▶ PT-141 · SUBTOPIC · MECHANISM
PT-141 Mechanism
For Laboratory Research Use Only. The mechanistic information below is descriptive of published research. No human dose is recommended. No clinical claim is made.
MECHANISM OF ACTION
Synthetic alpha-MSH analog acting as melanocortin MC4R agonist on hypothalamic CNS pathways. FDA-approved as Vyleesi (2019). Mechanism via central melanocortin receptor activation; side-effect profile includes melanocyte stimulation.
PHARMACOKINETIC HALF-LIFE
Reported half-life for PT-141: 2.7 hours (subcutaneous). Half-life determines the kinetic window across which receptor occupancy is maintained and frames the dosing rhythm used in published literature.
PRIMARY SEQUENCE
PT-141 is a defined sequence: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH. Synthesis proceeds via solid-phase peptide synthesis with HPLC-verified identity confirmation.
MECHANISTIC OUTCOMES IN LITERATURE
The following outcomes are the mechanistic endpoints reported in the peer-reviewed literature, with GIGARESEARCH evidence grades. Grades reflect study quality and replication, not clinical recommendation.
RECONNECT-1 and RECONNECT-2 Phase 3 trials met primary endpoint (improvement in FSFI desire score); FDA approval June 2019.
Phase 2 trials showed efficacy in men with ED but Palatin pivoted to female HSDD for regulatory reasons.
MECHANISM Q+A
▶ What is PT-141?
PT-141 (bremelanotide, brand Vyleesi) is a cyclic 7-amino-acid peptide melanocortin 3/4 receptor agonist. FDA-approved June 2019 for hypoactive sexual desire disorder (HSDD) in premenopausal women.
▶ How does PT-141 differ from sildenafil?
PT-141 acts centrally on melanocortin receptors in the hypothalamus to drive arousal pathways (dopamine + oxytocin). Sildenafil acts peripherally on PDE-5 in the vasculature to facilitate erection. Different mechanism, different pathway.
CITED LITERATURE
- Kingsberg SA, Clayton AH, et al.. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol 2019. PMID 31022173. link
- Clayton AH, et al.. Bremelanotide for female sexual dysfunctions in premenopausal women. Womens Health (Lond) 2016. PMID 27193591. link
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▶ LAST UPDATED · 2026-05-19