Wegovy's trials recorded an average weight loss of about 10% to 19% depending on the dose and the population, against 2% to 6% on placebo. The highest averages come from the 7.2 mg dose and from a trial that paired the drug with an intensive diet programme; the lowest from people with type 2 diabetes. Each trial below is reported with who was in it, how long it ran and what its number counts.
Every trial result comes from the WEGOVY prescribing information (SPL effective 18 June 2026, version 19), section 14, or from the trial's own publication where the label does not carry it, all read on 20 October 2026. The label numbers its studies; the trial names (STEP, OASIS) are the ones used in publications and in most searches, and both are given. Kilogram conversions are glp1ledger's arithmetic and are marked. What Wegovy is approved for and how it is sold is on what is Wegovy; this page is the outcomes.
The trials on the label
| Trial (label study) | Who | Weeks | Wegovy | Placebo |
|---|---|---|---|---|
| STEP 1 (Study 2) | 1,961 adults, obesity or overweight with a condition, no diabetes | 68 | -14.9% (2.4 mg) | -2.4% |
| STEP 2 (Study 3) | 807 adults with type 2 diabetes | 68 | -9.6% (2.4 mg) | -3.4% |
| STEP 3 (Study 4) | 611 adults on intensive behavioural therapy, starting with an 8-week low-calorie diet | 68 | -16.0% (2.4 mg) | -5.7% |
| STEP 4 (Study 5) | 803 adults who reached 2.4 mg in a 20-week run-in | 20 → 68 | -7.9% further | +6.9% (switched to placebo) |
| STEP 6 (Study 6) | 401 adults in Japan and South Korea | 68 | -9.6% (1.7 mg) · -13.2% (2.4 mg) | -2.1% |
| OASIS 4 (Study 7) | 307 adults, 25 mg tablet | 64 | -13.6% | -2.4% |
| STEP UP (Study 8) | 1,407 adults with obesity | 72 | -15.5% (2.4 mg) · -18.8% (7.2 mg) | -3.9% |
| STEP UP T2D (Study 9) | 512 adults with obesity and type 2 diabetes | 72 | -10.4% (2.4 mg) · -13.2% (7.2 mg) | -3.8% |
| STEP TEENS (Study 10) | 201 adolescents aged 12+ | 68 | -14.7% body weight; BMI -16.1% | +2.7%; BMI +0.6% |
Least-squares mean percent change from baseline, intention-to-treat population. Label Tables 8 to 12 and 18.
What the label's numbers count. All randomised people are in them, including those who stopped taking the drug — 16% of Wegovy-treated people across STEP 1 to 3, and 18% on the tablet in OASIS 4. Where a final weight was missing, it was imputed from people in the same arm who had stopped but kept coming to visits (the label calls this retrieved-dropout multiple imputation). That makes the label's figures closer to "what happened to everyone assigned to Wegovy" than to "what happened to people who took every dose". Publications of the same trials often also report a second, larger figure for people who stayed on treatment; the two should not be mixed in one comparison.
The same results in kilograms
The label reports percentages. glp1ledger multiplied each arm's reported baseline weight by its mean percent change, so these are approximations of the average, not measured kilograms:
| Trial and arm | Baseline weight | Mean change | About |
|---|---|---|---|
| STEP 1, placebo | 105.2 kg | -2.4% | 2.5 kg |
| STEP 1, 2.4 mg | 105.4 kg | -14.9% | 15.7 kg |
| STEP 2, 2.4 mg (type 2 diabetes) | 99.9 kg | -9.6% | 9.6 kg |
| STEP 3, 2.4 mg (with intensive programme) | 106.9 kg | -16.0% | 17.1 kg |
| OASIS 4, 25 mg tablet | 106.4 kg | -13.6% | 14.5 kg |
| STEP UP, 2.4 mg | 116.5 kg | -15.5% | 18.1 kg |
| STEP UP, 7.2 mg | 112.4 kg | -18.8% | 21.1 kg |
STEP UP's participants started heavier than STEP 1's (a mean of 113 kg across the trial against 105 kg), so its kilogram figures are larger partly because its people were.
How many people reached each milestone
| Lost at least | STEP 1 placebo | STEP 1, 2.4 mg | STEP 2, 2.4 mg (diabetes) | STEP UP, 2.4 mg | STEP UP, 7.2 mg |
|---|---|---|---|---|---|
| 5% | 31.1% | 83.5% | 67.4% | 86.6% | 88.7% |
| 10% | 12.0% | 66.1% | 44.5% | 72.0% | 79.8% |
| 15% | 4.8% | 47.9% | 25.1% | 52.3% | 63.8% |
| 20% | 1.7% | 30.2% | 12.8% | 32.3% | 45.5% |
Label Tables 8 and 12. The 20% row was not part of STEP 1's pre-specified testing, and STEP UP's 2.4 mg figures were reported "for informative purposes", as the label's footnotes state.
Turned around, the STEP 1 column says that about one person in six on 2.4 mg did not lose 5% and seven in ten did not reach 20%. On 7.2 mg, a little over one in ten did not reach 5%. The label gives no way to tell in advance which group a person will fall into; it reports the distribution only. Why some people stop losing and what the trials recorded about it is on GLP-1 plateau.
Four trials that answer narrower questions
STEP 3 asked what the drug adds to an intensive programme. Participants started with eight weeks on a 1,000 to 1,200 kcal diet and then received intensive behavioural therapy throughout. The placebo group lost 5.7%, the most of any placebo arm here, and the Wegovy group 16.0%. The gap between the two (10.3 points) is smaller than STEP 1's (12.4) because the programme moved the placebo arm, not because the drug did less.
STEP 4 asked what happens when it is withdrawn. Everyone took Wegovy for 20 weeks first; 99 of 902 (11%) stopped before randomisation, 48 of them because of side effects. The 803 who reached 2.4 mg had fallen from an average of 107.2 kg to about 96 kg. Over the next 48 weeks, those kept on Wegovy lost a further 7.9% while those switched to placebo regained 6.9% — by glp1ledger's arithmetic, ending near 89 kg and 102 kg. The label adds a caution worth repeating: because people who could not tolerate the dose were excluded before randomisation, the result "may not reflect the experience" of people starting Wegovy for the first time.
STEP 5 asked whether the loss holds for two years. In 304 adults without diabetes, the 104-week change was -15.2% against -2.6% on placebo, and 77.1% against 34.4% had lost at least 5% (Garvey et al., Nature Medicine 2022). That is close to STEP 1's 68-week figure, so on average the loss reached at about a year and a half was maintained to two years in people who stayed in the trial.
STEP 8 asked how it compares with the older daily drug. In 338 adults, an open-label 68-week trial recorded -15.8% on semaglutide 2.4 mg against -6.4% on liraglutide 3.0 mg (Saxenda's dose) and -1.9% on pooled placebo; 38.5% against 6.0% reached a 20% loss (Rubino et al., JAMA 2022). The two medicines are compared label by label on semaglutide vs liraglutide.
The longest follow-up: four years in SELECT
SELECT was a cardiovascular-outcomes trial in 17,604 adults with heart disease and overweight or obesity but no diabetes, so weight was a secondary measure. The label reports -9.43 kg on Wegovy against -0.93 kg on placebo at 104 weeks (Table 7, from a baseline of about 96.5 kg). A pre-specified analysis published in 2024 reported -10.2% against -1.5% at 208 weeks — four years — with waist circumference down 7.7 cm against 1.3 cm (Ryan et al., Nature Medicine 2024). SELECT's people were older and had established heart disease, and its weight figures are lower than STEP 1's; it was not designed as a weight trial. Its heart results are on what is Wegovy.
After stopping
The STEP 1 extension followed 327 participants for a year after treatment ended at week 68. Those who had been on semaglutide had lost 17.3% by week 68 (this subgroup lost more than the trial average) and had regained 11.6 percentage points by week 120, a net loss of 5.6%; those on placebo regained 1.9 points, a net 0.1%. Blood pressure, blood lipids and blood sugar, which had improved on treatment, moved back towards their starting values for most measures (Wilding et al., Diabetes, Obesity and Metabolism 2022). Together with STEP 4, it is the reason the label describes the indication as weight reduction and long-term maintenance. What else is known about stopping is on stopping GLP-1 drugs.
What these results do not tell you
- Individual results. The trials report averages and thresholds, not a prediction for any one person.
- Results outside a trial. Trial participants had scheduled visits, diet counselling and a fixed escalation; most also received a target of about 500 kcal a day below their needs and 150 minutes of activity a week.
- Muscle versus fat. The label reports weight and waist only; body composition is on muscle loss.
- A head-to-head with Zepbound beyond one trial. The only one, SURMOUNT-5, is on Zepbound vs Wegovy; Zepbound's own trial record is on Zepbound weight loss results.
The doses named here are the doses the trials tested, reported as results. Whether Wegovy, or which dose, suits a particular person is a decision for that person and their prescriber. The side effects recorded in the same trials are on Wegovy side effects.
Sources
- Novo Nordisk, WEGOVY (semaglutide) injection and tablets, prescribing information, SPL effective 2026-06-18, version 19, DailyMed set ee06186f-2aa3-4990-a760-757579d8f77b: section 14, Tables 7 to 12 and 18 — read 2026-10-20.
- Garvey WT et al. "Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial." Nat Med 2022;28:2083-2091, PubMed 36216945.
- Rubino DM et al. "Effect of Weekly Subcutaneous Semaglutide vs Daily Liraglutide on Body Weight in Adults With Overweight or Obesity Without Diabetes: The STEP 8 Randomized Clinical Trial." JAMA 2022;327:138-150, PubMed 35015037.
- Wilding JPH et al. "Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension." Diabetes Obes Metab 2022;24:1553-1564, PubMed 35441470.
- Ryan DH et al. "Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial." Nat Med 2024;30:2049-2057, PubMed 38740993.
- Wharton S et al. "Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial." Lancet Diabetes Endocrinol 2025;13:949-963, PubMed 40961952.