Peptide Library
FDA-approvedMetabolicReviewed 2026-08-01

PT-141 (Bremelanotide)

aka Vyleesi · bremelanotide

A melanocortin receptor agonist approved for hypoactive sexual desire disorder in premenopausal women — a rare case of a 'lifestyle' peptide clearing full FDA review.

Mechanism of action

Activates MC4R (and MC1R/MC3R) in the central nervous system, increasing dopaminergic signaling in sexual-desire pathways rather than acting on vascular smooth muscle like PDE5 inhibitors.

Doses used in published studies

1.75 mg subcutaneously as needed, no more than once per 24 hours and 8 times monthly.

These figures describe what researchers administered under supervision. They are reported for accuracy and are not a protocol, recommendation, or substitute for clinical guidance.

Reported benefits

  • Statistically significant improvement in desire and distress scores in RECONNECT trials
  • On-demand rather than daily dosing

Risks & unknowns

  • Nausea in ~40% of users
  • Transient blood-pressure increase and heart-rate reduction
  • Focal hyperpigmentation with repeated use

Legal & regulatory status

FDA-approved 2019 as Vyleesi. Prescription-only; grey-market 'PT-141' vials are unapproved products.

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Key studies

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