Neuroendocrine
Melanocortin signalling
Melanocortin peptides and analogues activate members of the MC1R–MC5R receptor family, influencing pigmentation, energy balance and central pathways relevant to sexual desire.
Biological pathway
Melanocortin receptor activation → G-protein signalling → cAMP-dependent effects in target cells and central neural circuits.
Evidence summary
Bremelanotide is an approved melanocortin receptor agonist for a restricted HSDD indication in the United States, although the precise mechanism by which it improves sexual desire is not established.
Limitations
Receptor selectivity and downstream effects vary by compound. MC1R activation contributes to pigmentation effects, and the therapeutic mechanism for HSDD remains incompletely defined.