PT-141

What it is

PT-141 is a melanocortin receptor agonist — it works on the brain's arousal pathways rather than on blood flow (the route Viagra-class drugs take).

It is FDA-approved as Vyleesi for premenopausal women with hypoactive sexual desire disorder. Off-label and grey-market use spans both sexes.

History

Developed as a derivative of melanotan II — researchers noticed the sexual response effect and split it into its own drug. Approved as Vyleesi in 2019.

How it works

Activates MC3R/MC4R melanocortin receptors in the brain, increasing sexual desire and arousal centrally.

Dosage

• 0.5–1.75 mg, taken ~45 minutes before sexual activity.
• Most users start at 0.5 mg and increase if needed.
• No more than 8 doses per month is the approved guidance.

How it is taken

• Subcutaneous belly injection ~45 min before sexual activity.

How to reconstitute

• 10 mg vial with 2 ml BAC water = 5 mg/ml. 1 mg = 20 units on a 1 ml insulin syringe.

How it should arrive

White powder, sealed vial.

How it should look once reconstituted

Clear colourless solution.

What to expect, and when

• Effect window: starts ~30–45 min after dosing, lasts 4–8 hours.

Side effects

• Nausea — common.
• Facial flushing.
• Headache.
• Temporary darkening of skin / freckles at higher doses (same melanocortin mechanism as MT-II).
• Increased blood pressure for several hours — significant for anyone with hypertension.

Risks

• Not recommended for people with uncontrolled high blood pressure or known cardiovascular disease.
• Same theoretical mole-darkening concern as MT-II (smaller risk because of less frequent dosing).

Potential gains

• Increased sexual desire and arousal.
• Works on the central pathway, so it can help in cases where Viagra-class drugs cannot.

Other useful information

Works on libido (the wanting). Viagra-class drugs work on physical erection (the ability). They are not interchangeable — some users combine them, others find one sufficient.