Melanocortin receptor agonist
Bremelanotide
EstablishedAlso known as PT-141, Vyleesi
The FDA-approved libido peptide that skips the vascular route.
- Cited sources
- 1
- Human-tested claims
- 2 of 2
- Best evidence
- Tier 1 · Established
- Status
- Approved
A cyclic melanocortin-receptor agonist that acts centrally on sexual desire rather than on blood flow. It is FDA-approved (Vyleesi, 2019) for acquired hypoactive sexual desire disorder in premenopausal women, based on two Phase 3 trials. Structurally it is the near-twin of melanotan II — differing by a C-terminal acid.
How it works
Bremelanotide is a non-selective melanocortin agonist, but its therapeutic effect is attributed to central MC4R/MC3R activity in brain circuits governing sexual desire — a fundamentally different route from blood-flow drugs like the PDE5 inhibitors.
Sequence: Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OHA cyclic lactam heptapeptide with N-acetylation, non-natural Nle, and a D-Phe. It differs from melanotan II only by a C-terminal free acid (vs amide).
What it's studied for
One claim per card, each with its own tier and source. Tiers 1 and 2 are human data. Tiers 3 and 4 are not yet.
- [1]FDA label — Vyleesi (accessdata)(opens in a new tab)
FDA-approved for HSDD in premenopausal women, based on two Phase 3 trials (RECONNECT).
Established - [1]FDA label — Vyleesi (accessdata)(opens in a new tab)
Acts centrally as a melanocortin (MC4R/MC3R) agonist rather than on vascular blood flow.
Established
Safety & limitations
The label documents transient increases in blood pressure and decreases in heart rate after each dose, plus nausea and focal hyperpigmentation; it is not for people with uncontrolled hypertension or known cardiovascular disease.
[1]FDA label — Vyleesi (accessdata)(opens in a new tab)Regulatory & legal status
FDA-approved (Vyleesi, 2019) for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women.
[1]FDA label — Vyleesi (accessdata)(opens in a new tab)Frequently asked
How is bremelanotide different from melanotan II?
They share almost the same structure, but bremelanotide ends in a free acid and was refined toward central MC4R activity — becoming an FDA-approved drug. Melanotan II stayed broad-spectrum (including MC1R tanning), unapproved, and carries the safety concerns.
References
Written by Twenty Residues editorial. Medical review: pending; a named reviewer is being assigned.
Last updated September 19, 2026.
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Update history
- 2026-09-19 — Sourced review — every claim checked against primary literature; sequence, regulatory status, safety, and FAQs added.