Semaglutide for Weight Loss: What the Evidence Shows
What human and animal studies show about Semaglutide for weight loss, how strong that evidence is, and what is still unproven.
- Strongest evidence
- Human RCT
- Human studies
- 1,978
- PubMed records, our ledger
- Animal studies
- 160
- PubMed records, our ledger
- Studies we summarised
- 14
- with an outcome for weight loss
Evidence for weight loss
Each row is an outcome related to weight loss from a published study, strongest design first. Animal and cell results are labelled and are not human results. User reports are not counted as evidence here.
| Outcome | Result | Study type | Source |
|---|---|---|---|
| Body weight change (oral) | Oral semaglutide changed body weight by -13.6% vs -2.2% with placebo at week 64. | Human RCTn = 307 | The New England journal of medicine 2025, PMID 40934115 |
| Body weight change at 7·2 mg | Bodyweight changed by -18·7% with 7·2 mg vs -15·6% with 2·4 mg and -3·9% with placebo. | Human RCTn = 1407 | The lancet. Diabetes & endocrinology 2025, PMID 40961952 |
| Knee osteoarthritis pain (WOMAC) | Pain score changed by -41.7 points with semaglutide vs -27.5 with placebo at week 68. | Human RCTn = 407 | The New England journal of medicine 2024, PMID 39476339 |
| Body weight | Body weight changed by -13.7% with semaglutide vs -3.2% with placebo. | Human RCTn = 407 | The New England journal of medicine 2024, PMID 39476339 |
| Symptoms and body weight | The symptom score improved by 16.6 points with semaglutide vs 8.7 with placebo, and body weight changed by -13.3% vs -2.6%. | Human RCTn = 529 | The New England journal of medicine 2023, PMID 37622681 |
| Weight change vs liraglutide | Weight changed by -15.8% with semaglutide vs -6.4% with liraglutide and -1.9% with placebo. | Human controlled trialn = 338 | JAMA 2022, PMID 35015037 |
| Body weight change | Mean body weight changed by -14.9% with semaglutide vs -2.4% with placebo at week 68 (difference -12.4 percentage points). | Human RCTn = 1961 | The New England journal of medicine 2021, PMID 33567185 |
| Weight reduction thresholds | At week 68, 86.4%, 69.1% and 50.5% on semaglutide lost at least 5%, 10% and 15% of body weight, vs 31.5%, 12.0% and 4.9% on placebo. | Human RCTn = 1961 | The New England journal of medicine 2021, PMID 33567185 |
| Weight maintenance | From week 20 to week 68, body weight changed by -7.9% with continued semaglutide vs +6.9% after switching to placebo. | Human RCTn = 803 | JAMA 2021, PMID 33755728 |
| Waist circumference and systolic blood pressure | Continued semaglutide improved waist circumference (-9.7 cm) and systolic blood pressure (-3.9 mm Hg) versus placebo. | Human RCTn = 803 | JAMA 2021, PMID 33755728 |
| Body weight change | Mean bodyweight changed by -9·6% with semaglutide 2·4 mg vs -3·4% with placebo at week 68 in people with diabetes. | Human RCTn = 1210 | Lancet 2021, PMID 33667417 |
| Body weight change with behavioral therapy | With intensive behavioral therapy, body weight changed by -16.0% with semaglutide vs -5.7% with placebo at week 68. | Human RCTn = 611 | JAMA 2021, PMID 33625476 |
| Body weight vs dulaglutide | Bodyweight fell by 4·6 kg with semaglutide 0·5 mg vs 2·3 kg with dulaglutide 0·75 mg. | Human controlled trialn = 1201 | The lancet. Diabetes & endocrinology 2018, PMID 29397376 |
| Weight loss, tirzepatide vs semaglutide | Tirzepatide users lost more weight than semaglutide users: differences of -2.4% at 3 months, -4.3% at 6 months and -6.9% at 12 months. | Human observationaln = 18386 | JAMA internal medicine 2024, PMID 38976257 |
| Lean mass | Lean mass losses ranged from almost 0% to 40% of total weight reduction in some studies. | Systematic reviewn = 1541 | Expert opinion on pharmacotherapy 2024, PMID 38629387 |
| Semaglutide vs other drugs | In a post-hoc analysis, semaglutide gave an odds ratio of 9·82 for 5% or more weight loss and a mean bodyweight change of -11·40% versus lifestyle alone. | Meta-analysisn = 48209 | Lancet 2024, PMID 38582569 |
| Weight loss | Versus controls, the drug class reduced body weight by 5.319 kg and waist circumference by 4.302 cm. | Meta-analysisn = 15135 | The American journal of clinical nutrition 2023, PMID 37661106 |
| Semaglutide ranking | Semaglutide was suggested as the most effective agent in the class, with high to moderate certainty evidence. | Meta-analysisn = 15135 | The American journal of clinical nutrition 2023, PMID 37661106 |
PubMed records for Semaglutide and weight loss: 1,978 human, 160 animal (search counts, not studies we reviewed). Grades follow our evidence scale.
How strong is it?
Strongest evidence:Human RCT evidence, 4 of 4The New England journal of medicine 2025, PMID 40934115
A human randomized trial outweighs any number of animal studies. Animal and cell results show a mechanism worth testing, not that it works in people.
Other peptides people research for weight loss
All peptides for weight loss, comparedCommon questions
Does Semaglutide help with weight loss?
The strongest study we summarise for weight loss is human rct evidence, across 14 studies with an outcome for weight loss. A trial result is not an approval; see the legal status.
Is Semaglutide approved for weight loss?
Semaglutide is FDA approved (Ozempic, Wegovy, Rybelsus). Which conditions that approval covers is set by the label; use for anything else is off-label.
What is the best peptide for weight loss?
There is no single answer. Our weight loss overview compares each candidate by evidence grade and legal status rather than by popularity.
More on Semaglutide
DosageDoses used in published studies, with the source for each.CalculatorVial, water and dose to syringe units.Side effectsWhat labels and studies report, and what is unknown.ResultsStudy outcomes and when they were measured.PricePrice per mg and per week from dated listings. No vendor links.Legal statusFDA, compounding and WADA status with dates.
Sources
- 1Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity.The New England journal of medicine · 2025PMID 40934115Accessed 2 Oct 2026
- 2Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial.The lancet. Diabetes & endocrinology · 2025PMID 40961952Accessed 2 Oct 2026
- 3Once-Weekly Semaglutide in Persons with Obesity and Knee Osteoarthritis.The New England journal of medicine · 2024PMID 39476339Accessed 2 Oct 2026
- 4Semaglutide in Patients with Heart Failure with Preserved Ejection Fraction and Obesity.The New England journal of medicine · 2023PMID 37622681Accessed 2 Oct 2026
- 5Effect 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 · 2022PMID 35015037Accessed 2 Oct 2026
- 6Once-Weekly Semaglutide in Adults with Overweight or Obesity.The New England journal of medicine · 2021PMID 33567185Accessed 2 Oct 2026
- 7Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial.JAMA · 2021PMID 33755728Accessed 2 Oct 2026
- 8Semaglutide 2·4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial.Lancet (London, England) · 2021PMID 33667417Accessed 2 Oct 2026
- 9Effect of Subcutaneous Semaglutide vs Placebo as an Adjunct to Intensive Behavioral Therapy on Body Weight in Adults With Overweight or Obesity: The STEP 3 Randomized Clinical Trial.JAMA · 2021PMID 33625476Accessed 2 Oct 2026
- 10Semaglutide versus dulaglutide once weekly in patients with type 2 diabetes (SUSTAIN 7): a randomised, open-label, phase 3b trial.The lancet. Diabetes & endocrinology · 2018PMID 29397376Accessed 2 Oct 2026
- 11Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity.JAMA internal medicine · 2024PMID 38976257Accessed 2 Oct 2026
- 12A systematic review of the effect of semaglutide on lean mass: insights from clinical trials.Expert opinion on pharmacotherapy · 2024PMID 38629387Accessed 2 Oct 2026
- 13Pharmacotherapy for adults with overweight and obesity: a systematic review and network meta-analysis of randomised controlled trials.Lancet (London, England) · 2024PMID 38582569Accessed 2 Oct 2026
- 14The Weight-loss Effect of GLP-1RAs Glucagon-Like Peptide-1 Receptor Agonists in Non-diabetic Individuals with Overweight or Obesity: A Systematic Review with Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials.The American journal of clinical nutrition · 2023PMID 37661106Accessed 2 Oct 2026
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