Every other page on this site describes a substance with somewhere between zero and two controlled human trials. This page exists to make the contrast explicit. The GLP-1 receptor agonists are peptides. They have been through the process the others have not.
What they are
Glucagon-like peptide-1 is a gut hormone that increases insulin release, slows gastric emptying and reduces appetite. Liraglutide (Saxenda, Victoza), semaglutide (Ozempic, Wegovy, Rybelsus) and the dual GIP/GLP-1 agonist tirzepatide (Mounjaro, Zepbound) are engineered peptide analogues with half-lives long enough for daily or weekly injection. The science site explains the physiology with diagrams.
The evidence, in two numbers
| Trial | Design | Weight change vs placebo | PubMed |
|---|---|---|---|
| STEP 1 (semaglutide 2.4 mg) | Randomised, double-blind, placebo-controlled; 1,961 adults with obesity or overweight plus a comorbidity; 68 weeks | -14.9% vs -2.4% | 33567185 |
| SURMOUNT-1 (tirzepatide) | Randomised, double-blind, placebo-controlled; 2,539 adults; 72 weeks | -15.0%, -19.5%, -20.9% at 5, 10 and 15 mg vs -3.1% | 35658024 |
Behind these sit programmes of ten or more trials each, a cardiovascular outcomes trial for semaglutide, kidney and sleep-apnoea trials, and labels that report adverse-reaction rates from thousands of participants. The research site digests the trials one by one, and the GLP-1s Explained encyclopedia has a page per agent.
Regulatory status
Approved products, with dates from Drugs@FDA: Saxenda December 23, 2014; Ozempic December 5, 2017; Wegovy June 4, 2021; Mounjaro May 13, 2022; Zepbound November 8, 2023. All carry a boxed warning about thyroid C-cell tumours seen in rodents and a contraindication in people with a personal or family history of medullary thyroid carcinoma or MEN 2.
Compounded semaglutide and tirzepatide are a separate matter. They are not FDA approved. Whether a pharmacy may make them depends on shortage status and the conditions of section 503A and 503B, which the compounding site tracks with dates, and which FormBlends summarises on its regulatory status page.
Why this matters for the rest of the site
When a clinic offers MOTS-c or AOD-9604 "for metabolism," or tesamorelin "for belly fat," the honest comparison is with the drugs in the table above. Those have grade A evidence for weight loss. Everything else sold for the same purpose on this site has grade D. Read the methodology page for what those letters mean and do not mean.
FormBlends, which publishes this network, dispenses compounded GLP-1 medication through licensed pharmacies. That is a commercial interest and it is why this page links to an encyclopedia rather than a product page. If you want the product page, it is on formblends.com.
Questions people ask
Why are GLP-1 drugs on a research-peptide site?
Because they are peptides, and because they are the answer to the question most people asking about MOTS-c, AOD-9604 or tesamorelin for fat loss are really asking. Semaglutide and tirzepatide have approved labels, phase 3 trials in thousands of participants and, for semaglutide, a cardiovascular outcomes trial. Nothing else on this site comes close.
Where are the full pages on each GLP-1 agent?
On the GLP-1s Explained site, which has one page per agent with mechanism, approval dates, dosing per label, pivotal trial numbers and label side-effect rates, plus an agent comparison tool. This page is a pointer, not a duplicate.
Are compounded GLP-1s graded A?
No. The A grade belongs to the approved products and their labels. A compounded semaglutide or tirzepatide is not FDA approved and not interchangeable with the brand; its status depends on shortage rules and section 503A conditions that the compounding site explains. FormBlends, which runs this network, dispenses compounded GLP-1s through licensed pharmacies; that interest is disclosed on every page.
Sources
- FormBlends network: GLP-1s Explained (per-agent encyclopedia) Accessed September 4, 2026.
- Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med 2021. PubMed 33567185 Accessed September 4, 2026.
- Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med 2022. PubMed 35658024 Accessed September 4, 2026.
- Drugs@FDA: WEGOVY NDA 215256 (approved June 4, 2021); ZEPBOUND NDA 217806 (approved November 8, 2023); OZEMPIC NDA 209637 (December 5, 2017); MOUNJARO NDA 215866 (May 13, 2022); SAXENDA NDA 206321 (December 23, 2014) Accessed September 4, 2026.
- FormBlends: regulatory status of compounded GLP-1s and peptides Accessed September 4, 2026.
Canonical URL: https://formblendspeptides.com/peptides/glp-1-peptides. Written by the FormBlends editorial team. This page is educational and is not medical advice; see the medical disclaimer.