Description
PT-141 (also Bremelanotide) is a synthetic cyclic heptapeptide derived from the metabolic profile of Melanotan-2. Unlike MT-2, PT-141 does not act primarily on pigmentation pathways but rather as a high-affinity agonist at melanocortin receptors MC3R and MC4R, with a particular focus on the MC4R pathway in the central nervous system.
In research, PT-141 ranks among the most-investigated compounds in the field of melanocortinergic mechanisms of sexual function. Unlike classical PDE-5 inhibitors that modulate vasodilation peripherally, PT-141 acts centrally via hypothalamic melanocortin receptor systems. In research models, effects on sexual arousal and libido were observed in both male and female subjects.
Nasal PT-141 was tested in early clinical studies in men: peak levels came after about 30 minutes and the half-life was about 2 hours (Diamond 2004). PT-141 is primarily renally cleared, with minimal plasma protein binding. In a crossover study in 19 men with erectile dysfunction, nasal PT-141 combined with low-dose sildenafil enhanced the erectile response compared with sildenafil alone (Diamond 2005).
Clinically, PT-141 received approval as Vyleesi in the US in 2019 for hypoactive sexual desire disorder in premenopausal women, as a self-administered subcutaneous injection. That makes the research database particularly robust compared to many other peptides, but the approval studies apply to the injection, not to the nasal spray. In addition to the primary sexual research applications, effects on appetite-regulating pathways and melanocortinergic stress response are also being investigated.
This variant is a ready-to-use nasal spray: 10mg of PT-141 dissolved in 5 ml saline and 0.4 ml bacteriostatic water (5.4 ml in total), nothing to mix yourself. One spray (0.1 ml) delivers about 185 mcg. A bottle lasts for about 50 sprays. It is made fresh once you place your order and ships as an express item. As a powder for reconstitution, PT-141 remains available in vials.
This information is for research and educational purposes only. No medical recommendations.
Risks & Safety
PT-141 has a comparatively robust clinical database through its approval as Vyleesi (subcutaneous), but per study reports it shows a defined side-effect profile via central melanocortin activation.
Documented in studies and user reports:
- Nausea: nausea is the most frequently documented observation following application and can be pronounced depending on the dose.
- Flushing and headache: facial flushing, warmth and headache are regularly described in the literature.
- Blood pressure changes: clinical studies documented transient blood pressure increases and a slight drop in heart rate, mostly transient.
- Pigment changes: through melanocortin activity, darkening of skin, moles or freckles is possible with repeated exposure.
- Nasal lining: the spray adds local effects: irritation of the lining, sneezing, a runny nose and a bitter taste in the throat when solution runs down the back.
This classification does not replace medical advice. Risk and responsibility for any actual use lie entirely with the buyer.
Studies
- Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction - International Journal of Impotence Research 2004: Double-blind, placebo-controlled phase 1 study of intranasal PT-141 in healthy men: plasma levels rose dose-dependently, the half-life was about 2 hours and the most common adverse events were flushing and nausea.
- Co-administration of low doses of intranasal PT-141, a melanocortin receptor agonist, and sildenafil to men with erectile dysfunction results in an enhanced erectile response - Urology 2005: Crossover study in 19 men with erectile dysfunction; nasal PT-141 combined with low-dose sildenafil enhanced the erectile response compared with sildenafil alone.
- Effect on Subjective Sexual Response in Premenopausal Women with Sexual Arousal Disorder - Journal of Sexual Medicine 2006: Classical study on the effect of intranasal PT-141.
- Bremelanotide: First Approval - Drugs 2019: Approval review of the subcutaneous form (Vyleesi, self-administered on demand), not of the nasal spray.
