A melanocortin receptor agonist, FDA-approved as Vyleesi for premenopausal women with low sexual desire (HSDD), and used more broadly off-label as a research peptide.
Reviewed for accuracy · Last reviewed July 7, 2026PT-141, or bremelanotide, is a melanocortin receptor agonist. Unlike erectile-dysfunction drugs that act on blood flow, it works centrally: through the melanocortin-4 receptor in the brain, it influences sexual desire and arousal rather than the vascular response. In one placebo-controlled imaging study it enhanced sexual brain processing and increased self-reported desire for up to 24 hours.
It is genuinely FDA-approved, as Vyleesi (2019), but for a narrow indication: acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, given as an as-needed subcutaneous injection. It is explicitly not indicated for postmenopausal women or men, so the broader use of PT-141 as a libido peptide across all groups is off-label and not covered by that approval.
The FDA-approved Vyleesi dose is 1.75 mg subcutaneously as needed, at least 45 minutes before activity, no more than one dose per 24 hours and eight per month. That is the only regimen with a label behind it.
Read the full PT-141 dosage guide →The most common reactions are nausea, flushing, injection-site reactions, and headache, mostly mild to moderate. The label also flags a transient rise in blood pressure and fall in heart rate after dosing.
Read the full PT-141 side effects guide →The approved Vyleesi product is a prefilled autoinjector. For research vials, keep the unmixed powder refrigerated and away from light, and store the reconstituted solution refrigerated. See the full storage & safety guide for handling and disposal basics.
This page is an independent educational reference and is not medical advice. Talk to a doctor before starting any compound.