Reference
What is Melanotan II?
Melanotan II is a cyclic peptide — the chain is joined into a ring rather than left with two free ends. Cyclisation is a common strategy in peptide design because a closed ring is harder for enzymes to take apart than an open chain.
Classification
| Type | Peptide |
| Chain length | 7 amino acid residues |
| Family | Cyclic alpha-MSH analogue |
| Origin | Developed at the University of Arizona from the 1980s, alongside Melanotan I |
| Supplied as | Lyophilised powder in a sealed vial |
It is shorter than Melanotan I and structurally distinct, despite the shared name. PT-141 was derived from it later, which makes Melanotan II the parent of another compound in this range.
Where it sits by length
At 7 residues, Melanotan II is a short chain — an oligopeptide by the usual convention. The boundary is a convention, not a rule of chemistry — chains up to roughly fifty residues are generally called peptides.
What this page does not cover
Nothing here describes what Melanotan II does, what it is used for, or whether it is safe. We publish analytical results and ship parcels; we give no guidance on dosing, preparation or use, and that applies to our reference pages as much as to the product pages. The person to ask about any of that is a registered prescriber.
Related by family
Where it came from
Melanotan II followed Melanotan I out of the same Arizona programme, built on a different idea: make the chain shorter and tie it into a ring.
The late 1980s — University of Arizona, Tucson. When was Melanotan II created?
Further reading
Melanotan I vs Melanotan II — a chain and a ring from the same lab, and why only one became a medicine.
More on Melanotan II
- Melanotan II — prices and sizes
- Buying Melanotan II in New Zealand
- When was Melanotan II discovered?
See Melanotan II in the range · What is a peptide? · Discovery timeline · All reference
