Last updated: June 3, 2026
What PT-141 is
PT-141 (bremelanotide) is a synthetic 7-amino-acid cyclic peptide derived from alpha-melanocyte-stimulating hormone (α-MSH). Developed by Palatin Technologies. FDA-approved June 2019 as Vyleesi for premenopausal women with acquired generalized hypoactive sexual desire disorder.
Mechanism
PT-141 selectively activates melanocortin-4 receptor (MC4R) in the central nervous system. Unlike PDE5 inhibitors (sildenafil, tadalafil) that act on vascular tissue, PT-141 acts centrally on neural pathways governing sexual desire and arousal. The mechanism makes it functional in both men and women.
FDA-approved indication and dosing
- Vyleesi indication: Premenopausal women with acquired, generalized HSDD
- Dose: 1.75 mg subcutaneous injection, 45 minutes before anticipated sexual activity
- Maximum: 8 doses per month, no more than 1 dose in 24 hours
Side effects
Common (>10%): Nausea (~40% with first dose), flushing, injection-site reactions, headache.
Less common: Increased blood pressure (transient), hyperpigmentation of face/gums (~1% with regular use).
Contraindications: Uncontrolled hypertension, cardiovascular disease.
Comparison to sildenafil and tadalafil
PDE5 inhibitors act peripherally on vascular smooth muscle to enable erection. PT-141 acts centrally on neural desire pathways. They can theoretically be combined but PT-141 is not approved for erectile dysfunction.
Is PT-141 approved for men?<br />
No. FDA approval is for premenopausal women with HSDD. Off-label use in men exists but is not FDA-approved.
How fast does PT-141 work?<br />
Subcutaneous injection produces effects within 30-45 minutes. Duration ~12 hours.
Can PT-141 be combined with sildenafil?<br />
Different mechanisms suggest combination is possible, but combined use is not FDA-studied and adds cardiovascular risk.
What’s the most common side effect?<br />
Nausea, particularly with the first dose — affects ~40% of users.
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