Melanotan II vs PT-141

Name: Melanotan II vs PT-141
Published: 2026-10-24

Updated Oct 24, 20269 sources

Key differences

1Both are cyclic 7-amino-acid melanocortin agonists. MT-II hits MC1R, MC3R, MC4R and MC5R, so it tans, raises libido and cuts appetite at once.
2PT-141 (bremelanotide) favours MC3R/MC4R, tans little, and is FDA approved as Vyleesi for low desire in women. MT-II was never submitted for approval.
3PT-141 is used on demand; MT-II is loaded daily and then dosed weekly.
4Same melanocortin family. Melanotan II hits the receptors broadly and tans strongly.
5PT-141 was chosen to keep the sexual effect with less tanning, but dark patches still show up: 1% at label use, 38% after 8 daily doses.

Facts from each record, in the same words as their own pages.

Melanotan II and PT-141 side by side
	Melanotan II	PT-141
Category	Skin & hair, Sexual health	Sexual health
Evidence	Limited human data	Strong human trials
FDA status	Not FDA approvedRegulatory	FDA approved as VyleesiRegulatory
WADA	Not confirmed	Not confirmed
Half-life	About 33 minutes, per two guides. No primary human pharmacokinetic study was found.Competitor guide About 1 to 2 hours, per other guides; one says online 33-hour figures confuse the drug's half-life with how long its effects last.Competitor guide	About 2.7 hours (range 1.9 to 4.0) after a subQ shot, peaking around 1 hour. SubQ bioavailability is about 100%.Regulatory
Routes	Subcutaneous injection, Nasal	Subcutaneous injection, Nasal
Forms	Vial (powder), Nasal spray	Prefilled pen, Vial (powder), Nasal spray, Other form
Reported doses	0.01 to 0.03 mg/kg (subcutaneous injection) 50 to 1,000 mcg (subcutaneous injection) 0.1 to 1 mg (subcutaneous injection)	0.3 to 10 mg (subcutaneous injection) 7.5 to 20 mg (nasal) 500 to 1,500 mcg (subcutaneous injection)
Most cited frequency	Every other day, alternating with saline, Monday to Friday for 2 weeks	As needed. No more than 1 dose in 24 hours; more than 8 doses a month is not recommended.
Vial sizes	10 mgCompetitor guide	10 mgCompetitor guide
Mixed vial keeps	Keep the mixed vial at 2 to 8 C and out of light.Competitor guide	Keep the mixed vial at 2 to 8 C and do not freeze it.Competitor guide
Protocols on file	12	9

Doses shown are what sources report, labelled by origin. Not medical advice.

9 sources, each checked by date. Record updated Oct 24, 2026. Numbers are restated in our own words and labelled by where they came from.