Foundayo Weight Loss Calculator
How much weight do people lose on Foundayo, the daily orforglipron pill? This calculator maps the ATTAIN-1 trial averages onto your starting weight, your dose, and how long you have been taking it.
Free · instant results · no sign-up or email · built on published clinical trial data
−00−24lb
11.1% of body weight
220 lb → 196 lb
Out of 100 people on 17.2 mg
A trial average is not a prediction. Weeks between trial timepoints are estimated. Source: ATTAIN-1, Wharton et al., NEJM 2025
Free · No account required · iPhone
Quick answer: In ATTAIN-1, adults with obesity and without diabetes lost an average of 7.4% of body weight on Foundayo 5.5 mg, 8.3% on 9 mg and 11.1% on 17.2 mg daily over 72 weeks, alongside a reduced-calorie diet and more activity, against 2.1% for diet and exercise alone. For a 220 lb starting weight the top dose works out at roughly 24 lb. The calculator above puts your own starting weight through the same curve, and the free GlucoPal iPhone app tracks daily pills like Foundayo alongside weight, meals, and side effects.
This calculator uses the US label strengths (5.5, 9 and 17.2 mg), which is what your prescription bottle says. News coverage of ATTAIN-1 quotes the investigational trial capsules (12, 24 and 36 mg) instead. Same three arms, two different naming systems.
Educational reference only, not medical advice and not a prediction of individual results. Trial participants used the medication alongside a reduced-calorie diet and increased activity. Talk to your prescriber about what to expect for you.
Why your bottle says 17.2 mg and the news said 36 mg
This is the single most confusing thing about Foundayo, so it is worth clearing up before you read any numbers. ATTAIN-1 dosed participants with investigational capsules described as 12, 24 and 36 mg. The marketed tablets are labelled in free-base equivalents, which come out as 5.5, 9 and 17.2 mg. The FDA label maps the trial arms to those marketed strengths.
So a headline saying "36 mg orforglipron" and a pharmacy bottle saying 17.2 mg are describing the same dose and the same trial arm. Nothing was reduced. We use the label strengths throughout this calculator so the dose you pick matches the dose you are actually prescribed.
Foundayo weight loss by dose and month
ATTAIN-1 (Wharton et al., NEJM 2025) ran for 72 weeks in adults with obesity (BMI 30+, or 27+ with a weight-related condition), without diabetes. Average baseline weight was about 228 lb (103.2 kg), so the 17.2 mg average of 11.1% corresponds to roughly 25 lb for a typical participant.
| Time point | Foundayo 5.5 mg | Foundayo 9 mg | Foundayo 17.2 mg |
|---|---|---|---|
| 3 months (wk 13) | −3.5% | −3.9% | −5.3% |
| 6 months (wk 26) | −5.5% | −6.3% | −8.3% |
| 9 months (wk 39) | −6.5% | −7.4% | −9.8% |
| 12 months (wk 52) | −7.1% | −7.9% | −10.6% |
| 15 months (wk 65) | −7.3% | −8.2% | −11.0% |
| Trial end | −7.4% | −8.3% | −11.1% |
Intermediate months are estimated from the published curve shape and verified anchors; the trials publish week-by-week values only as figures. The trial-end row is the published result.
One caveat that matters more here than on the other calculators: ATTAIN-1 publishes no intermediate timepoints at all, and no curve-shape statements. The monthly rows above are therefore the most loosely anchored of the four medications on this site. They come from a generic saturating weight-loss curve normalised to hit the published 72-week endpoints exactly. Treat the trial-end row as data and the rest as a sketch.
What being a daily pill changes
Foundayo is orforglipron, a small-molecule GLP-1 receptor agonist taken as a tablet once a day. That is a genuinely different routine from a weekly injection: no needles, no fridge, and no pen supply to chase, but also 365 chances a year to forget a dose instead of 52.
The label allows Foundayo to be taken with or without food, which is a practical difference from the oral semaglutide tablet and its food and water timing rules. As with the injectables, the dose is stepped up over time rather than started at the maintenance strength, so your first months sit below the dose the curve is named after.
A daily tablet also changes what is worth logging. With a weekly injection, the record that matters is dose day and side effects across the week. With a daily pill, adherence over a run of days is the thing you actually want to see. GlucoPal is a free iPhone app that tracks daily pills alongside weight, meals, and side effects, with a doctor-ready export for appointments.
How Foundayo compares to the injections
On published trial averages, the injectables are the larger numbers. The top Foundayo arm averaged 11.1% over 72 weeks, against 14.9% for Wegovy 2.4 mg over 68 weeks and 20.9% for tirzepatide 15 mg over 72 weeks. These are three separate trials with different designs and populations, so they are three published averages rather than a head-to-head result, but the ordering is consistent enough to be worth knowing.
The responder spread tells the same story. On 17.2 mg, 71.5% of participants lost at least 5%, 54.5% of participants lost at least 10%, 35.9% of participants lost at least 15%, and 18.4% of participants lost at least 20%.
Which is not the whole decision. A tablet you will actually take beats an injection you will not, and availability, cost, and tolerability all sit alongside the average. That is a conversation for your prescriber, not a number to settle on your own.
What this calculator can and cannot tell you
It is a reference point, not a forecast. The 72-week endpoints and the responder percentages are verified published numbers from the trial and the FDA label. The month-by-month values are estimated, and for Foundayo specifically they are estimated with less to anchor to than for the other three medications, because ATTAIN-1 reports no intermediate timepoints.
Foundayo is also the newest of the four, so there is far less real-world follow-up than for tirzepatide or semaglutide. Longer-term data, plateau timing, and durability of the loss are genuinely less well characterised here. We will update these curves as FDA review documents and further ATTAIN publications become available.
As with every page on this site, this is educational information rather than medical advice, the trial population may not match your situation, and the numbers reflect medication plus a structured diet and activity programme rather than medication alone.
FAQ
How much weight will I lose on Foundayo?
There is no way to predict an individual result. In ATTAIN-1, adults with obesity and without diabetes lost an average of 7.4% on 5.5 mg, 8.3% on 9 mg and 11.1% on 17.2 mg daily over 72 weeks, against 2.1% for diet and exercise alone. For a 220 lb starting weight, the top dose average is roughly 24 lb. Individual results varied widely in both directions.
Is Foundayo 17.2 mg the same as orforglipron 36 mg?
Yes. ATTAIN-1 used investigational capsules described as 12, 24 and 36 mg, while the marketed tablets are labelled in free-base equivalents as 5.5, 9 and 17.2 mg. The FDA label maps the trial arms onto the marketed strengths, so 17.2 mg on your bottle is the arm reported as 36 mg in trial coverage. This calculator uses the label strengths so it matches your prescription.
Is Foundayo as effective as Zepbound or Wegovy?
On published averages, no. The top Foundayo arm averaged 11.1% over 72 weeks, against 14.9% for Wegovy 2.4 mg over 68 weeks and 20.9% for tirzepatide 15 mg over 72 weeks. Those come from three separate trials rather than a head-to-head comparison, so the gap is indicative rather than exact. Foundayo is a daily tablet rather than a weekly injection, which is a real advantage for some people, and the medication you can stick with matters more than the trial average.
Do I take Foundayo with food?
The Foundayo label says it can be taken with or without food, which is a practical difference from oral semaglutide and its food and water timing requirements. Follow the instructions your prescriber and pharmacist give you, and check the prescribing information linked below rather than relying on a general summary.
How accurate are the month-by-month Foundayo numbers?
Less accurate than the equivalent numbers for tirzepatide and semaglutide, and we would rather say so. ATTAIN-1 publishes its 72-week endpoints but no intermediate timepoints and no curve-shape statements, and the FDA review documents were not yet public when these curves were built. The monthly values come from a generic saturating weight-loss curve normalised to hit the published endpoints exactly. The trial-end row is data; the months before it are an estimate of the shape.
Is this calculator free, and do I need to sign up?
Yes, it is free, and no sign-up or email is required. You see the full result instantly: the trial average for your starting weight, the month-by-month curve, and the responder milestones. The GlucoPal iOS app it comes from is also free to download.
Other medications
Zepbound weight loss calculator
Tirzepatide, 20.9% average on 15 mg over 72 weeks in SURMOUNT-1.
Wegovy weight loss calculator
All three forms: the 2.4 mg injection, Wegovy HD 7.2 mg, and the 25 mg daily tablet.
GLP-1 pill calculator
Foundayo against the Wegovy 25 mg tablet, the only other approved weight-loss pill.
Compare all four medications
Every trial average side by side in one table.
Who built this calculator
This free calculator is built and maintained by GlucoPal, the team behind the free GLP-1 Tracker by GlucoPal iPhone app, rated 4.8 stars from 4,000+ App Store ratings and used by 100,000+ people. The calculator runs entirely in your browser and stores no health data.
Sources
You take your GLP-1s.
We'll take care of the rest.
Free · No account required · Tracking in under 30 seconds