Evidence digest
Semaglutide has one of the strongest human evidence bases of any compound in this index — and none of it attaches to research-grade powder. The randomised controlled trials were run on an approved pharmaceutical product of verified identity and purity, administered under medical supervision. Material sold for research use is not that product, and the trial evidence does not transfer to it. What a research-grade vial contains is established only by its certificate of analysis, if one exists.
Updated 22 Jul 2026 · 6 studies indexed · 6 human · compound record
| Study | Evidence type | Model | n | What it reported | Source |
|---|---|---|---|---|---|
| Randomised controlled trials of semaglutide, the approved medicinePubMed listing | Human — controlled trial | Not recorded | — | Placeholder seed record. An extensive randomised controlled trial literature exists for the approved pharmaceutical product, conducted under medical supervision with a product of verified identity and purity. It is evidence about that product, not about research-grade material of unverified content. | Listing |
| Meta-analyses of GLP-1 receptor agonist trialsPubMed listing | Meta-analysis | Not recorded | — | Placeholder seed record. Pooled analyses of trials of approved GLP-1 receptor agonist products. Meta-analytic findings inherit the population and product of the trials they pool, and do not transfer to material obtained outside that supply chain. | Listing |
| Once-Weekly Semaglutide in Adults with Overweight or ObesityThe New England journal of medicine · 2021 | Human — controlled trial | Not recorded | — | Obesity is a global health challenge with few pharmacologic options. Whether adults with obesity can achieve weight loss with once-weekly semaglutide at a dose of 2.4 mg as an adjunct to lifestyle intervention has not been confirmed. In this double-blind trial, we enrolled 1961 adults with a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or greater (≥27 in persons with ≥1 weight-related coexisting condition), who di… | PMID 33567185 |
| Tirzepatide as Compared with Semaglutide for the Treatment of ObesityThe New England journal of medicine · 2025 | Human — controlled trial | Not recorded | — | Tirzepatide and semaglutide are highly effective medications for obesity management. The efficacy and safety of tirzepatide as compared with semaglutide in adults with obesity but without type 2 diabetes is unknown. In this phase 3b, open-label, controlled trial, adult participants with obesity but without type 2 diabetes were randomly assigned in a 1:1 ratio to receive the maximum tolerated dose of tirzepatide (10 mg or 15 mg) or the maximum tolerated dose of semaglutide (1.… | PMID 40353578 |
| Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extensionDiabetes, obesity & metabolism · 2022 | Human — controlled trial | Not recorded | — | To explore changes in body weight and cardiometabolic risk factors after treatment withdrawal in the STEP 1 trial extension. STEP 1 (NCT03548935) randomized 1961 adults with a body mass index ≥ 30 kg/m2 (or ≥ 27 kg/m2 with ≥ 1 weight-related co-morbidity) without diabetes to 68 weeks of once-weekly subcutaneous semaglutide 2.4 mg (including 16 weeks of dose escalation) or placebo, as an adjunct to life… | PMID 35441470 |
| Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical TrialJAMA · 2021 | Human — controlled trial | Not recorded | — | The effect of continuing vs withdrawing treatment with semaglutide, a glucagon-like peptide 1 receptor agonist, on weight loss maintenance in people with overweight or obesity is unknown. To compare continued once-weekly treatment with subcutaneous semaglutide, 2.4 mg, with switch to placebo for weight maintenance (both with lifestyle intervention) in adults with overweight or obesity after a 20-week run-in with subcutaneous semaglutide titrated to 2.4 mg weekly. Randomized, … | PMID 33755728 |
Placeholder seed entry recording the source, not an event. The European Medicines Agency publishes decisions on marketing authorisation. Approval status matters to this index because it determines whether the substance in a research-grade vial has an approved counterpart at all — and therefore whether a published trial literature exists for a product that is not the one being sold.
Placeholder seed entry recording the source, not an event. The FDA maintains categorised lists of bulk drug substances nominated for use in compounding, including substances it has evaluated and placed in the category that may not be compounded. Several peptides tracked in this index have appeared in these evaluations. PepIndex records movements between categories here as they are observed; the linked page is the authoritative listing.
Placeholder seed entry recording the source, not an event. Shortage status for approved GLP-1 products materially affects this market: when an approved product is listed as in shortage, compounding of that substance becomes permissible under conditions, and demand shifts toward alternative supply. Resolution of a shortage reverses that. PepIndex records status changes here because they move the whole category.
The FDA proposed leaving semaglutide, tirzepatide and liraglutide off the 503B bulk drug substances list, finding no clinical need for outsourcing facilities to compound them from bulk now that the GLP-1 shortages are resolved. If finalized, the exclusion would close the last routine legal pathway for large-scale compounded GLP-1s and further narrow the supply of non-branded semaglutide and tirzepatide. The FDA took comments on the proposal through mid-2026 and is reviewing them; a final determination had not been published as of this writing.
The FDA confirmed the semaglutide shortage was resolved and set deadlines for compounders to stop making copies of the branded GLP-1 drug. Because the exemption allowing 503A and 503B facilities to compound semaglutide depended on its shortage status, removal from the list narrows the legal space in which compounded and “research” semaglutide is supplied.
The FDA warned SwissChems that its semaglutide and retatrutide products — sold as research chemicals but promoted for human weight and metabolic use — are unapproved new drugs and misbranded under the FD&C Act. It is one of a series of letters the agency has issued to vendors offering GLP-1 and research peptides directly to the public.
The evidence above describes the published literature. What any individual vial contains is a separate question, answered by that vendor’s certificate records rather than by any study on this page.
| Vendor | Score · Coverage | Certificates | |
|---|---|---|---|
| Polaris Peptides | 93.877% | 8 | profile → |
| PeptidePlugs | 89.790% | 2 | profile → |
| Hydro Research Peptides | 88.289% | 2 | profile → |
| Prime Peptides | 87.180% | 1 | profile → |
| American Peptides | 83.6100% | 1 | profile → |
| Northline Labs | 79.493% | 1 | profile → |
| Ascension Peptides | 78.186% | 1 | profile → |
| Simple Peptide | 7489% | 1 | profile → |
How to read this page
This digest describes what published research exists and what it does not establish. It is not a recommendation, contains no dosing information or protocols, and makes no claim that any compound is safe or effective for any purpose. Material listed by indexed vendors is labeled for laboratory research use only.