Let me say the fair part first, because this post is going to be critical and I want to be honest about what AG1 gets right.
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.