The same peptide name can describe three very different products. An FDA-approved drug has trial data and batch testing behind it. A compounded version is made by a pharmacy under lighter rules and is not FDA-approved. A research-use-only vial is a chemical with no required testing for sterility, endotoxin or the amount inside.
Trial data reviewed by the FDA, made under drug manufacturing rules, tested batch by batch, sold with a label and usually a prefilled pen.
Wegovy, Zepbound, EgriftaLegal when the ingredient qualifies. A 503B facility follows drug manufacturing rules; a 503A pharmacy follows state rules. Neither product is FDA-approved.
Compounded semaglutide in narrow casesNo approval, no manufacturing standard, no required sterility or endotoxin testing, and a label that says it is not for people.
BPC-157, TB-500, retatrutide powdersPick a source and tap any row. Approved drugs pass every checkpoint by law. A research-use-only vial is required to pass none of them.
Optional. A freeze-dried powder sold as a chemical has no sterility or endotoxin requirement.
Costs are described in general terms only. This site does not list prices or sellers.
| FDA-approved | Compounded (503A / 503B) | Research use only | |
|---|---|---|---|
| Who regulates it | FDA | State pharmacy boards (503A); FDA (503B) | Nobody before sale |
| Prescription | Required | Required for 503A; 503B may supply clinics | None |
| Evidence behind it | Trials for this product | Borrowed from the approved drug, if one exists | Often animal studies only |
| Manufacturing standard | Current good manufacturing practice | 503B: same. 503A: USP 797, state-enforced | None |
| Sterility testing | Every batch | 503B: before release. 503A: some preparations | Optional |
| Endotoxin testing | Every batch | 503B: before release. 503A: some preparations | Optional |
| How it arrives | Prefilled pen or labeled vial | Vial and syringes, sometimes pens | Freeze-dried powder in a vial |
| Cost, in general | Highest cash price; insurance may cover | Usually lower cash price than brand | Lowest price per milligram |
| If something goes wrong | Adverse-event reporting, recalls, label changes | State complaint; 503B reports to FDA | Little or no recourse |
reports of adverse events with compounded semaglutide received by the FDA as of May 31, 2026, and more than 730 for compounded tirzepatide
FDAmore semaglutide than the label stated, in vials bought from illegal online sellers in a 2024 test-buy study
JMIR 2024how long the FDA says a multi-dose vial should be used after first puncture, even if drug is left
FDAsalt forms, semaglutide sodium and semaglutide acetate, that the FDA says are different active ingredients with no known lawful basis for compounding
FDAResearchers at the University of Pécs and UC San Diego placed six orders for semaglutide with illegal online pharmacies that sold it without a prescription. Three vials arrived; none of the three ordered pens did. All three vials failed more than half of a visual inspection checklist, and lab testing found 28.6% to 38.7% more semaglutide than the label stated.
A larger 2026 preprint, not yet peer reviewed, pooled 6,441 test results across 14 peptides from a commercial testing database and reported that 41.6% to 71.1% of samples failed basic quality criteria, depending on the method, with measurable endotoxin in 15%. Treat those numbers as provisional until the paper is published.
Approved GLP-1 pens click to a fixed amount. Vials and insulin syringes mean converting milligrams to milliliters to units, and the FDA has received reports, some with hospital stays, of people drawing the wrong amount.
Most common with compounded and research vialsA product can hold more or less drug than labeled, a different salt form, a related peptide fragment, or no active drug at all. Counterfeit Ozempic pens have also reached the US supply chain.
Research products, counterfeit pens, unlicensed online sellersAn injected product that is not sterile can cause abscesses or bloodstream infections. Endotoxin, a fragment of bacterial cell walls, can cause fever and chills even when the bacteria are dead.
Highest where no sterility or endotoxin testing is requiredWith an approved drug, side-effect reports reach the manufacturer and the FDA and can change the label. A research chemical has no reporting system, so problems stay invisible.
Research use onlyIf a clinic or pharmacy cannot answer these, that tells you something about the product.
Warning letters, recalls, compounding rules and new quality data, explained with the source linked. Daily and free. We do not sell peptides or take money from sellers.