When a GLP-1 doesn't work: what the FDA labels show
Last updated
In each FDA label's main trial, some people did not lose even 5% of their weight: Zepbound 15 mg, 9.1% (SURMOUNT-1, week 72); Wegovy 2.4 mg injection, 16.5% (Study 2, week 68); Wegovy 25 mg tablet, 23.7% (OASIS 4, week 64); Foundayo 17.2 mg, 28.5% (ATTAIN-1, week 72); Saxenda, 37.7% (Study 1, week 56). On placebo, 65.5% to 73.2% did not. These are separate trials in different people, so they do not rank the medicines. Only Saxenda's label sets a point to stop: "Evaluate the change in body weight 16 weeks after initiating SAXENDA and discontinue SAXENDA if the patient has not lost at least 4% of baseline body weight, since it is unlikely that the patient will achieve and sustain clinically meaningful weight loss with continued treatment."
How many lost 5%, 10%, 15% and 20%
Every row each label prints, by trial and dose. The last column is 100 minus the label's 5% figure.
Wegovy
“Table 8. Changes in Body Weight at Week 68 in Studies 2, 3, and 4 with WEGOVY 2.4 mg Injection”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| Study 2, placeboWeek 68 | 655 | 31.1% | 12% | 4.8% | 1.7% | 68.9% |
| Study 2, Wegovy 2.4 mg injectionWeek 68 | 1,306 | 83.5% | 66.1% | 47.9% | 30.2% | 16.5% |
| Study 3, placeboWeek 68 | 403 | 30.2% | 10.2% | 4.3% | 2.3% | 69.8% |
| Study 3, Wegovy 2.4 mg injectionWeek 68 | 404 | 67.4% | 44.5% | 25.1% | 12.8% | 32.6% |
| Study 4, placeboWeek 68 | 204 | 47.8% | 27.1% | 13.2% | 3.5% | 52.2% |
| Study 4, Wegovy 2.4 mg injectionWeek 68 | 407 | 84.8% | 73% | 53.4% | 33.9% | 15.2% |
“Table 10. Changes in Body Weight at Week 68 in Study 6 in East-Asian Patients with WEGOVY 1.7 and 2.4 mg Injection”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| STEP 6 (Study 6), placeboWeek 68 | 101 | 19.4% | 4.5% | 2.6% | 80.6% | |
| STEP 6 (Study 6), Wegovy 1.7 mg injectionWeek 68 | 101 | 72.8% | 39.1% | 20.8% | 27.2% | |
| STEP 6 (Study 6), Wegovy 2.4 mg injectionWeek 68 | 199 | 84% | 59.9% | 38.2% | 16% |
“Table 11. Changes in Body Weight at Week 64 in Study 7 with WEGOVY 25 mg Tablets”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| OASIS 4 (Study 7), placeboWeek 64 | 102 | 31.3% | 14.4% | 5.5% | 3.1% | 68.7% |
| OASIS 4 (Study 7), Wegovy 25 mg tabletWeek 64 | 205 | 76.3% | 59.8% | 47% | 27.9% | 23.7% |
“Table 12. Changes in Body Weight at Week 72 in Studies 8 and 9 with WEGOVY 7.2 mg Injection”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| STEP UP (Study 8), placeboWeek 72 | 201 | 38.3% | 20.3% | 7.5% | 2.8% | 61.7% |
| STEP UP (Study 8), Wegovy 2.4 mg injectionWeek 72 | 201 | 86.6% | 72% | 52.3% | 32.3% | 13.4% |
| STEP UP (Study 8), Wegovy 7.2 mg injectionWeek 72 | 1,005 | 88.7% | 79.8% | 63.8% | 45.5% | 11.3% |
| Study 9, placeboWeek 72 | 102 | 34% | 11.2% | 6.9% | 2% | 66% |
| Study 9, Wegovy 2.4 mg injectionWeek 72 | 103 | 74% | 49.5% | 27% | 13.5% | 26% |
| Study 9, Wegovy 7.2 mg injectionWeek 72 | 307 | 83.7% | 60.7% | 39.8% | 20.6% | 16.3% |
Zepbound
“Table 2: Changes in Body Weight at Week 72 in Studies 1 and 2 in Patients with Obesity or Overweight”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| SURMOUNT-1 (Study 1), placeboWeek 72 | 643 | 34.5% | 18.8% | 8.8% | 3.1% | 65.5% |
| SURMOUNT-1 (Study 1), Zepbound 5 mgWeek 72 | 630 | 85.1% | 68.5% | 48% | 30% | 14.9% |
| SURMOUNT-1 (Study 1), Zepbound 10 mgWeek 72 | 636 | 88.9% | 78.1% | 66.6% | 50.1% | 11.1% |
| SURMOUNT-1 (Study 1), Zepbound 15 mgWeek 72 | 630 | 90.9% | 83.5% | 70.6% | 56.7% | 9.1% |
| SURMOUNT-2 (Study 2), placeboWeek 72 | 315 | 32.5% | 9.5% | 2.7% | 1% | 67.5% |
| SURMOUNT-2 (Study 2), Zepbound 10 mgWeek 72 | 312 | 79.2% | 60.5% | 39.7% | 21.5% | 20.8% |
| SURMOUNT-2 (Study 2), Zepbound 15 mgWeek 72 | 311 | 82.8% | 64.8% | 48% | 30.8% | 17.2% |
“Table 4: Changes in Body Weight After 12-Week Intensive Lifestyle Intervention Lead-In Followed by Randomized Treatment and a Standard Lifestyle Intervention (Study 3) in Patients with Obesity or Overweight”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| SURMOUNT-3 (Study 3), placeboWeek 72 | 292 | 16.5% | 8.9% | 4.2% | 2.2% | 83.5% |
| SURMOUNT-3 (Study 3), Zepbound MTD (10 mg or 15 mg)Week 72 | 287 | 87.5% | 76.7% | 65.4% | 44.7% | 12.5% |
Foundayo
“Table 6: Changes from Baseline in Body Weight at Week 72 in Trials 1 and 2 in Patients with Obesity or Overweight with ≥1 Weight-related Comorbid Condition”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| ATTAIN-1 (Trial 1), placeboWeek 72 | 949 | 26.8% | 13% | 6% | 2.9% | 73.2% |
| ATTAIN-1 (Trial 1), Foundayo 5.5 mgWeek 72 | 723 | 59.6% | 32.5% | 14.3% | 5.9% | 40.4% |
| ATTAIN-1 (Trial 1), Foundayo 9 mgWeek 72 | 725 | 63.1% | 39.8% | 20.1% | 8.9% | 36.9% |
| ATTAIN-1 (Trial 1), Foundayo 17.2 mgWeek 72 | 730 | 71.5% | 54.5% | 35.9% | 18.4% | 28.5% |
| ATTAIN-2 (Trial 2), placeboWeek 72 | 630 | 26.8% | 9.2% | 3.1% | 0.7% | 73.2% |
| ATTAIN-2 (Trial 2), Foundayo 5.5 mgWeek 72 | 329 | 47.4% | 22.5% | 6.7% | 2.6% | 52.6% |
| ATTAIN-2 (Trial 2), Foundayo 9 mgWeek 72 | 332 | 54.7% | 31.1% | 14.4% | 4.4% | 45.3% |
| ATTAIN-2 (Trial 2), Foundayo 17.2 mgWeek 72 | 322 | 67% | 45.6% | 25.9% | 10.8% | 33% |
Saxenda
“Table 4. Changes in Weight at Week 56 for Studies 1, 2, and 3”
| Trial and arm | People | Lost 5%+ | 10%+ | 15%+ | 20%+ | Under 5% |
|---|---|---|---|---|---|---|
| Study 1, SaxendaWeek 56 | 2,487 | 62.3% | 33.9% | 37.7% | ||
| Study 1, placeboWeek 56 | 1,244 | 34.4% | 15.4% | 65.6% | ||
| Study 2, SaxendaWeek 56 | 423 | 49% | 22.4% | 51% | ||
| Study 2, placeboWeek 56 | 212 | 16.4% | 5.5% | 83.6% | ||
| Study 3, SaxendaWeek 56 | 212 | 44.2% | 25.4% | 55.8% | ||
| Study 3, placeboWeek 56 | 210 | 21.7% | 6.9% | 78.3% |
When a label says to stop
Saxenda: “Evaluate the change in body weight 16 weeks after initiating SAXENDA and discontinue SAXENDA if the patient has not lost at least 4% of baseline body weight, since it is unlikely that the patient will achieve and sustain clinically meaningful weight loss with continued treatment.” FDA label
The other labels on this page set no such point. How soon each one reaches its full dose is on how long GLP-1s take to work.
Separate trials, not a ranking
Each label's figures come from its own trials, in different people over different lengths of time, so a higher share on one label does not show that medicine works better. A fair comparison is a trial that gave two of them to the same kind of people at the same time, such as SURMOUNT-5, Wegovy injection against Zepbound.
Common questions
Why isn't Zepbound working for me?
We cannot say why for you; your prescriber can. What Zepbound's FDA label shows is that it did not work for everyone in its own trial. On Zepbound 15 mg, 90.9% lost at least 5% of their weight by week 72 in SURMOUNT-1, against 34.5% on placebo, so 9.1% did not. Label effective Aug 28, 2026.
Why isn't Wegovy working for me?
We cannot say why for you; your prescriber can. What Wegovy's FDA label shows is that it did not work for everyone in its own trial. On Wegovy 2.4 mg injection, 83.5% lost at least 5% of their weight by week 68 in Study 2, against 31.1% on placebo, so 16.5% did not. Label effective Jun 18, 2026.
Why isn't the Wegovy pill working?
We cannot say why for you; your prescriber can. What Wegovy's FDA label shows is that it did not work for everyone in its own tablet trial. On Wegovy 25 mg tablet, 76.3% lost at least 5% of their weight by week 64 in OASIS 4, against 31.3% on placebo, so 23.7% did not. Label effective Jun 18, 2026.
Why isn't Foundayo working for me?
We cannot say why for you; your prescriber can. What Foundayo's FDA label shows is that it did not work for everyone in its own trial. On Foundayo 17.2 mg, 71.5% lost at least 5% of their weight by week 72 in ATTAIN-1, against 26.8% on placebo, so 28.5% did not. Label effective Jul 29, 2026.
Why isn't Saxenda working for me?
We cannot say why for you; your prescriber can. What Saxenda's FDA label shows is that it did not work for everyone in its own trial. On Saxenda, 62.3% lost at least 5% of their weight by week 56 in Study 1, against 34.4% on placebo, so 37.7% did not. Label effective Feb 25, 2026.
Does a higher dose work better?
In the trials that tested more than one dose, the share losing at least 5% rose with the dose: Wegovy, STEP 6: 1.7 mg injection 72.8%, 2.4 mg injection 84%; Wegovy, STEP UP: 2.4 mg injection 86.6%, 7.2 mg injection 88.7%; Wegovy, Study 9: 2.4 mg injection 74%, 7.2 mg injection 83.7%; Zepbound, SURMOUNT-1: 5 mg 85.1%, 10 mg 88.9%, 15 mg 90.9%; Zepbound, SURMOUNT-2: 10 mg 79.2%, 15 mg 82.8%; Foundayo, ATTAIN-1: 5.5 mg 59.6%, 9 mg 63.1%, 17.2 mg 71.5%; Foundayo, ATTAIN-2: 5.5 mg 47.4%, 9 mg 54.7%, 17.2 mg 67%. Whether to raise your dose is your prescriber's call.
How long before you know a GLP-1 is not working?
Saxenda's label: "Evaluate the change in body weight 16 weeks after initiating SAXENDA and discontinue SAXENDA if the patient has not lost at least 4% of baseline body weight, since it is unlikely that the patient will achieve and sustain clinically meaningful weight loss with continued treatment." The other labels set no such point; their trials measured weight at week 64, 68, or 72.