Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction.
Level 2 - randomized trial
Randomized, double-blind, placebo-controlled crossover clinical trial
PubMed 11018622 · doi:10.1016/s0090-4295(00)00680-4
What was done
Ten men with organic erectile dysfunction participated in a double-blind, placebo-controlled crossover study. Participants received subcutaneous injections of Melanotan II (0.025 mg/kg) twice and vehicle (placebo) twice. Erections were assessed over a 6-hour period using real-time RigiScan monitoring and a visual analog scale. Sexual desire and side effects were evaluated via questionnaires.
What was found
Melanotan II elicited subjectively reported erections in 12 of 19 injections compared to 1 of 21 placebo injections. Among responders, the mean rigidity score was 6.9 out of 10. The mean duration of tip rigidity greater than 80% was 45.3 minutes for Melanotan II versus 1.9 minutes for placebo (P = 0.047). Sexual desire was significantly higher after Melanotan II administration than after placebo. Adverse effects were more frequent with Melanotan II, including stretching/yawning and nausea, with 4 of 19 Melanotan II injections resulting in severe nausea.
Why it matters
This study demonstrates that central melanocortin receptor stimulation with Melanotan II can induce erections and enhance sexual desire in men with organic causes of erectile dysfunction, not just psychogenic cases.
Limits
The study evaluated a very small sample size (n = 10 men), and only acute responses over a single 6-hour period per dose were monitored. Severe nausea occurred in 21% of active treatment administrations, posing tolerability concerns, and long-term efficacy and safety were not examined.
Cited by
- supports Melanotan II stimulates strong penile erections.