Melanotan II vs Bremelanotide
It is an injection sold for a deep tan, less appetite and better erections. The only study had 3 men, and the rest is case reports of harm, including changing moles. It is an injection for women who have low sexual desire. Two trials in 1,267 women found small gains on questionnaires, and about 40% of users felt sick.
Bremelanotide has the stronger evidence, grade B (some human evidence) against grade C for Melanotan II. Melanotan II: Not approved. Bremelanotide: FDA approved.
Evidence
CAnimal and cell studies
BSome human evidence
Human studies cited
Animal or cell studies cited
Why the grade
The human evidence is a 1996 pilot phase 1 study in three men, plus case reports of melanoma and changing moles in users. No controlled trial of Melanotan II has been published for tanning or any other use.
Approval rests on the two RECONNECT phase 3 trials, which randomized 1,267 premenopausal women and met their co-primary endpoints on desire and distress questionnaires. The effect sizes were small, the number of satisfying sexual events did not increase, dropout for nausea was high, and an independent reanalysis questioned the validity of the outcome questionnaires. Approved on RCTs but with surrogate questionnaire endpoints and contested benefit is grade B.
FDA
Not approved
Not approved by the FDA for any use and sold as an unregulated gray-market product. Melanotan II was nominated for the FDA's list of substances compounding pharmacies may use and placed in Category 2 (significant safety risk); the nomination was withdrawn and the FDA removed it from that category in April 2026, with an advisory committee review planned, which does not make it legal to compound or sell.
FDA approved
Bremelanotide is FDA-approved and sold as Vyleesi, a self-administered subcutaneous autoinjector, approved in June 2019 for premenopausal women with acquired, generalised hypoactive sexual desire disorder (HSDD). It is not approved for men or for postmenopausal women.
Sold for
Melanotan II is the 'Barbie drug' of gym and tanning culture, sold online as an injectable that gives a deep tan, suppresses appetite, and improves erections.
Bremelanotide is marketed as an on-demand injection for low sexual desire in women and is sold online, often as PT-141, as a libido booster for anyone.
Studies say
A three-man pilot study in 1996 showed it darkens skin and causes erections and nausea, and the rest of the literature is case reports of harm, which is grade C evidence.
Two randomized trials in 1,267 women showed statistically significant but small improvements in questionnaire scores for desire and distress, no increase in satisfying sexual events, and nausea in about 40% of users (grade B).
Class
Melanocortin agonist (MC1R/MC3R/MC4R)
MC4R agonist
Route
Injection
Injection