Gray-Market Name Decoder

Why the nicknames exist

Most of the peptides sold online are sold as research chemicals, with a label saying they are not for human use. A seller who names an approved drug, or a drug still in trials, invites the attention of regulators; a nickname is softer. Some names began as shorthand on forums and stuck, some were coined by sellers, and some were picked up by the press. Whatever their origin, they now stand between a buyer and the molecule in the vial.

The FDA's position is that the label does not decide what a product is. In its statement on unapproved GLP-1 drugs, it says it has warned companies selling semaglutide, tirzepatide, retatrutide, survodutide and mazdutide labelled “for research purposes” or “not for human consumption” while selling them to consumers with dosing instructions, and that retatrutide and cagrilintide cannot be used in compounding at all (FDA). Its warning letters quote the labels sellers use, which is how one of them records a firm calling retatrutide “GLP-1-R peptide” and tirzepatide “GLP-2 peptide”.

Three ways a nickname misleads

It borrows the name of a different molecule. GLP-2 is a real hormone with a real drug based on it, teduglutide, approved for short bowel syndrome. A vial labelled GLP-2 that contains tirzepatide sends the reader to the wrong page of the textbook, and a reader looking for actual GLP-2 can end up with a weight-loss drug. GLP-1R is the standard abbreviation for the GLP-1 receptor; on a label it suggests a single GLP-1 agonist, not a triple one. GLP-3 sounds like a hormone and is not one: it counts receptors, one, two and three, a numbering with no standing in endocrinology.

It hides the amounts. A blend name says which peptides are in the vial, sometimes, but not how much of each. KLOW is usually 50 mg of GHK-Cu with 10 mg each of BPC-157, TB-500 and KPV, but at least one listing reverses the first two amounts, and in an 80 mg vial that is a fivefold difference in the dose of each. Because the ratio is fixed, a dose chosen for one component decides the dose of the others.

It means different things to different sellers. Wolverine usually means BPC-157 with TB-500, but it is also used for BPC-157 alone and for the four-peptide KLOW mix. A forum post that says “Wolverine” cannot tell you which was meant, and neither can a label that uses the name without amounts.

What a blend name does to a dose

Blend names deserve their own warning, because the arithmetic is unforgiving. In the usual KLOW vial, 50 of the 80 milligrams are GHK-Cu, so 62.5% of every dose drawn from it is GHK-Cu and 12.5% is each of the other three. Someone aiming for 250 micrograms of BPC-157 from that vial is drawing 2 milligrams of blend, and with it 1.25 milligrams of GHK-Cu. If the listing that reverses the first two amounts is the one in hand, the same draw delivers 1.25 milligrams of BPC-157 instead, five times the intended amount. The name on the vial is identical in both cases. Our blend calculator does this arithmetic for any stated composition, which is only as good as the composition the label states.

When the code name belongs to a real drug

Some names on this page are not slang at all. PT-141, SS-31 and MT-II were the laboratory code names of molecules that went on to be studied under their own names, and two of them, bremelanotide and elamipretide, are now FDA-approved drugs. That makes the research vial more confusing, not less: the approval covers a specific product, made to drug manufacturing standards, for a specific use, at a specific dose. A vial sold under the code name shares the molecule's name and nothing else, and the evidence for the approved drug says nothing about what the vial contains.

The opposite case matters too. Retatrutide has strong trial results and no approval, so a nickname that makes it sound like a newer GLP-1 drug borrows a credibility it has not yet earned. According to the FDA, it has not been found safe and effective for any condition, and it cannot be used in compounding under federal law.

What athletes should know

The anti-doping question is separate from the medical one. WADA's Prohibited List names some of these peptides outright: BPC-157 under S0, TB-500 among the thymosin beta-4 derivatives under S2.3, and CJC-1295 under S2.2.4. Peptides the List does not name are not automatically allowed: its S0 section covers substances with no current approval for human therapeutic use by any government health authority, which is where retatrutide, GHK-Cu, KPV and melanotan II sit, according to our reading of the 2026 List. A nickname is not a defence, because testing looks for the molecule, not the label.

How to decode a name

Start with the international nonproprietary name, the INN: retatrutide, tirzepatide, bremelanotide, elamipretide. Code names such as PT-141 and SS-31 were the development names of molecules that later received INNs, and in two of those cases an approved drug now exists, which makes the difference between the drug and a research vial sharper, not softer. If a seller will not name the molecule, that is the answer.

Then ask for amounts in milligrams, per molecule, and a lab report for the batch you would actually receive. A certificate of analysis that identifies the molecule by its mass, rather than by the seller's own name for it, is the only document in the chain that can settle identity; our COA decoder explains what a credible one contains. For blends, the report should quantify every component, not only the first.

Finally, look the molecule up rather than the nickname. Each card above links to the encyclopedia entry for every molecule a name points to, with its regulatory status and its standing on the World Anti-Doping Agency's 2026 Prohibited List. Athletes in tested sport should know that several of these names, among them TB-500, BPC-157 and CJC-1295, appear on that List by name, and that substances it does not name may still fall under its S0 category for unapproved substances.

How this page is sourced

Every mapping names exactly one source. Where a regulator, a journal or a news report has recorded the name, that is the source: an FDA warning letter, the WADA List, a PubMed record, or a named publication. Where only sellers use a name, the source is our own listing review, dated, and the composition is the one the listings state. We do not name or link to sellers anywhere on this site, so FDA warning letters are cited by their MARCS-CMS number and date, which is enough to find them in the FDA's own database.

A name on this page is a claim about what sellers mean, not a statement about what any particular vial contains. Research-grade products are made outside drug manufacturing standards. When vials sold online as 10 mg of melanotan II were tested, they held between 4.3 and 8.8 mg, and some carried unknown impurities (see the melanotan II entry). Even when the nickname and the molecule match, the contents still have to be shown. Our article on where gray-market peptides come from covers that side of the problem.

Names change quickly. If you meet a nickname that is not here, the same three questions apply: which molecule, how much of it, and what does the batch report show.

This page describes how products are named and sold; it is not medical advice and not a buying guide. Nothing here is a recommendation to use any of these substances.