Foundayo Results: How Much Weight People Actually Lost in the Trials

If you search for how much weight people lose on Foundayo (orforglipron), you will find at least four different numbers: 27.3 pounds, 25 pounds, 12.4% and 11.1%. All four are correct. They come from the same trial, analyzed different ways.

This article sorts that out, then walks through every published Foundayo result: the obesity trials, the diabetes trials, the switching trial, and the subgroup analyses. It ends with what the studies genuinely do not show, which matters just as much.

This is a description of published research. It is not advice about whether to take this or any medicine, and it is not a prediction of what would happen to you. Averages in a trial are not a forecast for an individual.

What is the headline Foundayo weight loss number?

ATTAIN-1 is the trial that carries it. It enrolled 3,127 adults with obesity, or overweight plus a weight-related condition, excluding people with diabetes. Average age 45, 64% women, average starting weight 227.5 pounds and average BMI 37. It ran 72 weeks across ten countries and territories — the US, Brazil, China, India, Japan, South Korea, Puerto Rico, Slovakia, Spain and Taiwan — randomizing people to three Foundayo doses or placebo in a 3:3:3:4 ratio [1][2][3].

At 72 weeks, at the top 17.2 mg dose:

• Efficacy estimand (what would have happened if everyone had stayed on drug): 27.3 pounds, or 12.4%, versus 2.2 pounds or 0.9% on placebo [1].
• Treatment-regimen estimand (counting everyone regardless of whether they stopped): 11.2%, roughly 25 pounds, versus 2.1% (roughly 5 pounds) on placebo, as published in the New England Journal of Medicine [1][12].
• The FDA label, which uses intent-to-treat with modified multiple imputation: 11.1%, versus 2.1% on placebo, a placebo-adjusted difference of 9.0 percentage points [3].

The lower doses landed where you would expect. Efficacy estimand: 7.8% at 5.5 mg, 9.3% at 9 mg, 12.4% at 17.2 mg [1]. The label’s intent-to-treat figures for the same doses: 7.4%, 8.3%, 11.1%, from mean baseline weights of 103.2, 102.2 and 103.1 kg [3].

Which number should you use? If you are asking “what does this drug do at full dose in someone who tolerates it,” the efficacy estimand. If you are asking “what happened on average to everyone who was prescribed it,” the treatment-regimen estimand or the label figure. Honest coverage names which one it is quoting. A lot of coverage does not.

What share of people hit specific weight loss milestones?

Averages hide the spread. These proportions from ATTAIN-1 are more useful for most readers, shown at 5.5 mg / 9 mg / 17.2 mg against placebo, efficacy estimand [1]:

Milestone	5.5 mg	9 mg	17.2 mg	Placebo
Lost 5% or more	63.8%	69.3%	77.1%	22.1%
Lost 10% or more	35.9%	45.1%	59.6%	8.6%
Lost 15% or more	16.5%	24.0%	39.6%	3.6%
Lost 20% or more	7.2%	11.4%	20.1%	1.6%

The label’s intent-to-treat analysis is more conservative across the board. Its Trial 1 table prints, at 5.5 / 9 / 17.2 mg against placebo [3]:

Milestone	5.5 mg	9 mg	17.2 mg	Placebo
Lost 5% or more	59.6%	63.1%	71.5%	26.8%
Lost 10% or more	32.5%	39.8%	54.5%	13%
Lost 15% or more	14.3%	20.1%	35.9%	6%
Lost 20% or more	5.9%	8.9%	18.4%	2.9%

Both tables are legitimate. They differ because they answer different questions, and because the label imputes missing data for the 14% to 24% of participants whose week-72 weight was never recorded [3].

Read the top dose column carefully. About one in five people lost 20% or more of their body weight. About one in four did not reach even 5%. Response to GLP-1 drugs varies enormously between individuals, and that variation is visible right there in the trial data.

What else changed besides weight?

ATTAIN-1 tracked more than the scale [1]:

• Waist circumference: down about 4.4 inches (11.1 cm) at the top dose on the efficacy estimand. The label’s intent-to-treat table prints a 10.0 cm reduction at 17.2 mg versus 3.1 cm on placebo [3].
• Systolic blood pressure: down about 6.7 mm Hg on the efficacy estimand. The label prints a 6.4 mm Hg fall at 17.2 mg versus 1.4 mm Hg on placebo, a 4.9 mm Hg placebo-adjusted difference [3].
• Triglycerides: down 21.6% versus 4.8%.
• hsCRP, a marker of inflammation: down 47.7% at the top dose, a pre-specified exploratory endpoint.
• Prediabetes: among 1,127 participants who had prediabetes at the start, up to 91% returned to near-normal blood sugar versus 42% on placebo.

That prediabetes finding is significant enough that the trial has an extension running to week 176 specifically to measure how long it takes type 2 diabetes to develop in that group [2].

One design detail deserves attention for anyone comparing trials. Lilly describes ATTAIN-1 as the first Phase 3 trial in this population run as an adjunct to exercise and a balanced healthy diet, rather than a reduced-calorie diet [1]. Other obesity trials, including the SURMOUNT and STEP programs, used a calorie-restricted backdrop. Everyone in a calorie-deficit trial, including the placebo group, tends to lose more. That is one reason ATTAIN-1’s placebo group lost only 0.9% to 2.1% while placebo groups in other obesity trials often lost 2% to 3%.

What happened in people who also had type 2 diabetes?

ATTAIN-2 ran the same three doses against placebo in 1,613 adults with both excess weight and type 2 diabetes, a group that typically loses less weight on incretin therapy. Average age 57, average starting weight 223.5 pounds, average A1C 8.1% [4].

At 72 weeks on the top dose, efficacy estimand: 10.5%, or 22.9 pounds, versus 2.2% on placebo. The treatment-regimen figure was 9.6% or 21.2 pounds. The label reports 9.6% versus 2.5% [3][4].

Blood sugar moved substantially too: A1C fell 1.3 to 1.8 points across doses from a baseline of 8.1%, and 75.0% of people on the top dose reached an A1C of 6.5% or below versus 10.6% on placebo [4]. Half of the top-dose group lost 10% or more of their body weight.

Foundayo is not FDA-approved for type 2 diabetes in the United States as of September 14, 2026. Lilly’s second-quarter 2026 earnings release, published August 5, 2026, lists the US type 2 diabetes submission for orforglipron among that quarter’s regulatory progress; the FDA has announced no decision. The United Kingdom authorized both indications on August 10, 2026 [3][14].

How did Foundayo do against another GLP-1 pill?

ACHIEVE-3 is the first and so far only head-to-head Phase 3 trial between two oral GLP-1 receptor agonists. It randomized 1,698 adults with type 2 diabetes on metformin to Foundayo or oral semaglutide for 52 weeks, starting from an average A1C of 8.3% and average weight of 213.9 pounds [5].

Foundayo won on the primary endpoint and every key secondary endpoint:

Result at 52 weeks	Foundayo 9 mg	Foundayo 17.2 mg	Semaglutide 7 mg	Semaglutide 14 mg
A1C change	-1.9	-2.2	-1.1	-1.4
Weight change	-6.7% (14.6 lb)	-9.2% (19.7 lb)	-3.7% (7.9 lb)	-5.3% (11.0 lb)
A1C under 7%	80.0%	85.4%	54.6%	66.1%
A1C under 5.7%	25.4%	37.1%	7.8%	12.5%
Stopped for side effects	8.7%	9.7%	4.5%	4.9%

At the top-dose comparison, that is a 57.1% greater relative A1C reduction and a 73.6% greater relative weight loss [5]. The results were published in The Lancet on February 26, 2026.

The caveat is important and Lilly does not hide it. The comparator was oral semaglutide at its diabetes doses, 7 mg and 14 mg, sold as Rybelsus. It was not the 25 mg Wegovy weight-management tablet. The trial was open-label, and it enrolled people with diabetes, not a general weight-management population. ACHIEVE-3 does not tell you which pill produces more weight loss in someone without diabetes.

Novo Nordisk’s own indirect analysis, ORION, published one day after Foundayo’s approval, argued the opposite for the weight-loss question: that the 25 mg Wegovy tablet produced significantly greater weight loss than orforglipron, with far fewer GI-related discontinuations. That was a population-adjusted comparison stitched together across two separately run trials, not a head-to-head study, and it was sponsored by the company selling the competing product.

What happens if you switch from an injection to the pill?

This is one of the most-asked questions about Foundayo, and there is exactly one randomized trial that speaks to it.

ATTAIN-MAINTAIN enrolled 376 people who had completed SURMOUNT-5 on maximum tolerated doses of Wegovy (1.7 or 2.4 mg) or Zepbound (10 or 15 mg) and had reached a weight plateau. They were re-randomized 3:2 to Foundayo or placebo — 205 coming off tirzepatide and 171 off semaglutide — started at the 9 mg tablet-equivalent dose, and titrated every four weeks toward a maximum tolerated 14.5 or 17.2 mg. “Plateau” was defined as less than 5% body-weight change between weeks 60 and 72 of SURMOUNT-5 [6].

After 52 weeks:

• People who switched from Wegovy kept all but about 0.9 kg, roughly 2 pounds, of their prior weight loss.
• People who switched from Zepbound kept all but about 5.0 kg, roughly 11 pounds.
• Summaries of the paper describe participants as retaining roughly 75% to 82% of their prior weight loss depending on cohort and on which figure is quoted, against roughly 38% to 49% on placebo. Treat the percentage as a range rather than a single number [6].
• The placebo groups did far worse. In a post-hoc look at week 24, before placebo participants could be rescued, they had regained 9.4 kg and 9.1 kg while the Foundayo groups had changed by -0.1 kg and +2.6 kg [6].

Two things the trial does not tell you. It compared switching to Foundayo against switching to placebo, not against staying on the injectable. And every participant started at the 9 mg tablet-equivalent, well up the ladder. Whether starting a switcher at 0.8 mg produces the same outcome is not something this trial answers, and Lilly’s own consumer FAQ declines to name a starting dose for switchers, routing that decision to a doctor. Patient reports from people restarted near the bottom of the ladder after high-dose tirzepatide frequently describe hunger returning and several pounds of regain during titration [7]. Anecdote, but consistent anecdote.

Do results differ by age or menopausal status?

Two post-hoc analyses of the ATTAIN trials looked at this.

Adults 65 and older. Announced May 22, 2026 and published in Obesity Pillars in July 2026, this analysis reported body weight reduction of up to about 13% in older adults with obesity or overweight, with or without type 2 diabetes [8]. The label separately records that 399 Foundayo-treated patients (13% of the pooled group) were 65 or older and 33 were 75 or older, with no overall differences in safety or effectiveness observed between older and younger adults [3].

Menopausal stage. Presented at ADA 2026, a post-hoc analysis of more than 1,500 women on the 17.2 mg dose found weight loss at every stage. In ATTAIN-1, pre-, peri- and post-menopausal women lost 28.0 lb (12.8%), 30.4 lb (14.4%) and 28.2 lb (14.1%) at 72 weeks. In ATTAIN-2, the figures were 23.4 lb (11.3%), 18.5 lb (8.9%) and 27.8 lb (13.6%). Up to 51.5% of women in ATTAIN-1 lost at least 15% [9].

Both are post-hoc subgroup analyses, not pre-specified endpoints, and some subgroups were small. They are suggestive, not definitive.

What do the diabetes trials add?

Four other Phase 3 trials round out the picture, all in type 2 diabetes:

• ACHIEVE-1 (559 people, 40 weeks, versus placebo): the first Phase 3 win for an oral small-molecule GLP-1 anywhere. A1C down 1.3 to 1.6 points versus 0.1; weight down 7.9% (16.0 pounds) at the top dose. The investigators noted weight had not plateaued at 40 weeks.
• ACHIEVE-2 (962 people, 40 weeks, versus dapagliflozin): A1C down up to 1.7 points versus 0.8; weight down up to 7.3%.
• ACHIEVE-5 (546 people, 40 weeks, added to insulin glargine): A1C down up to 2.1 points versus 0.8 on placebo; weight down up to 6.1% versus a 0.6% gain.
• ACHIEVE-4 (2,749 people, 104 weeks, versus insulin glargine): the longest Foundayo trial. Covered below.

Does Foundayo protect your heart?

Not as an approved claim. Here is what exists.

ACHIEVE-4 enrolled 2,749 adults with type 2 diabetes, BMI 25 or above and elevated cardiovascular risk across 16 countries, and ran up to 104 weeks against insulin glargine. Its primary endpoint was cardiovascular safety, not benefit [10].

Foundayo met non-inferiority with a hazard ratio of 0.84 for four-component major adverse cardiovascular events (95% CI 0.59 to 1.20), an observed 16% lower risk, and 0.77 for the three-component version. In a pre-planned analysis not controlled for multiple comparisons, all-cause death was 57% lower with Foundayo than with insulin glargine (HR 0.43, 95% CI 0.25 to 0.75, nominal p = 0.002). A1C fell 1.6 points versus 1.0, and weight fell 8.8% versus a 1.7% gain on insulin. A thorough liver-injury analysis found no hepatic safety signal [10].

Three reasons not to overread it: the comparator was insulin, not placebo or another GLP-1; the mortality result was not multiplicity-controlled; and the population was people with diabetes, not the obesity population Foundayo is approved for.

The trial that could eventually support a cardiovascular benefit claim is ATTAIN-Outcomes, which began enrolling 7,140 people with cardiovascular or kidney disease in December 2025 and has an estimated primary completion of August 2031 [11]. Until then, Foundayo carries no cardiovascular indication, while the Wegovy pill and injection do.

What do the trials not show?

This is the honest inventory.

• No head-to-head against injectables. There is no randomized trial of Foundayo against Zepbound or injectable Wegovy. Cross-trial, SURMOUNT-5 reported 20.2% for Zepbound and 13.7% for injectable Wegovy over the same 72 weeks that ATTAIN-1 reported 12.4% for Foundayo. Different trials, different populations, different lifestyle backdrops. It is a rough signal, not a measurement.
• No head-to-head against the 25 mg Wegovy tablet in people without diabetes.
• No cardiovascular outcomes data until roughly 2031.
• No pediatric data. The adolescent studies are ongoing and no pediatric indication exists.
• No published real-world cohort study. Foundayo has been on the US market since April 2026. Everything outside the trials is currently anecdote, including the Drugs.com reviews (a 7.0 average from 40 reviews, a figure carried forward from an earlier check — Drugs.com blocks automated re-verification, so treat it as approximate) and the substantial weight-loss stories posted in the Foundayo communities. Individual results posted online are self-selected, unverified and have no control group.
• No long-term data beyond 72 weeks in the obesity population, except the 104-week ACHIEVE-4 diabetes trial and the ongoing ATTAIN-1 extension.

One more thing about the numbers you will read

Every Phase 3 trial was run with an investigational orforglipron capsule dosed at 1, 3, 6, 12, 24 and 36 mg. The marketed tablet is dosed 0.8, 2.5, 5.5, 9, 14.5 and 17.2 mg. Lilly states these are equivalent, and its 2026 press releases restate the trial results in tablet numbers [3][10].

So when you see a 2025 article headlined “orforglipron 36 mg produced 12.4% weight loss,” it is describing the same exposure as the 17.2 mg Foundayo tablet. The mapping is 1→0.8, 3→2.5, 6→5.5, 12→9, 24→14.5 and 36→17.2 mg. It is the single most common source of confusion for anyone reading the older coverage.

Sources

1. Lilly’s oral GLP-1 orforglipron demonstrated meaningful weight loss (ATTAIN-1 topline) — Eli Lilly, August 7, 2025
2. ATTAIN-1 (NCT05869903) — ClinicalTrials.gov
3. FOUNDAYO US Prescribing Information, revised 7/2026 — Eli Lilly and Company
4. Lilly’s oral GLP-1 orforglipron successful in third Phase 3 trial (ATTAIN-2) — Eli Lilly, August 26, 2025
5. ACHIEVE-3: orforglipron versus oral semaglutide — The Lancet, February 26, 2026
6. ATTAIN-MAINTAIN results — Nature Medicine, May 2026
7. Switching reports in the Foundayo community — r/FoundayoPill, May 29, 2026
8. Orforglipron for obesity treatment in older patients 65 and over — Obesity Pillars, July 14, 2026
9. Lilly’s Foundayo: the only oral GLP-1 taken without food restrictions (ADA 2026 analyses) — Eli Lilly, June 2026
10. ACHIEVE-4, the longest Phase 3 study of Foundayo — Eli Lilly, April 16, 2026
11. ATTAIN-Outcomes (NCT07241390) — ClinicalTrials.gov
12. ATTAIN-1 full publication — New England Journal of Medicine, November 6, 2025
13. Foundayo user reviews — Drugs.com
14. Lilly reports second-quarter 2026 financial results — Eli Lilly and Company, August 5, 2026
15. FOUNDAYO label, NDA 220934 supplement s003, Section 14 Clinical Studies — US Food and Drug Administration