How much weight can you lose on semaglutide? In the STEP 1 trial, adults without diabetes lost an average of 14.9% of their body weight over 68 weeks on weekly semaglutide plus lifestyle support, compared with 2.4% on placebo. Your own result may land above or below that average.
Written by Kiara DeWitt, BSN, RN, CPN
Medically reviewed by Dr. Josh Allen, D.O., Medical Director, October 23, 2026
Disclaimer: This guide is for general education and does not replace advice from your own clinician. Semaglutide needs a prescription and a medical evaluation, and results differ between people.
This guide covers what the clinical data shows, how quickly weight tends to come off and what affects your results. One thing to keep in mind throughout: every number here comes from the FDA-approved weekly injection used in the trial. Compounded semaglutide is not FDA-approved and has no trial data of its own.
STEP 1 followed 1,961 adults with a BMI of 30 or more, or 27 or more with at least one weight-related condition. None had diabetes. Two out of three were assigned to weekly semaglutide and one out of three to placebo, and both groups got the same lifestyle program for 68 weeks.
| Result at week 68 | Semaglutide | Placebo |
|---|---|---|
| Average weight lost | 14.9% of body weight | 2.4% of body weight |
| Lost 5% or more | 86.4% of participants | 31.5% of participants |
| Lost 10% or more | 69.1% | 12.0% |
| Lost 15% or more | 50.5% | 4.9% |
| Lost 20% or more | 32.0% | 1.7% |
| Average change in waist size | About 13.5 cm smaller (5.3 in) | About 4.1 cm smaller (1.6 in) |
The threshold shares are among participants who had a weight recorded at week 68, and the 20% threshold was reported outside the trial’s formal statistical testing. Read the table as trial averages, not a prediction for any one person.
STEP 1 was designed to answer one question at one point in time: how much weight people had lost by week 68. It doesn’t give a month-by-month forecast, and the monthly percentages you see quoted online are not results the trial published.
What the trial does tell you is that weight loss built gradually over many months while the dose was raised step by step at the start. Nausea and diarrhea were the most common side effects, usually mild to moderate, and they tended to settle with time.
The practical takeaway: judge your progress in months, not weeks. A slow first month is not a sign that semaglutide has failed.
| Factor | Why it matters | What helps |
|---|---|---|
| Starting weight and BMI | A higher starting weight usually means more pounds lost, but trials compare results as a percentage | Track your percent change, not just pounds |
| Your treatment plan | Your prescriber adjusts the plan to how you respond and what you tolerate | Ask before changing anything on your own |
| Protein and strength training | A smaller appetite can quietly cut your protein and speed up muscle loss | A protein target set by your provider, plus regular resistance training |
| Metabolic conditions | Insulin resistance, hypothyroidism or PCOS may slow early progress | Managing the condition alongside treatment |
| Sleep and stress | Both shape appetite, cravings and food choices | Raise them at your check-ins |
| Taking it as prescribed | Missed doses interrupt treatment | Ask your provider how to restart instead of guessing |
A note on metabolic conditions: slower early results don’t mean semaglutide isn’t working. They usually mean the underlying condition needs attention at the same time.
SURMOUNT-5 put the two medications side by side in 751 adults with obesity but without type 2 diabetes. After 72 weeks, average weight loss was 13.7% with semaglutide and 20.2% with tirzepatide, and waist size dropped by about 13.0 cm and 18.4 cm.
Both are prescription medications, and a bigger trial average doesn’t make one the right choice for everyone. Your health history, side effects and how you respond all matter. For the tirzepatide trial data, see how much weight you can lose on tirzepatide.
Find out whether a medically supervised semaglutide plan makes sense for you.
$425 a month or $1,800 for a 6 to 8 month program
The FDA label for semaglutide for weight management lists nausea, diarrhea, vomiting, constipation, abdominal pain, headache and fatigue among the most common side effects. Here is how the common ones are usually handled.
Nausea is most common early on and while the dose is being increased. Eating smaller, more frequent meals, going easy on high-fat foods and not lying down right after eating can help. It usually eases as your body adjusts.
Semaglutide slows how fast your stomach empties, so bowel movements can slow down too. Increase fiber gradually, drink plenty of water and stay active. A fiber supplement may help if food changes aren’t enough.
Some people feel low on energy in the first weeks, especially around dose increases. It often settles on its own. Enough protein, fluids and a steady sleep schedule make this stretch easier.
The current FDA label for semaglutide for weight management carries a boxed warning about thyroid C-cell tumors seen in rodents (it is not known whether this happens in people), and it is not used by anyone with a personal or family history of medullary thyroid cancer or MEN 2. It also warns about less common but serious problems, including acute pancreatitis, gallbladder problems such as gallstones, low blood sugar (mainly in people with diabetes who also take insulin or a sulfonylurea), kidney injury and serious allergic reactions. Tell your provider promptly about any symptom that is severe, keeps getting worse or doesn’t go away.
In the STEP 1 extension study, researchers followed a group of participants for a year after treatment and the trial’s lifestyle program ended. Much of the weight they had lost came back, and most of the gains in heart and metabolic health markers drifted back toward where they started. The authors saw this as a sign that obesity is a chronic condition, not a failure of the medication.
When semaglutide stops, appetite and cravings tend to return to your old baseline, and old eating habits can come back with them. Steady eating patterns, regular exercise, enough sleep and stress management all help you hold on to your progress. Talk to your provider before stopping, and for practical steps, read how to avoid weight gain after stopping semaglutide.
STEP 1 reported its main results at 68 weeks, not 3 months, so there’s no published 3-month average to quote. By week 68, 86.4% of participants had lost at least 5% of their body weight and 69.1% at least 10%. Weight comes off gradually across the first months, so treat three months as an early progress check, not a final verdict.
There’s no honest answer in weeks for a set number of pounds. Twenty pounds is a much bigger share of body weight for a 170-pound person than for a 280-pound person, which is why trials report percentages. Set a percent goal with your provider, then watch the trend at each check-in rather than the scale on any single day. Individual results vary.
Semaglutide lowers overall body weight. It can’t target belly fat on its own. In STEP 1, waist size shrank by about 13.5 cm on average with semaglutide, compared with about 4.1 cm on placebo, as overall weight came down. Pairing treatment with regular activity, including strength training, helps you keep muscle while the fat comes off.
Focus on the habits that make the medication work harder for you: enough protein at each meal, resistance training a few times a week, consistent sleep and taking your medication as prescribed. Don’t change your treatment on your own to go faster. If progress stalls for several weeks, ask your provider to review your plan with you.
It can’t be assumed to. Compounded drugs are not FDA-approved, and the FDA does not verify their safety, effectiveness or quality before they’re marketed. The STEP 1 results come from the FDA-approved product, so they don’t transfer automatically to compounded versions. At InjectCo, compounded semaglutide is prescribed only after a medical evaluation, with check-ins throughout your program.
Weight can come back after you stop. In the STEP 1 extension, much of the lost weight returned within a year once treatment ended. That’s why your plan should include maintenance: steady eating habits, regular activity and follow-up visits. Talk with your provider before you stop, so you can plan the next step together rather than stopping abruptly.
Semaglutide for weight management is for adults with a BMI of 30 or higher, or 27 or higher with at least one weight-related condition such as high blood pressure, type 2 diabetes or high cholesterol. It needs a medical evaluation and a prescription.
The label carries a boxed warning about thyroid C-cell tumors, which were seen in rodents. Semaglutide is not used if you or a family member has had medullary thyroid carcinoma, if you have multiple endocrine neoplasia syndrome type 2 (MEN 2), or if you’ve had a serious allergic reaction to semaglutide or its ingredients. The label also says to stop it once a pregnancy is recognized. For the full list, see who should not take semaglutide.
At InjectCo, a licensed prescriber working under Dr. Josh Allen, D.O., Medical Director, decides whether semaglutide is right for you. Our compounded semaglutide program is $425 a month or $1,800 for a 6 to 8 month program and includes your consult, labs, medication when prescribed, check-ins every 2 weeks and a monthly dose review. Visits happen in person or by telehealth, and you can pay self-pay or with an HSA/FSA card.
Speak with an InjectCo nurse about whether semaglutide fits your plan.
$425 a month or $1,800 for a 6 to 8 month program
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