Foundayo results: what the trials show
Foundayo (orforglipron) was tested in the 72-week ATTAIN-1 trial of 3,127 adults. This guide gives the weight loss figures for each dose, the share of people reaching 5%, 10% and 15%, and a plain comparison with Mounjaro, Wegovy and the Wegovy pill.
In short: In the ATTAIN-1 trial, adults taking the dose matching the 17.2 mg Foundayo tablet lost an average of 11.2% of body weight over 72 weeks, counting everyone who started. The figure was 12.4% for people who stayed on treatment. Placebo gave 2.1% and 0.9%. Lower doses gave 7.5% to 9.3%. All groups received diet and activity support. Results vary from person to person and are never guaranteed.
ATTAIN-1 results by dose #
ATTAIN-1 enrolled 3,127 adults with obesity, or overweight with a weight-related condition, and without diabetes. The average starting weight was 103.2 kg. Participants took a daily capsule or placebo for 72 weeks alongside a healthy diet and physical activity. The capsule doses of 6 mg, 12 mg and 36 mg match the 5.5 mg, 9 mg and 17.2 mg tablets.
The published results give two averages for each dose. The first counts every participant, including people who stopped the medicine early. The second estimates the result for people who stayed on treatment for the full 72 weeks.
| Tablet dose (trial capsule) | All participants | Stayed on treatment | Average kg lost, on treatment |
|---|---|---|---|
| 5.5 mg (6 mg) | 7.5% | 7.8% | 8.0 kg |
| 9 mg (12 mg) | 8.4% | 9.3% | 9.4 kg |
| 17.2 mg (36 mg) | 11.2% | 12.4% | 12.4 kg |
| Placebo | 2.1% | 0.9% | 1.0 kg |
Share of people reaching 5%, 10%, 15% and 20% #
Averages hide the spread, so the trial also counted how many people passed set milestones. The figures below are the on-treatment estimates reported in the UK product information.
| Weight loss | 5.5 mg dose | 9 mg dose | 17.2 mg dose | Placebo |
|---|---|---|---|---|
| 5% or more | 63.8% | 69.3% | 77.1% | 22.1% |
| 10% or more | 35.9% | 45.1% | 59.6% | 8.6% |
| 15% or more | 16.5% | 24.0% | 39.6% | 3.6% |
| 20% or more | 7.2% | 11.4% | 20.1% | 1.6% |
Counting every participant, 54.6% on the top dose lost 10% or more, 36.0% lost 15% or more and 18.4% lost 20% or more. About 23% of people on the top dose did not reach a 5% loss.
A month-by-month expectation #
The sources behind this page report weight at week 72 only, so no verified month-by-month weight figures exist to quote. What the product information does fix is the dose schedule, and the schedule shapes the pace.
| Period | Dose | What to expect |
|---|---|---|
| Month 1 | 0.8 mg | Introductory strength. Your body adjusts. Appetite changes may be small. |
| Month 2 | 2.5 mg | Second introductory strength. Gut side effects may appear after the increase. |
| Month 3 | 5.5 mg | First strength with 72-week trial data. Average loss on this dose reached 7.5% to 7.8% by week 72. |
| Month 6 to month 17 | Your settled dose | Trial results were measured at week 72, about 17 months after starting. |
What slows results #
- Staying on a low strength. Average loss rose with dose, from 7.5% on the 5.5 mg dose to 11.2% on the 17.2 mg dose. A lower strength is still the right choice when side effects limit you.
- Stopping early. Between 5.3% and 10.3% of people on Foundayo stopped because of side effects, which is why the all-participant averages are lower.
- Type 2 diabetes. In ATTAIN-2, adults with type 2 diabetes lost an average of 10.5% on the top dose at 72 weeks, against 12.4% in ATTAIN-1.
- Interacting medicines. Carbamazepine cut orforglipron exposure by 82% in testing. Rifampicin, phenytoin and St John's wort are to be avoided for the same reason.
- Diet and activity. Every ATTAIN-1 participant received diet and activity support, so the trial figures include the effect of both.
The weight loss plateau guide covers the parts you control. The Foundayo doses guide explains when moving up a strength makes sense.
How Foundayo compares with the other three medicines #
No trial has compared Foundayo head to head with Mounjaro, Wegovy injections or the Wegovy pill at weight management doses. The table places the main trial for each medicine side by side. Each figure counts all participants and came alongside diet and activity support. The trials differ in length, size and participants, so treat the gaps as a rough guide.
| Medicine and dose | Trial | Length | Average loss | Placebo |
|---|---|---|---|---|
| Foundayo 17.2 mg daily tablet | ATTAIN-1 | 72 weeks | 11.2% | 2.1% |
| Wegovy pill 25 mg daily tablet | OASIS 4 | 64 weeks | 13.6% | 2.2% |
| Wegovy 2.4 mg weekly injection | STEP 1 | 68 weeks | 14.9% | 2.4% |
| Wegovy 7.2 mg weekly injection | STEP UP | 72 weeks | 18.7% | 3.9% |
| Mounjaro 5 mg weekly injection | SURMOUNT-1 | 72 weeks | 15.0% | 3.1% |
| Mounjaro 10 mg weekly injection | SURMOUNT-1 | 72 weeks | 19.5% | 3.1% |
| Mounjaro 15 mg weekly injection | SURMOUNT-1 | 72 weeks | 20.9% | 3.1% |
In plain numbers, the injections produced larger average losses, and Foundayo offers the simplest daily routine of the four. OASIS 4 enrolled 307 people, against 3,127 in ATTAIN-1. Read the detailed comparisons on Foundayo vs the Wegovy pill, Foundayo vs Mounjaro and pills vs pens.
What Foundayo has not been shown to do #
- Prevent heart attacks or strokes. ATTAIN-1 measured weight, waist, blood pressure, blood fats and blood sugar. The trial was not designed to count heart attacks or strokes.
- Keep weight off after you stop. ATTAIN-1 reported results while people were taking the medicine.
- Work beyond 72 weeks. The main weight management trials ran for 72 weeks.
- Match the injections. No head-to-head weight management trial against Mounjaro or Wegovy has reported.
- Help people under 18. Foundayo has not been studied in this age group.
Foundayo is licensed for weight loss and weight maintenance alongside a reduced-calorie diet and increased activity. Aero Clinic includes maintenance planning, and the weight loss maintenance guide explains the options once you reach your goal. Foundayo is not available on the NHS at present. Aero’s prices are not yet confirmed.
Foundayo results: what the trials show: questions #
How much weight can you lose on Foundayo?
Aero’s treatment prices are not yet confirmed. Before paying, ask for the total price, pack quantity, prescribing fees, dispensing and delivery charges, and follow-up costs. Use your provider’s written quote in the cost planner.
How quickly does Foundayo work?
Progress develops over months and varies between people. The initial 0.8 mg and 2.5 mg steps each last at least 30 days. ATTAIN-1 assessed outcomes at 72 weeks, so its final averages do not predict the first month’s result.
Is Foundayo as effective as Mounjaro?
No head-to-head trial exists. In separate 72-week trials, the top Foundayo dose gave an average loss of 11.2% in ATTAIN-1, and Mounjaro gave 15.0% at 5 mg, 19.5% at 10 mg and 20.9% at 15 mg in SURMOUNT-1. Both sets of figures count all participants and came with diet and activity support.
What percentage of people lose 10% on Foundayo?
ATTAIN-1 reported 59.6% in its on-treatment analysis at the highest dose. Counting every participant, 54.6% lost at least 10% by week 72. These figures concern the dose matching the 17.2 mg tablet; the corresponding placebo results were 8.6% and 12.9%.
Do Foundayo results last after stopping?
ATTAIN-1 does not establish what happens after treatment stops. It measured outcomes during treatment. Discuss the evidence, ongoing benefits, side effects and a longer-term plan with your prescriber before deciding whether to continue, change or stop taking Foundayo.
Foundayo pill plan price to be confirmed
Aero’s treatment prices and service inclusions will be confirmed before booking opens. Ask which prescribing, dispensing, delivery and follow-up costs are included in your quote.
Page information
- Summary
- In ATTAIN-1, the top Foundayo dose led to an average 11.2% to 12.4% weight loss at 72 weeks. See results by dose and how other medicines compare.
- Publisher
- Aero Clinic, operated by AERO HEALTHCARE LTD.
- Editorial update
- Clinical review
- Pending. An editorial update is not a clinical sign-off.
Cite as: Foundayo results: what the trials show, Aero Clinic (https://www.cagri.co.uk), AERO HEALTHCARE LTD. https://www.cagri.co.uk/foundayo-results. Editorial update: 4 November 2026. Clinical review pending.