Foundayo produced 11.1% mean weight loss at its maximum dose over 72 weeks in adults with obesity and without diabetes, against 2.1% on placebo. That is the number every summary quotes, and on its own it is the least useful figure the label publishes. The same table shows that 71.5% of patients on that dose lost at least 5% of their body weight, 54.5% lost at least 10%, and 18.4% lost at least a fifth. The average describes nobody.
The full results, by dose
Foundayo's approval rests on two 72-week trials: Trial 1 in 3,127 adults with obesity or overweight plus a weight-related condition and no diabetes, and Trial 2 in 1,613 adults with type 2 diabetes. Both tested three doses against placebo. Here is what the label reports.
| Trial 1 — no diabetes | Placebo | 5.5 mg | 9 mg | 17.2 mg |
|---|---|---|---|---|
| Mean weight change | −2.1% | −7.4% | −8.3% | −11.1% |
| Lost at least 5% | 26.8% | 59.6% | 63.1% | 71.5% |
| Lost at least 10% | 13.0% | 32.5% | 39.8% | 54.5% |
| Lost at least 15% | 6.0% | 14.3% | 20.1% | 35.9% |
| Lost at least 20% | 2.9% | 5.9% | 8.9% | 18.4% |
Participants started at a mean weight of 103.2 kg and a mean BMI of 37. Mean age was 45, and 64% were women.
The same drug in people with type 2 diabetes
Trial 2 ran the identical design in adults with type 2 diabetes and a mean HbA1c of 8%. Every figure is lower, which is the pattern across this whole drug class rather than anything specific to Foundayo.
| Trial 2 — with type 2 diabetes | Placebo | 5.5 mg | 9 mg | 17.2 mg |
|---|---|---|---|---|
| Mean weight change | −2.5% | −5.1% | −7.0% | −9.6% |
| Lost at least 5% | 26.8% | 47.4% | 54.7% | 67.0% |
| Lost at least 10% | 9.2% | 22.5% | 31.1% | 45.6% |
| Lost at least 15% | 3.1% | 6.7% | 14.4% | 25.9% |
| Lost at least 20% | 0.7% | 2.6% | 4.4% | 10.8% |
The gap is roughly a point and a half of body weight at every dose. If you have type 2 diabetes, the second table is your table.
Why the average is the wrong number to plan around
Look down the 17.2 mg column of Trial 1. The mean is 11.1%, but the outcomes behind it spread from people who lost nothing to 18.4% who lost more than a fifth of their body weight. Nearly three in ten did not reach even 5%.
That spread is not noise, and it is not a failure of the drug. It is what every weight-loss medication looks like when you stop averaging: a wide distribution that a single number flattens. Planning around 11.1% is planning around a figure that describes the middle of a range you cannot know your position in until you have taken it for several months.
The practical reading is that the responder rows matter more than the mean row. A 71.5% chance of losing at least 5%, and a better-than-even chance of losing at least 10%, is a more honest way to hold the expectation than "about 11%".
The number that runs the other way
In Trial 1, the proportion who stopped taking the trial drug was 22% on 5.5 mg, 22% on 9 mg and 24% on 17.2 mg — against 30% on placebo. More people abandoned the sugar pill than abandoned the drug at any dose.
This is worth sitting with, because it contradicts the assumption most people bring to a GLP-1: that the side effects are the thing most likely to end the treatment. In a 72-week trial the more common reason to stop is that nothing is happening. Trial 2, where placebo patients were also managing diabetes, showed no such gap: 19–22% across all four arms.
How this compares with the injections
Foundayo is the weakest of the approved weight-loss drugs on this measure, and it is not close. Semaglutide reached about 14.9% in STEP-1 and tirzepatide about 20.9% in SURMOUNT-1, against Foundayo's 11.1%.
Those are separate trials in different populations, so the comparison is indicative rather than a race. But the ordering is not in doubt, and the label does not pretend otherwise.
What Foundayo has instead is the form. It is a small molecule, not a peptide, which is why it can be swallowed with no rules about food or water — unlike rybelsus-for-weight-loss">oral semaglutide, which requires an empty stomach, a small sip of water and a thirty-minute wait. Whether a tablet you will actually take beats an injection you will not is a real question, and for a lot of people the answer is yes. The full ranking across drugs is in the best GLP-1 for weight loss, and the drug itself in Foundayo explained.
How long it takes
Both trials measured at 72 weeks, and the label reports no intermediate timepoints in text. What the dosing schedule does tell you is the shape of the first five months: you start at 0.8 mg and step up no sooner than every 30 days through 2.5, 5.5, 9 and 14.5 mg, reaching the 17.2 mg maximum around day 150 at the earliest.
So the results above are results at the top dose after more than a year, in people who spent the first third of that climbing to it. Anyone comparing their month-three weight against 11.1% is comparing against a different thing.
Scientific References
3 sources- 1
Eli Lilly and Company
FOUNDAYO (orforglipron) tablets — Prescribing Information, §14 Clinical Studies, Table 6: Changes from Baseline in Body Weight at Week 72 in Trials 1 and 2
DailyMed, U.S. National Library of Medicine · 2026
NIH - 2
Wilding JPH, Batterham RL, Calanna S, et al.
Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP-1)
New England Journal of Medicine · 384(11) · 2021PMID: 33567185
NEJM - 3
Jastreboff AM, Aronne LJ, Ahmad NN, et al.
Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1)
New England Journal of Medicine · 387(3) · 2022PMID: 35658024
NEJM
References open in a new tab. Content is reviewed against peer-reviewed literature as part of our editorial policy.
About the author
Editor, Modern Weight Science
Claudiu Gheorghe is the editor of Modern Weight Science. He is not a physician. His role is to synthesize peer-reviewed studies, clinical-trial data, and FDA prescribing information into clear, plain-language explanations, and to make sure every factual claim on the site traces back to a cited source. Any decision about starting, changing, or stopping a medication belongs with a licensed clinician who knows your history.
Every claim is checked against peer-reviewed research through our review process and fact-checking policy.
Frequently Asked Questions
How much weight do you lose on Foundayo?
At the 17.2 mg maximum dose, mean weight loss was 11.1% over 72 weeks in adults with obesity and without diabetes, against 2.1% on placebo. The averages hide a wide spread: 71.5% of patients lost at least 5% of body weight, 54.5% at least 10%, 35.9% at least 15% and 18.4% at least 20%. In adults with type 2 diabetes the mean was 9.6%.
Is Foundayo as effective as Ozempic or Zepbound?
No. Foundayo's 11.1% sits below semaglutide's roughly 14.9% in STEP-1 and tirzepatide's roughly 20.9% in SURMOUNT-1. Those are separate trials in different populations, so the comparison is indicative rather than head-to-head, but the ordering is not in doubt. What Foundayo offers instead is a tablet with no food or water restrictions.
How much weight loss on the lower Foundayo doses?
In adults without diabetes, mean weight loss was 7.4% at 5.5 mg and 8.3% at 9 mg, against 11.1% at 17.2 mg and 2.1% on placebo. The dose-response is clearest in the responder figures: the proportion losing at least 20% of body weight rose from 5.9% at 5.5 mg to 8.9% at 9 mg to 18.4% at the maximum dose.
How long does Foundayo take to work?
Both trials measured weight at 72 weeks and the label publishes no intermediate timepoints in text. The dosing schedule sets the shape of the early months: starting at 0.8 mg with steps no sooner than every 30 days through 2.5, 5.5, 9 and 14.5 mg, the 17.2 mg maximum is not reached before roughly day 150. Results at three months are not comparable to the 72-week figures.
Do many people stop taking Foundayo?
Fewer than stopped placebo, in the trial without diabetes: 22% discontinued on 5.5 mg, 22% on 9 mg and 24% on 17.2 mg, against 30% on placebo. In the type 2 diabetes trial the rates were 19% to 22% across all arms including placebo. That runs against the common assumption that side effects are the most likely reason a GLP-1 course ends.
Does Foundayo work as well in people with type 2 diabetes?
Less well, which is the pattern across this drug class rather than something specific to Foundayo. At 17.2 mg the mean was 9.6% against 11.1% in the trial without diabetes, and 45.6% reached at least 10% weight loss against 54.5%. The gap is roughly a point and a half of body weight at every dose.
Continue learning
Where to read next
Not medical advice. This guide is for general education only. GLP-1 medications, dosing, and treatment suitability are decisions for you and a licensed clinician who knows your full medical history.