Do peptides help with obesity and chronic weight management?
6 peptides are graded for obesity and chronic weight management on this page. The strongest grade is human RCT evidence, for tirzepatide, semaglutide, liraglutide, retatrutide, and cagrilintide. Each one is weighed against the standard of care below, and the evidence table gives the grade and a note for every peptide.
What is the standard of care for obesity and chronic weight management?
Lifestyle intervention (dietary change, physical activity, behavioral support) as the base; FDA approved anti-obesity medication for BMI 30 or higher, or 27 with a comorbidity; bariatric surgery for BMI 40 or higher, or 35 with comorbidity.
Any peptide below should be judged against this baseline, not against doing nothing. Talk to a licensed provider before replacing or adding to an established treatment.
Approvals, cost, and access for the GLP-1 drugs are on the GLP-1 hub.
Which peptides have been studied for obesity and chronic weight management?
Ordered by strength of evidence for this use. Grades follow the methodology; each peptide page lists the individual studies.
| Peptide | Evidence for this use | Note |
|---|---|---|
| Tirzepatide | Evidence: Human RCT evidence | 20.9% mean weight loss at 15 mg over 72 weeks in SURMOUNT-1 (n = 2,539); FDA approved as Zepbound. [2] [3] |
| Semaglutide | Evidence: Human RCT evidence | 14.9% mean weight loss at 2.4 mg over 68 weeks in STEP 1 (n = 1,961); FDA approved as Wegovy. [1] [4] |
| Liraglutide | Evidence: Human RCT evidence | FDA approved as Saxenda; smaller effect than weekly agonists in trials. [5] |
| Retatrutide | Evidence: Human RCT evidence | Phase 2 trials published; phase 3 ongoing; not FDA approved. [6] |
| Cagrilintide | Evidence: Human RCT evidence | Amylin analog studied alone and with semaglutide; not FDA approved. [7] |
| AOD-9604 | Evidence: Animal-only evidence | Small older human trials reported no meaningful weight loss and are not indexed as controlled trials in the evidence table, so they do not raise the grade; not approved. [8] |
Head-to-head comparisons
Cost and access
Price ranges, lawful channels, and insurance notes for peptides graded here. State rules are in the legal guides by state.
Frequently asked questions
Which peptide has the strongest evidence for obesity and chronic weight management?
Tirzepatide, semaglutide, liraglutide, retatrutide, and cagrilintide have the strongest evidence among the peptides graded here, at human RCT evidence. Tirzepatide: 20.9% mean weight loss at 15 mg over 72 weeks in SURMOUNT-1 (n = 2,539); FDA approved as Zepbound. Semaglutide: 14.9% mean weight loss at 2.4 mg over 68 weeks in STEP 1 (n = 1,961); FDA approved as Wegovy. Liraglutide: FDA approved as Saxenda; smaller effect than weekly agonists in trials. Retatrutide: Phase 2 trials published; phase 3 ongoing; not FDA approved. Cagrilintide: Amylin analog studied alone and with semaglutide; not FDA approved. [1] [2] [3] [4]
Is any peptide FDA approved for obesity and chronic weight management?
Tirzepatide, semaglutide, and liraglutide are FDA approved drugs, but an approval covers only the indications on that label, so check the label before assuming it applies to obesity and chronic weight management. The other peptides graded here are not FDA approved. [1] [2] [3] [4] [9]
Has any peptide been tested in a randomized trial for obesity and chronic weight management?
Yes, for tirzepatide, semaglutide, liraglutide, retatrutide, and cagrilintide. Check each note for the population and endpoints: a randomized trial in a related group or on a surrogate marker is weaker than one on the outcome you care about. [1] [2] [3] [4]
From the blog
- Peptides for weight loss, ranked by human evidence
Tirzepatide, semaglutide, and liraglutide lead on human trials. Retatrutide is trial-only, and AOD-9604 and 5-amino-1MQ are animal-only. Ranking, legal status, and dated prices.
- Peptides for women, ranked by human evidence
GLP-1 drugs, teriparatide, abaloparatide, and Vyleesi (PT-141) have real trials in women. Kisspeptin is research-only and GHK-Cu rests on small skin studies. The ranking and legal status.
- Are peptide injections safe? What is known and unknown
FDA-approved peptide injections have documented side effects on their labels. Compounded and research-only peptides add unknowns: sterility, identity, dose accuracy, and contamination.
- 5-amino-1MQ for fat loss: mouse data, no human trials
5-amino-1MQ reduced fat mass in obese mice, but no human study of any kind has been published. What the mouse studies found, capsules vs injection, side effects, and legal status.
- Compounded tirzepatide in 2026: legality, cost, and safety
The tirzepatide shortage ended in December 2024 and routine compounded copies ended in 2025. What is still lawful, what it cost, FDA safety warnings, and how to check a pharmacy.
- Do GLP-1 patches work? What they contain and what the evidence says
No FDA-approved GLP-1 patch exists. Here is why GLP-1 drugs cannot pass through skin from a sticker, what patch ingredients have been tested by mouth, and how to read patch reviews.
More on the blog
- GLP-1 supplements vs GLP-1 drugs: what GLP-1 boosters actually do
- How to get peptides prescribed legally in 2026
- How to get retatrutide: clinical trials, expanded access, and the law
- Microdosing GLP-1s and tirzepatide: what the evidence says
- MOTS-c for weight loss: what mouse and human studies show
- Peptide before and after: trial results vs marketing photos
- Peptides for men, ranked by human evidence
- Retatrutide before and after: weight loss by dose and week in the trials
- Retatrutide benefits beyond weight loss: liver fat, blood sugar, and blood pressure
- Retatrutide side effects: what the trials reported, dose by dose
- What is peptide therapy? What clinics sell, what is legal, and what works
- GLP-1 side effects ranked by trial frequency
- How to get a compounded GLP-1 prescription in 2026
- How to read a peptide study
Sources
- [1]Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med 2021 (STEP 1)PubMed 33567185, 2021
- [2]Tirzepatide once weekly for the treatment of obesity. N Engl J Med 2022 (SURMOUNT-1)PubMed 35658024, 2022
- [3]FDA prescribing information for Zepbound (tirzepatide) injection, via DailyMedFDA, 2025
- [4]FDA prescribing information for Wegovy (semaglutide) injection, via DailyMedFDA, 2025
- [5]FDA prescribing information for Saxenda (liraglutide) injection, via DailyMedFDA, 2025
- [6]Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trialPubMed 37366315, 2023
- [7]Once-weekly cagrilintide for weight management in people with overweight and obesity: a phase 2 trialPubMed 34798060, 2021
- [8]Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormonePubMed 11146367, 2000
- [9]Drugs@FDA: FDA-approved drugs databaseFDA