PT-141
Melanocortin-receptor agonist; only FDA-approved peptide for sexual dysfunction.
- Primary research area
- Sexual function
- FDA status
- FDA approved 2019 (HSDD, women)
- Last updated
- Apr 21, 2026
- Reviewed by
- Peptide Examiner editorial team
What it is
PT-141 (bremelanotide, brand name Vyleesi) is a synthetic peptide melanocortin receptor agonist FDA approved in June 2019 for hypoactive sexual desire disorder (HSDD) in premenopausal women. It is one of a small number of FDA-approved peptide therapeutics and the only FDA-approved peptide for a sexual-function indication. It is administered as an on-demand subcutaneous injection prior to sexual activity.
Mechanism of action
PT-141 activates melanocortin receptors, particularly MC4R, in central nervous system pathways involved in sexual desire and arousal. This is mechanistically distinct from PDE5 inhibitors (sildenafil, tadalafil), which act peripherally on vascular smooth muscle to support erectile function. By acting centrally on desire pathways rather than peripheral blood flow, PT-141 targets the component of sexual dysfunction that vascular-acting drugs don't address.
Research history
Development spanned multiple indications before FDA approval in HSDD. Phase 3 trials (RECONNECT-1 and RECONNECT-2) in premenopausal women with HSDD demonstrated improvements in validated desire and distress measures. Development for male sexual dysfunction, hemorrhagic shock, and resuscitation have been studied but not approved.
Current trial status
FDA approved (June 2019) for HSDD in premenopausal women. Off-label use in men and postmenopausal women is common despite lack of specific FDA approval for those populations.
Regulatory status
FDA approved as Vyleesi (June 2019). Not on Category 2 list. Marketed by AMAG Pharmaceuticals (and subsequent commercial transfers). Full regulatory timeline →
Controversies and open questions
Side-effect profile is meaningful: nausea in 40% of users, flushing, and a characteristic temporary skin darkening due to off-target MC1R activation. Cardiovascular monitoring is recommended given transient blood pressure effects. The approved indication (premenopausal HSDD) is narrower than the off-label use case; evidence in men and postmenopausal women is less rigorous. Commercial uptake has been modest relative to vascular sexual-function drugs.
Further reading
Frequently asked
What's PT-141 FDA approved for?
Hypoactive sexual desire disorder (HSDD) in premenopausal women, approved June 2019 as Vyleesi. It's the only FDA-approved peptide for a sexual-function indication.
How is it different from Viagra?
Completely different mechanism. Sildenafil (Viagra) is a PDE5 inhibitor acting peripherally on vascular smooth muscle. PT-141 is a melanocortin receptor agonist acting centrally on CNS desire pathways. They target different components of sexual response.
Can men use it?
Off-label prescribing in men occurs, but the FDA approval is specific to HSDD in premenopausal women. Male sexual-function development programs were studied but not advanced to FDA approval.
What are the side effects?
Notable profile. Nausea in ~40% of users, flushing, transient blood pressure elevation, and a characteristic temporary skin darkening from off-target MC1R activation. Cardiovascular monitoring is recommended per the prescribing information.