Bremelanotide monograph

Bremelanotide

Overview

Bremelanotide is an FDA-approved injectable melanocortin receptor agonist used for hypoactive sexual desire disorder (HSDD) in premenopausal women. It is not a bodybuilding/performance drug in any evidence-based sense; its real use is sexual desire/arousal, and the effect is modest rather than dramatic. The evidence base for off-label performance or libido-enhancement use outside the approved population is thin.

Pharmacokinetics & Mechanism

• Class: Melanocortin receptor agonist peptide (synthetic cyclic heptapeptide)
• Mechanism of action: Bremelanotide is a melanocortin analog that activates central melanocortin pathways involved in sexual desire; it is thought to work primarily via CNS melanocortin receptors rather than by directly increasing peripheral genital blood flow like PDE5 inhibitors. Clinical literature describes it as a melanocortin receptor agonist that increases sexual desire and reduces distress related to low desire in some premenopausal women.
• Target(s): Primarily melanocortin receptors, especially MC4R and likely related CNS melanocortin pathways; exact human target contribution is not fully settled. It is not a testosterone agonist and is not a PDE5 inhibitor.
• Route(s) of administration: Subcutaneous injection only in approved labeling; not orally bioavailable. Community use is also typically subcutaneous.
• Onset: Clinical use is timed about 45 minutes before sexual activity; onset is therefore usually described as within that window, but exact onset is not well established.
• Half-life: Terminal half-life is about 2.7 hours in the FDA label/clinical pharmacology literature, with some secondary sources rounding to roughly 2.5–4 hours. There is no approved DAC or long-acting/extended-release variant; PT-141 and bremelanotide refer to the same short-acting peptide.
• Metabolism / clearance: Cleared mainly by hydrolysis and peptide catabolism with renal and nonrenal elimination; it is not primarily a CYP substrate in the way small-molecule drugs are. Human mass-balance and detailed clearance data are limited compared with standard oral drugs.