Melanotan Peptides in Canada

One receptor family, three distinct molecules

The compounds in this group are structural analogues of alpha-melanocyte-stimulating hormone, a 13-residue endogenous peptide, and they are classed together because they bind the melanocortin receptor family. Naming the receptor family is a statement about what these molecules are; it is not a statement about what happens when one is used, and this site makes no such statement anywhere.

Three separate substances sit in this group and they are routinely treated as interchangeable in casual usage, which they are not. Melanotan I is afamelanotide, a 13-residue linear analogue. Melanotan II is a cyclic seven-residue analogue — a different sequence, a different ring structure and a different molecular weight. Bremelanotide, catalogued here as PT-141, is a metabolite of Melanotan II and a distinct molecule again.

The spelling problem, and how this catalogue handles it

The literature writes the second compound with Roman numerals — Melanotan II — and almost nobody searching for it does. The forms people actually type are "Melanotan 2" and "mt2", by a wide margin over the Roman form, which barely registers at all in Canadian search data.

So the product page carries both spellings in its heading and registers "Melanotan 2", "mt2" and "mt ii" as alternate names in its structured data, while the catalogue keeps the literature's spelling as the product's name. Searching any of them here finds the same vial.

Supplied and tested like the rest of the catalogue

Each compound in this group is a lyophilised powder in a sealed vial, released against the same HPLC purity specification as every other lot, with the certificate for that lot in the box. The cyclic structure of Melanotan II makes its retention behaviour distinct from the linear analogues on a chromatogram, which is one of the ways identity is confirmed rather than assumed.