Afamelanotide vs Bremelanotide
An implant that lets people with a rare sun-pain disease stay in daylight longer. Trials in 168 adults show it works for that, but none show it works for tanning. 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.
Afamelanotide has the stronger evidence, grade A (strong human evidence) against grade B for Bremelanotide. Both are FDA approved.
Evidence
AStrong human evidence
BSome human evidence
Human studies cited
Animal or cell studies cited
Why the grade
Two randomized, double-blind, placebo-controlled trials in 168 adults with EPP (94 in the United States, 74 in the European Union) showed more pain-free hours in sunlight, and a 117-patient post-authorisation cohort followed for about two years confirmed the effect in routine practice. Consensus guidelines recommend it for preventing phototoxic symptoms. The evidence is strong for EPP and nonexistent for the tanning use the compound is also known for.
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
FDA approved
Afamelanotide is FDA-approved and sold as Scenesse, a subcutaneous implant, approved in October 2019 to increase pain-free light exposure in adults with a history of phototoxic reactions from erythropoietic protoporphyria (EPP). The European Medicines Agency authorised it for the same disease in 2014.
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
Afamelanotide is best known as the first drug for EPP, a rare disease in which sunlight causes burning pain, and in its earlier life as a candidate 'sunless tan' because it darkens skin.
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
Randomized trials show it lengthens the time EPP patients can spend in sunlight without pain, which earns grade A for that indication; there are no trials supporting cosmetic tanning.
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
MC1R agonist
MC4R agonist
Route
Implant
Injection