. Journal of Functional Foods. 2024. https://doi.org/10.1016/j.jff.2024.106319

[11] Caco-2/THP1 cell-culture study. Microorganisms. 2024. https://doi.org/10.3390/microorganisms12071263

[12] Mineral bioaccessibility (in vitro upper-GI model). Applied Biosciences. 2023. https://doi.org/10.3390/applbiosci2040041

[13] “Foundational Nutrition” review (AG1-authored). Nutrients. 2023. https://doi.org/10.3390/nu15132837

[14] “Nutrient synergy” review (AG1-authored). Frontiers in Nutrition. 2023. https://doi.org/10.3389/fnut.2023.1279925

AG1 product page, “scientific research” page, “AG1 at scientific conferences” abstract list, and Supplement Facts panel captured and archived July 2026. NSF Certified for Sport status confirmed via the NSF database.

So this isn’t a takedown of creatine. It’s a look at what happens to a genuinely good molecule when marketing gets hold of it: inflated claims, upcharges for gummies, the citations that don’t say what they are claimed to say. Because the tell of a grift isn’t that the product is worthless. I think often times, there are crumbs of truth to many claims in the wellness industry. It’s that the story around it has drifted from the evidence. And with creatine, the drift is easy to see once you know where to look.

Here’s what I found pulling the claims off three popular creatine brands and checking them against the primary literature.

What the research actually says

Strength and power: solid. This is the part that’s earned. Creatine’s effect on strength, power output, and high-intensity performance is about as well-established as anything in sports nutrition. If a brand says creatine helps you get stronger alongside training, they’re right, and the citations back them up.

Muscle size: real, but smaller than the labels imply… and it’s partly water. This is where the first bit of drift shows up. For years the standard claim has been that creatine adds a kilo-plus of “lean mass.” The problem is how that mass was measured. Most studies used DXA or bioelectrical impedance, which lump muscle and water together as “lean mass.” When researchers measure actual muscle with direct imaging instead (MRI, CT, ultrasound) the extra gain from creatine shrinks to a much smaller value. A 2023 meta-analysis by Burke and colleagues found the added muscle thickness from creatine plus training, over training alone, was in the range of a tenth of a centimeter [1]. A 2025 randomized trial went further: it added a one-week “wash-in” phase with no exercise, and found the creatine group’s apparent lean-mass advantage showed up before anyone had trained which is consistent with creatine pulling water into muscle rather than building it [2].

So: creatine helps you build muscle alongside training, but the size effect is modest, and some of what the scale and the DXA scan call “muscle” is actually just water. That doesn’t make it useless. It makes “build lean muscle” an overstatement of a real thing.

Memory and cognition: promising, not proven. This is the frontier, and it’s where the marketing is sprinting ahead of the evidence. There is real, interesting research here. A 2024 meta-analysis found a positive effect of creatine on memory, with the strongest signal in older adults [3], however the same analysis rated the certainty of that memory effect as moderate, and the evidence for other cognitive domains as low. Mood effects, on the other hand, are mixed [4]. The honest summary is: creatine may support memory, the effect is probably clearest in people under some kind of stress (sleep deprivation, aging, low dietary intake) and it is nowhere near “creatine makes you will raise your IQ.” Keep that calibration in mind, because you’re about to see brands throw it out entirely.

The catch, part one: you’re paying for the marketing

Creatine monohydrate is one of the cheapest interventions in all of wellness. Bought as a plain powder, it runs somewhere around forty cents a day at the standard five-gram dose. I know because I bought a tub to try myself and did the math.

Now here’s what the same molecule costs dressed up in fancy clothes:

• Legion creatine gummies: about $40 a month.

• MindBodyGreen creatine (with taurine): $65 a month.

• Create creatine gummies: $73 for a one-time purchase… or $58 if you agree to monthly autoshipments.

Same five grams of creatine at the core of each. The price difference is brand, format, and in one case the addition of another amino acid. Gummies in particular carry a heavy convenience premium and added ingredients such as tapioca powder, sugar, pectin and allulose.

And notice that Create pricepoint. Seventy-three dollars if you buy it once; fifty-eight if you hand over your recurring billing information. That fifteen-dollar gap is the whole subscription game in miniature: the “sale” price is contingent on a commitment most people forget they made. The sticker you see advertised is frequently the subscribed price, which means the real cost of trying it once is higher than advertised.

None of this makes these products scams, they are just expensive ways to buy a cheap molecule, and the more a brand leans on format and subscription to justify the price, the more it’s worth asking what you’re actually paying for.

The catch, part two: when the citation doesn’t say what they claim

This is the part that turned my head, and it’s the reason I care about this beyond price.

Good supplement marketing has learned to look evidence-based. Footnotes, superscripts, “clinically studied,” charts with citations underneath. The presence of a citation reads as rigor. But a citation is only as good as what’s actually in the paper cited and that’s something almost no one checks. So I checked.

One brand’s science page featured a chart titled “Memory Improvement With Creatine,” with a bold claim about a twenty percent boost in memory performance, sourced to a specific study. When I pulled that study, it was a resistance-training paper about muscle fiber adaptations. I searched the full text. It contains no measure of memory, no measure of cognition, and not even the age group shown on the chart. The citation is real. The paper exists. It simply has nothing to do with the claim it’s being used to support.

That’s a different thing from overselling. Overselling is stretching what a study found. This is attaching a real study to a finding it never made, on the exact claim — cognition — where the underlying scientific evidence is weakest. The footnote is doing the work of making an unsupported claim look sourced.

A subtler version of the same move: another brand supports its “creatine for your brain” messaging by citing a legitimate review of creatine’s role in cellular energy metabolism. That paper is real and correct as creatine genuinely helps regenerate ATP in high-demand tissue, including the brain. But “creatine is involved in brain energy metabolism” is a statement about mechanism, not a demonstration that taking creatine gummies measurably improves your memory. The citation is accurate; it’s just being asked to prove something it doesn’t prove. Mechanism dressed up as outcome.

To be fair (this matters, because the point isn’t that every brand is lying) one of the three brands I looked at has a genuinely solid reference list: real, mostly primary sources that broadly support its strength and performance claims. Its cognition claim was the weak spot, resting on a customer testimonial rather than a study. But credit where it’s due: honest sourcing for the claims that had it.

The lesson isn’t “never trust a cited claim.” It’s that a citation is a pointer, not a proof, and the pointer is worth following. When a brand shows you a chart with a study underneath, the useful question is not “is there a citation” but “does the citation say this.”

A word on “third-party tested” and other reassuring phrases

Because supplements aren’t reviewed by the FDA before they’re sold, third-party testing is genuinely valuable. It’s the closest thing to an outside check that a product contains what the label says and isn’t contaminated. But the phrase gets used loosely, and the tiers actually mean different things:

• NSF Certified for Sport and Informed Sport are the strongest marks. They involve batch-level or full-program testing against banned substances, and you can verify them.

• Informed Choice uses the same lab and methods as Informed Sport but tests monthly retail samples rather than every batch. Still legit, but a tier down.

• A plain “NSF” mark is not the same as “NSF Certified for Sport,” and brands sometimes let you assume it is.

• And “lab-tested,” “quality tested,” or an official-looking in-house badge with no named certifier behind it means whatever the brand wants it to mean. This is the brand cosplaying third-party testing.

One important caveat that fits everything above: third-party testing certifies that a product is what it says and is uncontaminated. It does not certify that the product works. It’s a purity check, not an efficacy stamp. The same way an ingredient being “generally recognized as safe” is a regulatory technicality, not the FDA vouching that it does anything. Don’t let a testing badge do the job of real bonafide evidence.

The verdict

Creatine monohydrate is a gift. Cheap, safe in healthy adults, and genuinely effective, especially for strength. A rare unambiguous win on a shelf full of overpriced hope.

The grift, where it exists, is in the packaging around it: the gummies at a multiple of the powder’s price, the subscriptions that make the “deal” contingent on the customer forgetting to cancel, the brain claims that outrun the evidence, and the footnotes that point to studies that don’t say what they’re cited for.

So here’s what to actually do, if creatine sounds like it might be for you:

Buy plain creatine monohydrate. Not the fancy “buffered” or “HCl” forms — they cost more and haven’t been shown to beat plain monohydrate. Skip the gummies unless you truly won’t take it otherwise.

Aim for about five grams a day. That’s the standard effective dose.

Pick the cheapest option that’s third-party tested — look for NSF Certified for Sport or Informed Sport specifically, or even Informed Choice (that’s what I went with). And match the certification to your actual risk: the every-batch, athlete-grade testing exists to protect drug-tested competitors. If that’s not you, a reputable tested tub is plenty; you don’t need to pay the athlete premium.

Skip anything that’s only “cheap” if you subscribe.

Creatine is the gift. Everything the marketing staples onto it is the part to watch.

Gift / Grift — evidence over hype. Every claim gets a citation; every figure is checked against a primary source before it runs.

Sources

[1] Burke R, et al. The effects of creatine supplementation combined with resistance training on regional muscle hypertrophy: a systematic review and meta-analysis. Nutrients. 2023;15(9):2116. https://doi.org/10.3390/nu15092116

[2] Hagstrom AD, et al. [Creatine wash-in / lean mass RCT.] Nutrients. 2025. https://doi.org/10.3390/nu17061081

[3] [2024 creatine and cognition meta-analysis — memory outcomes and GRADE ratings.] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11275561/

[4] [2025 review — creatine and mood/mental health; mixed evidence.] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12823350/

Additional: ISSN position stand on creatine safety and dosing (2025); brand claims and citations captured from manufacturer product and science pages, July 2026, with the underlying studies checked individually.