Peptides for weight loss: what the human evidence supports
Where to actually get it
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Most weight loss peptides sold online have never been through a human trial. The three that have are all prescription drugs, and they are the same GLP-1 medications this site tracks every day. Semaglutide (Wegovy) cut body weight by a mean of 14.9% over 68 weeks against 2.4% on placebo in STEP 1 (n=1,961). Tirzepatide (Zepbound) cut it by 20.9% at the 15 mg dose over 72 weeks in SURMOUNT-1 (n=2,539, treatment-regimen estimand) against 3.1% on placebo. Liraglutide (Saxenda) cut it by 8.0% over 56 weeks in SCALE (n=3,731) against 2.6%.
Every other compound marketed as a weight loss peptide, AOD-9604, ipamorelin, CJC-1295, MOTS-c, tesamorelin outside its HIV indication, lacks an adequate human weight-loss trial. The table below grades each one. Those are three separate trials with different populations and durations, so the figures rank the evidence rather than the drugs against each other.
What are peptides for weight loss?
A peptide is a short chain of amino acids, a small protein. Insulin is a peptide, and so is every GLP-1 medication: semaglutide and liraglutide are engineered analogs of your own GLP-1 hormone, and tirzepatide is a synthetic peptide that activates both the GLP-1 and GIP receptors. When a telehealth ad says peptide therapy for weight loss, the compound doing the proven work is one of these three. The marketing term also gets attached to a second group, growth-hormone-axis compounds sold in vials by research-chemical sites, and that group has a fundamentally different evidence base, which is to say none in humans for weight loss.
Every peptide marketed for weight loss, graded by human evidence
| Peptide | Best human weight-loss evidence | Status |
|---|---|---|
| Semaglutide (Wegovy) | STEP 1, n=1,961: mean 14.9% loss at 68 weeks vs 2.4% placebo | FDA approved for weight management |
| Tirzepatide (Zepbound) | SURMOUNT-1, n=2,539: 15.0% to 20.9% loss by dose at 72 weeks vs 3.1%, treatment-regimen estimand | FDA approved for weight management |
| Liraglutide (Saxenda) | SCALE, n=3,731: mean 8.0% loss at 56 weeks vs 2.6% placebo | FDA approved for weight management |
| Tesamorelin (Egrifta) | Reduces excess abdominal fat in HIV-associated lipodystrophy; its label states it is not indicated for weight loss management | Approved for a different condition |
| AOD-9604 | No adequate human weight-loss RCT; its commercial obesity program ended without a positive pivotal trial | Unapproved; gray market only |
| CJC-1295 | No human weight-loss RCT | Unapproved; gray market only |
| Ipamorelin | No human weight-loss trial; it stimulates the ghrelin receptor, the pathway that drives hunger | Unapproved; gray market only |
| MOTS-c | Animal and cell data only | Unapproved; gray market only |
Trial figures are taken from each publication's own primary endpoint reporting. For peptides beyond the weight-loss question, BPC-157 through GHK-Cu, see bestpeptideforthat.com, an independent directory that grades every peptide A to F by strength of human evidence.
Where to buy peptides for weight loss legally
The legal line is plain: research-use-only peptides are not legal for human consumption. The vials sold by research-chemical sites are unapproved drugs when sold for people to inject, with no verification of identity, purity, dose or sterility behind the label. A licensed clinician cannot prescribe them for weight loss, and a state-licensed pharmacy cannot dispense them for it. Any site willing to sell you AOD-9604 or CJC-1295 for weight loss is operating outside the drug supply chain, and this page will not point you to one.
The legal route is a prescription GLP-1 through a licensed program. The highest-scoring program on our index that offers one is Fridays (8.7/10), and for daily liraglutide specifically the top-scoring option is Henry Meds (8.4/10). The full price-sorted field is on the cheapest programs page, and the match quiz narrows it to your situation in seven questions.
What the proven peptides cost
Manufacturer list prices are the ceiling, and both manufacturers now sell direct for far less. Wegovy lists at $1,349/mo, with NovoCare self-pay at $199/mo (pen $199/mo for the first two 0.25 mg or 0.5 mg fills through December 31, 2026, then $349/mo at standard strengths or $399/mo for Wegovy HD; oral pill from $149/mo, dose-dependent). Zepbound lists at $1,086/mo, with LillyDirect self-pay vials from $299/mo at the 2.5 mg starter dose, $399 at 5 mg, and $449 at 7.5 mg and above when refilled within 45 days. Saxenda lists at $1,349.02 with no manufacturer self-pay program. Figures verified 2026-08-14 and 2026-08-07 on Novo's and Lilly's own pages.
The cheapest route to the proven molecules is compounded semaglutide or tirzepatide through a telehealth program. The trade-off is regulatory rather than chemical: a compounded product is not an FDA-approved finished product, so the agency does not review it for safety, effectiveness or quality before sale. Unlike a research-chemical vial, it is prepared for a named patient by a state-licensed pharmacy under a prescription. Every price below is one we re-checked ourselves.
- 1Embody7.3/10 · from · price checked 2026-08-15from $69/moVisit
- 2Strut Health6.2/10 · from · price checked 2026-07-31from $99/moVisit
- 3GobyMeds8.4/10 · from · price checked 2026-07-31from $99/mo
- 4HealthRX5.2/10 · from · price checked 2026-07-31from $99/moVisit
- 5Sprout Health5.8/10 · flat rate · price checked 2026-08-26$110/moVisit
Sorted by verified price, not by who pays us. How we rank. Full molecule guides: semaglutide and tirzepatide.
Frequently Asked Questions
What are peptides for weight loss?
Peptides are short chains of amino acids, and several prescription drugs are peptides. The ones with proven weight-loss efficacy in humans are the GLP-1 class: semaglutide lost 14.9% of body weight over 68 weeks in the STEP 1 trial against 2.4% on placebo, tirzepatide lost 20.9% at the 15 mg dose over 72 weeks in SURMOUNT-1 under the trial's treatment-regimen estimand, and liraglutide lost 8.0% over 56 weeks in SCALE. Compounds sold online as weight loss peptides outside that class, such as AOD-9604, ipamorelin, CJC-1295 and MOTS-c, have no adequate human weight-loss trial behind them.
Which peptides are FDA approved for weight loss?
Three: semaglutide 2.4 mg (Wegovy), tirzepatide (Zepbound) and liraglutide 3.0 mg (Saxenda), each approved for chronic weight management alongside diet and exercise. Tesamorelin (Egrifta) is a peptide approved only to reduce excess abdominal fat in HIV-associated lipodystrophy, and its label states it is not indicated for weight loss management. AOD-9604, ipamorelin, CJC-1295 and MOTS-c are not FDA-approved drugs for any indication.
Where can I buy peptides for weight loss?
Legally, through a prescription. Licensed telehealth programs prescribe the FDA-approved GLP-1 peptides, and some offer compounded semaglutide or tirzepatide prepared by state-licensed pharmacies; compounded products are not FDA-approved, and verified program prices on our index start at $69/mo. Peptide vials sold online as research chemicals are unapproved drugs that are not legal to buy for human use, no clinician can prescribe them for weight loss, and nothing verifies what is actually in the vial.
Do AOD-9604, ipamorelin, or CJC-1295 work for weight loss?
No adequate human randomized trial shows weight loss for any of the three. AOD-9604 is a growth hormone fragment whose commercial obesity development ended without a positive pivotal trial. CJC-1295 raises growth hormone levels and has never been tested for weight loss in a human RCT. Ipamorelin stimulates the ghrelin receptor, and ghrelin is the hormone that drives hunger, which points in the wrong direction for weight loss. All three are sold outside the regulated drug supply.
Medical disclaimer: This page summarizes published trial evidence and pricing for informational purposes only and does not constitute medical advice. GLP-1 medications are prescription drugs; consult a licensed healthcare provider.