Trinity compound research profile
PT-141
PT-141 (also called bremelanotide, brand name Vyleesi) is a lab-made peptide of 7 amino acids, chemically related to Melanotan II — it's actually one of...
Research overview
PT-141 (also called bremelanotide, brand name Vyleesi) is a lab-made peptide of 7 amino acids, chemically related to Melanotan II — it's actually one of the natural breakdown products (a metabolite) that forms when MT-II is processed by the body. It was specifically developed and FDA-approved as a treatment for low sexual desire in women (FDA Vyleesi label).
Mechanism under study
Like MT-II, PT-141 activates several of the same 'melanocortin' receptors scattered around the body and brain. Scientists don't fully know exactly how this leads to increased sexual desire — the FDA label itself says the mechanism is unknown — but it's believed to work through brain pathways rather than acting directly on blood flow the way erectile dysfunction pills like Viagra do (FDA label; King et al.).
Human evidence summary
Two large, well-designed twin trials (called RECONNECT, involving 1,267 women total, lasting 24 weeks) found that PT-141 improved measures of sexual desire and reduced related distress compared to placebo, with results considered statistically real but modest in size — meaning the improvement was measurable but not dramatic for most women (Kingsberg et al., Obstet Gynecol 2019). In a longer follow-up study, only about 40% of participants stuck with the extended year-long open-label phase, suggesting many women didn't feel it was worth continuing (Simon et al.). Separately, in men with erectile dysfunction, an earlier study using a nasal spray version showed improved erection quality and questionnaire scores, but this use was never approved by the FDA (King et al.).
Preclinical evidence summary
In rats, the peptide activates a specific brain area (the paraventricular nucleus) and triggers erections, supporting the idea that its effects run through the brain rather than directly on blood vessels (King et al.).
Source material
Use the linked publications and records to evaluate study design, population, limitations, and relevance.