Wegovy Average Weight Loss: Clinical Trial Results
Nearly three-quarters of American adults are overweight or obese, according to the Centers for Disease Control and Prevention. Yet, until recently, there weren’t many safe and effective medications available to help people with chronic weight management.
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Wegovy is an FDA-approved weight loss medication. Manufactured by Novo Nordisk as Ozempic since 2017, semaglutide, generic for Wegovy, was approved for weight management in June 2021.
So how much weight can you actually lose taking Wegovy? To find the answer, you need to look at the data from the Wegovy research clinical trials.
Wegovy Clinical Trials
The FDA-approved Wegovy based on the outcomes of the Semaglutide Treatment Effect in People with Obesity (STEP) clinical trial.
The initial STEP series consisted of four 68-week, randomized, double-blind clinical trials that enrolled approximately 4,500 people who were overweight or obese. Three of the trials were placebo-controlled, and one was a placebo-withdrawal trial.
Randomized, double-blind, placebo-controlled clinical trials are considered the gold standard for testing.
Clinical trials start with testing a medication’s safety, then its effectiveness, ideal doses, and length of treatment. Finally, the drug may be tested in specific populations. There are currently 236 studies registered on clinicaltrials.gov that mention semaglutide.
STEP 1 Wegovy Research Clinical Trial
STEP 1 Wegovy clinical trial enrolled 1961 participants with a body mass index of 30 or greater or a body mass index (BMI) of 27 or greater with at least one weight-related medical condition other than diabetes. Of those, 1,306 received semaglutide 2.4 mg by subcutaneous injection weekly, and 655 received placebo by subcutaneous injection. The primary endpoint for the trial was greater than 5% weight loss. 86.4% of people receiving semaglutide experienced over 5% weight loss during the in-trial observation period, compared with 31.1% of the placebo group. During the on-treatment observation period, 92.4% achieved an average weight loss of at least 5% body weight on Wegovy. Over 68 weeks of treatment and lifestyle modification, participants had an average 14.9% reduction in body weight, compared with a 2.4% reduction in body weight in the group receiving placebo plus lifestyle modifications. Approximately 70% of participants achieved a weight loss of at least 10%.
| Dosage | Percent body weight reductions | Percent achieving at least 5% reduction in body weight | Percent achieving at least 10% reduction in body weight | Percent achieving at least 15% reduction in body weight |
|---|---|---|---|---|
| 2.4 mg semaglutide | 14.9% | 86.4% | 69.1% | 50.5% |
| placebo | 2.4% | 31.5% | 12.0% | 4.9% |
“Our trial showed that among adults with overweight or obesity (without diabetes), once-weekly subcutaneous semaglutide plus lifestyle intervention was associated with substantial, sustained, clinically relevant mean weight loss of 14.9%, with 86% of participants attaining at least 5% weight loss.”
John P.H. Wilding, D.M., lead author, The New England Journal of Medicine
The STEP 1 extension trial found that the 327 enrolled participants regained approximately two-thirds of their weight loss when they stopped taking semaglutide. Body weight was still at least 5% below what it was at the beginning of the trial, showing there were some long-term benefits. These results also support the premise that obesity is a chronic disease that requires long-term treatment.
STEP 2 Wegovy Research Clinical Trial
The STEP 2 Wegovy weight loss clinical trial enrolled 1,210 participants with type 2 diabetes mellitus who were either overweight or obese. The goal of the clinical trial was to test the standard 1.0 mg dose versus the 2.4 mg dose for over 68 weeks. Medication use was supplemented with lifestyle modification and counseling.
Ozempic (semaglutide) is administered in a 1 mg dose to lower blood sugar and A1C in people with type 2 diabetes. Novo Nordisk sought a separate medical indication for weight loss at a higher dose.
| Dosage | Percent body weight reductions | Percent achieving at least 5% reduction in body weight | Percent achieving at least 10% reduction in body weight | Percent achieving at least 15% reduction in body weight |
|---|---|---|---|---|
| 2.4 mg semaglutide | 9.64% | 68.8% | 45.6% | 25.8% |
| 1.0 mg semaglutide | 6.99% | 57.1% | 28.7% | 13.7% |
| placebo | 3.42% | 28.5% | 8.2% | 3.2% |
Most weight losses occurred in the first 36 weeks. The most common side effects reported were gastrointestinal. According to Lldiko Linvay, study author, average weight loss was lower in STEP 2 than in STEP 1 because people with diabetes typically have a harder time losing weight. However, the weight loss in this study is twice as high as in other medications.
STEP 3 Wegovy Research Clinical Trial
The STEP 3 Wegovy clinical trial enrolled 611 participants who were overweight or obese and related comorbidities but not diabetes. Researchers questioned whether intensive behavioral therapy was needed to achieve weight loss when using semaglutide.
Participants:
- Consumed a low-calorie (1,000–1,200 kcal/day) meal-replacement diet for the first eight weeks
- Consumed a 1,200–1,800 kcal/day diet for the remaining 60 weeks of the trial
- Set an exercise goal of 200 minutes/week
- Received 30 individual intensive behavioral therapy sessions with a dietician
Of the participants, 407 were randomly chosen to receive weekly 2.4 mg semaglutide injections.
| Dosage | Percent body weight reductions | Percent achieving at least 5% reduction in body weight | Percent achieving at least 10% reduction in body weight | Percent achieving at least 15% reduction in body weight |
|---|---|---|---|---|
| 2.4 mg semaglutide | 16.0% | 86.6% | 73.3% | 55.8% |
| placebo | 5.7% | 47.6% | 27.0% | 13.2% |
Weight loss using semaglutide was about double to triple that of other currently approved weight loss medications, according to Thomas Wadden, lead author of the study published in JAMA. These results were similar to those of the STEP 1 clinical trial, which suggests that intensive behavioral therapy may not be needed. However, it is still critical to engage in physical activity because it has benefits to the cardiovascular system that go beyond weight loss alone.
“These findings suggest that the inclusion of intensive behavioral therapy plus an 8-week low-calorie diet ultimately may not contribute to significant additional weight loss beyond that achieved by semaglutide and less-intensive lifestyle intervention.”
Thomas Wadden and co-researchers
STEP 4 Wegovy Research Clinical Trial
The STEP 4 Wegovy clinical trial enrolled 902 participants with overweight or obesity and comorbidities, but not diabetes. Participants all received semaglutide 2.4 mg for the first 20 weeks. Then, for the next 48 weeks, they were randomly assigned to receive either semaglutide or placebo. Researchers were trying to determine whether continuing semaglutide influenced weight loss.
Results show that people who continue on semaglutide lose weight, whereas those who stop taking the medication are more likely to gradually regain their lost weight. By the end of the trial, participants who stayed on semaglutide lost an average of 18.5% of their body weight. Participants who switched to placebo after 20 weeks on semaglutide regained 6.9% of their body weight, for a final weight loss of 3.7%.
| Dosage | Percent body weight reduction |
|---|---|
| 2.4 mg semaglutide for 20 weeks (all participants) | 10.6% |
| 2.4 mg semaglutide for additional 48 weeks | 10.6% + 7.9% = 18.5% |
| Placebo for an additional 48 weeks | 10.6% – 6.9% = 3.7% |
Over the 68-week length of the trial, patients taking semaglutide lost approximately 17.5% of their body weight, which translates into a 41-pound weight loss. The trial results demonstrate that obesity is a chronic medical condition that requires continued treatment.
STEP 5 Wegovy Research Clinical Trial
STEP 5 Wegovy clinical trial results data have been collected. The trial enrolled 304 participants with overweight or obesity and related comorbidities, but not diabetes, and extended for two years of treatment.
Along with a reduced-calorie meal plan and increased physical activity, 144 participants received 2.4 mg semaglutide after a dose-escalation period for a total of 104 weeks, and 128 participants received placebo.
| Dosage | Percent body weight reductions | Percent achieving at least 5% reduction in body weight | Percent achieving at least 10% reduction in body weight | Percent achieving at least 15% reduction in body weight |
|---|---|---|---|---|
| 2.4 mg semaglutide | 15.2% | 77.1% | 61.8% | 52.1% |
| placebo | 2.6% | 34.4% | 13.3% | 7.0% |
In addition to weight loss, participants who took semaglutide had:
- 14.4 cm reduction in waist circumference
- 5.7 mm Hg reduction in systolic blood pressure
- 4.5 mm Hg reduction in diastolic blood pressure
- .42 % reduction in Hb A1c
- 7.6 mg/dL reduction in fasting blood glucose
- 19 mg/dL reduction in triglycerides
STEP 6 Wegovy Research Clinical Trial
STEP 6 Wegovy clinical trial investigates the safety and effectiveness of Wegovy for East Asia adults with overweight or obesity. 401 people from Japan and South Korea were enrolled in this clinical trial. 199 participants received 2.4 mg/week over 68 weeks of treatment.
| Dosage | Percent body weight reductions | Percent achieving at least 5% reduction in body weight | Percent achieving at least 10% reduction in body weight | Percent achieving at least 15% reduction in body weight |
|---|---|---|---|---|
| 2.4 mg semaglutide | 13.2% | 83% | 61% | 41% |
| placebo | 2.1% | 21% | 5% | 3% |
In addition to weight loss, after semaglutide treatment, participants had improvements in blood pressure, lipid profiles, inflammatory markers, and approximately a 2% reduction in HgA1C.
Participants receiving 2.4 mg semaglutide also had an average 11.1 cm reduction in waist circumference, which corresponded to a 40% reduction in visceral fat.
STEP 7 Wegovy Research Clinical Trial
STEP 7 Wegovy clinical trial investigates the safety and effectiveness of Chinese adults with overweight or obesity. The study has enrolled 375 participants to randomly receive semaglutide 2.4 mg or placebo. The trial has an estimated completion date of August 2022.
STEP 8 Wegovy Research Clinical Trial
STEP 8 Wegovy clinical trial enrolled 338 randomized participants and assessed the safety and effectiveness of once-weekly 2.4 mg semaglutide versus 3.0 g once-daily liraglutide in people with overweight or obesity. Participants were randomized to receive semaglutide, liraglutide, or placebo.
| Dosage | Percent body weight reductions | Percent achieving at least 10% reduction in body weight | Percent achieving at least 15% reduction in body weight | Percent achieving at least 20% reduction in body weight |
|---|---|---|---|---|
| 2.4 mg semaglutide weekly | 15.8% | 70.9% | 55.6% | 38.5% |
| 3.0 mg liraglutide daily | 6.4% | 25.6% | 12% | 6% |
Approximately 13.5% of participants discontinued semaglutide and 27.6% discontinued liraglutide. Glucagon-like peptide-1 (GLP-1) analogues are known for causing gastrointestinal side effects, which may decrease with a dosage change.
STEP TEENS
The STEP TEENS clinical trial tests Wegovy’s effectiveness and safety in treating adolescents with overweight or obesity.
SELECT Wegovy Research Clinical Trial
Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity (SELECT) trial focuses on exploring the effects of 2.4 mg semaglutide on reducing cardiovascular events in people with cardiovascular disease and overweight or obesity. The trial is active, no longer recruiting, and is expected to have results in September 2023.
Summary
A summary of anticipated weight loss with the following treatment options:
Intensive behavioral interventions, defined as at least 14 counseling sessions in six months, are associated with a mean weight loss of 5% to 10% of body weight.
Adding a low-calorie, 1,000 to 1,200 kcal/day, portion-controlled diet can add an additional 3% to 5% weight loss.
Adding liraglutide 3 mg, a once-daily GLP-1 medication FDA-approved for weight management can add another 3% to 5% weight loss.
Adding semaglutide, a once-weekly GLP-1 medication FDA-approved for weight management can add an additional 6% to 13% weight loss.
Semaglutide plus eating a healthy diet and exercising is likely to produce a 15% to 20% weight loss, compared to an average weight loss of 5% for other weight management medications. For the more than 70% of Americans who have obesity or are overweight with a weight-related health condition, semaglutide provides a safe and effective option for long-term weight management.
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DISCLAIMER
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
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