Peptide Vendor Code Names Decoded: GLP-3, MHC-3 RT & More

If you have shopped for GLP-1 research compounds, you have run into product names that explain nothing: GLP-3 RT, ION-3R, EZP-3P, R-30, T-10, MHC-2 TRZ, GLP-1SG. They look like different products from different chemical families. They are not. Most of them are three compounds wearing eleven different names.

This page is the decoder. Every code below was confirmed against the vendor's own live catalogue rather than inferred from the pattern, because inference gets it wrong. Ion's "P-14", for example, looks like a peptide fragment and resolves to PT-141.

Research-context information only. Compounds discussed below are research peptides and supplements; some are investigational drugs not approved by the FDA. Protocols, doses, and reactions reported come from published research and self-reported community sources. Possession or use of investigational drugs outside an authorized clinical trial may be illegal in your jurisdiction. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.

Why the codes exist

Two reasons, and they pull in the same direction.

The first is regulatory. GLP-1 receptor agonists are the most heavily scrutinised category in the research-compound market. In March 2026 the FDA issued a warning letter to one vendor citing four products by name — "GLP-1 SM", "GLP-2 TRZ", "GLP-3 RT" and "BAC Water" — as unapproved new drugs. A coded SKU is harder for an automated sweep to flag than a listing that says "retatrutide". That does not change the compound's status — retatrutide and cagrilintide remain investigational drugs with no FDA approval regardless of which SKU a vendor sells them under.

The second is commercial, and it is the one that costs you money. When the same compound is listed as GLP-3 RT at one vendor, EZP-3P at another, and R-30 at a third, you cannot compare prices without translating first. The spread between the cheapest and most expensive source of the identical compound is routinely 2-3x.

The decoder

Retatrutide

A triple agonist targeting GLP-1, GIP and glucagon receptors. The most heavily coded compound in the market.

Also written as: glp3 reta, glp-3 retatrutide, cagri/glp-3rt, glp3-rt (25mg) / cagrilintide (5mg).

Dosing note: searches for "GLP-3 dosing" or "GLP-3 dosage chart" are asking about retatrutide. The code has no bearing on protocol — see the retatrutide dosing guide for what the published research actually documents.

Tirzepatide

A dual GIP/GLP-1 receptor agonist.

Semaglutide

A GLP-1 receptor agonist.

Cagrilintide

An amylin analogue, usually sold blended with retatrutide.

Non-GLP-1 codes worth knowing

How to read the number

In almost every system, the number is milligrams per vial, not a potency grade or a generation number.

• R-30 = retatrutide, 30mg
• ION-2T 60mg = tirzepatide, 60mg
• T-10 = tirzepatide, 10mg

The exception is the family digit in codes like GLP-1SG, GLP-2T and GLP-3R, where the digit indexes the compound — 1 for semaglutide, 2 for tirzepatide, 3 for retatrutide — and the milligrams appear separately.

What the code does not tell you

A code name is a naming convention. It carries no information about:

• Purity or identity. Only a Certificate of Analysis does that, and only if the batch number on the COA corresponds to the batch number on the vial received. Whether those two numbers match is the most basic traceability check available, and reviewers of at least one vendor have reported that they did not.
• Price per milligram. This is where the codes cost real money. The same compound at the same vial size can differ by more than 2x between vendors.
• Whether the vendor is worth buying from. In 2026 a federal court sentenced the founder of one peptide vendor to 70 months in prison after he admitted forging laboratory certificates, and government testing found six compounds sold as testosterone-mimics all contained actual testosterone. Certificates are only as good as the lab that issued them and the traceability behind them.

Translate, then compare

Once you know the codes map to the same compound, the comparison is straightforward — and usually surprising.

For live price-per-milligram on every vendor we track, use the full price comparison, or go straight to the buying guide for the compound you are actually after:

• Retatrutide buying guide — GLP-3, MHC-3 RT, ION-3R, EZP-3P, R-30
• Tirzepatide buying guide — GLP-2, MHC-2 TRZ, ION-2T, EZP-2P, T-30
• Semaglutide buying guide — GLP-1SG, MHC-1 SM, ION-1S, EZP-1P, S-5