PT-141 (Bremelanotide)
FDA-approved melanocortin receptor agonist derived from melanotan II research.
Also known as: Bremelanotide, Vyleesi
Bremelanotide, developed as PT-141, is a melanocortin receptor agonist that was approved by the FDA in 2019 as Vyleesi for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women. It is a refined successor to melanotan II with a different receptor selectivity profile.
Key facts
- Class
- Melanocortin receptor agonist (favoring MC4R)
- Originator
- Palatin Technologies
- Regulatory status
- FDA approved as Vyleesi (2019) for premenopausal HSDD
- Predecessor
- Developed from melanotan II research
- Administration in approved use
- Single-use subcutaneous autoinjector prior to anticipated activity
What is PT-141?
PT-141 is a development code name for bremelanotide, a synthetic cyclic peptide derived from earlier academic research on melanotan II. Palatin Technologies advanced bremelanotide through clinical development as a centrally acting treatment for sexual dysfunction, and the FDA approved it in 2019 under the brand name Vyleesi for acquired, generalized hypoactive sexual desire disorder in premenopausal women.
It is one of the few melanocortin-family peptides to reach FDA approval. The only others are afamelanotide for erythropoietic protoporphyria and setmelanotide for specific rare obesity syndromes.
Mechanism of action
Bremelanotide is a nonselective agonist with activity at multiple melanocortin receptors, but is more selective for MC4R than its predecessor melanotan II. The central activity at MC4R in brain regions associated with sexual arousal is believed to drive its effects on sexual desire. The compound does not act through vascular mechanisms like PDE5 inhibitors (sildenafil, tadalafil) and has a different onset and duration profile.
- •Acts centrally at melanocortin-4 receptors (MC4R) in brain regions involved in sexual arousal
- •Does not require an erection mechanism or vascular dilation to exert effects
- •More selective for MC4R than the parent compound melanotan II
- •Produces a different adverse event profile than PDE5 inhibitors
Clinical trial history
The RECONNECT studies, two phase 3 trials in premenopausal women with acquired, generalized HSDD, were published in Obstetrics and Gynecology in 2019. These trials supported the FDA approval of Vyleesi. Primary endpoints included validated sexual desire and distress measures, with bremelanotide showing statistically significant improvements compared with placebo.
Earlier clinical research on PT-141 explored its use in male erectile dysfunction, but the program in that indication was discontinued in favor of the female HSDD indication that eventually received approval.
Safety and regulatory context
The Vyleesi prescribing information lists nausea as the most commonly reported adverse event, along with flushing, injection site reactions, headache, and vomiting. The label includes a warning about transient blood pressure increases, and notes that the drug is contraindicated in patients with uncontrolled hypertension or known cardiovascular disease.
Bremelanotide is a prescription medication in the United States. Material sold as research PT-141 is intended strictly for laboratory use and is not cleared for off-label human administration.
Research sourcing
PT-141 (Bremelanotide) is listed by our research partner, GLP1 Research Lab, which supplies lyophilized peptides for laboratory use. Listings include product identifiers relevant to research documentation.
View PT-141 (Bremelanotide) listing at GLP1 Research LabAffiliate partnership. Metabolic Playbook may earn a commission on purchases made through this link at no additional cost to the researcher.