PT-141 vs Melanotan II

A melanocortin receptor agonist FDA-approved as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. Increasingly used off-label by men for libido and arousal.

A synthetic analogue of alpha-MSH that stimulates melanin production in the skin, giving a deep tan with minimal sun exposure. Also has side effects on sexual function and appetite.

PT-141 (bremelanotide) activates central melanocortin receptors (MC3R/MC4R) rather than the vascular pathway targeted by PDE5 inhibitors like sildenafil. It acts on the brain's sexual-arousal circuitry.

Melanotan II is a non-selective melanocortin receptor agonist (MC1R, MC3R, MC4R, MC5R). MC1R activation drives melanogenesis; MC4R activation is what gives PT-141 its libido effect.

1.75 mg subcutaneous on demand

100 mcg daily loading, 250–500 mcg maintenance

~2 hours (effects persist longer)

~33 hours

Subcutaneous, Intranasal

Subcutaneous

approved

research-only

£20 · £2.0/mg via Peptides UK

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