Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study

J Urol. 1998 Aug;160(2):389-93.


Purpose: We evaluated the erectogenic properties of a new cyclic alpha-melanocyte-stimulating hormone analogue, Melanotan-II, to treat men with psychogenic erectile dysfunction.

Materials and methods: Ten men with erectile dysfunction of no known organic cause were entered in a double-blind, placebo controlled crossover study in which the erectogenic properties of Melanotan-II and a vehicle placebo were compared using real-time RigiScan monitoring. The presence, duration and rigidity of erections were recorded during a 6-hour period.

Results: In 8 of 10 men treated with Melanotan-II clinically apparent erections developed. Mean duration of tip rigidity greater than 80% was 38.0 minutes with Melanotan-II and 3.0 with placebo (p=0.0045). Transient side effects of nausea, stretching and yawning, and decreased appetite were reported more frequently after injections of Melanotan-II than placebo but none required treatment.

Conclusions: Melanotan-II is a potent initiator of erections in men with psychogenic erectile dysfunction and has manageable side effects at a dose of 0.025 mg./kg.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Abdominal Muscles
  • Adolescent
  • Adult
  • Appetite / drug effects
  • Cross-Over Studies
  • Double-Blind Method
  • Erectile Dysfunction / drug therapy*
  • Erectile Dysfunction / psychology
  • Humans
  • Injections, Subcutaneous
  • Male
  • Middle Aged
  • Monitoring, Ambulatory
  • Nausea / chemically induced
  • Penile Erection / drug effects*
  • Peptides, Cyclic / administration & dosage
  • Peptides, Cyclic / therapeutic use*
  • Pharmaceutical Vehicles
  • Placebos
  • Psychophysiologic Disorders
  • Time Factors
  • Yawning / drug effects
  • alpha-MSH / administration & dosage
  • alpha-MSH / analogs & derivatives*
  • alpha-MSH / therapeutic use


  • Peptides, Cyclic
  • Pharmaceutical Vehicles
  • Placebos
  • melanotan-II
  • alpha-MSH