Category
Sexual Health
Peptides studied for libido, sexual function, and reproductive health.
Gonadorelin
Gonadorelin (synthetic GnRH decapeptide)
A synthetic decapeptide identical to endogenous GnRH. Triggers pituitary LH and FSH release. Previously FDA-approved as Factrel and Lutrepulse, both withdrawn. Currently used off-label on TRT to preserve testicular function. WADA-banned.
Kisspeptin
Kisspeptin (Kp-10, Kp-54)
Hypothalamic neuropeptide and master regulator of GnRH secretion; investigated for hypothalamic amenorrhea and sexual dysfunction.
Kisspeptin-54
Kisspeptin-54 (Metastin) — KISS1 Gene Product
54-amino-acid endogenous peptide hormone that activates the KISS1R receptor on hypothalamic neurons to drive GnRH release. Imperial College London has run Phase 2 trials in hypogonadism and infertility. No FDA approval.
Melanotan II
Melanotan II (MT-II)
Non-selective melanocortin receptor agonist used unregulated for skin tanning and libido; precursor to FDA-approved bremelanotide.
PT-141
PT-141 (Bremelanotide, Vyleesi)
Melanocortin receptor agonist FDA-approved June 21, 2019 (Vyleesi) for acquired generalized hypoactive sexual desire disorder in premenopausal women.
Sexual Health Peptides
Sexual health peptides are compounds studied for libido, arousal, erectile function, and reproductive endocrinology. The category is short and dominated by a single FDA-approved drug.
PT-141 (bremelanotide, Vyleesi) is a melanocortin receptor agonist FDA-approved in 2019 for premenopausal women with hypoactive sexual desire disorder. It acts centrally on MC4 and MC3 receptors rather than peripherally on vascular tissue. Two Phase 3 trials (RECONNECT) supported the approval. Off-label use in male erectile dysfunction sits outside the approved indication and trial dataset.
Kisspeptin is the master upstream regulator of gonadotropin-releasing hormone. Imperial College London has run an extensive translational research program for hypoactive sexual desire and hypogonadism, with Phase 2 data published since 2017. The compound is not yet FDA-approved.
Melanotan II (MT-II) is the unapproved predecessor to bremelanotide. Used as a tanning agent and libido enhancer in research-chemical markets. No regulatory approval exists in any major market. Adverse events include nausea, blood pressure changes, and melanocyte-driven mole darkening, with documented melanoma cases reported in case series.
Afamelanotide (Scenesse) is a melanocortin agonist FDA-approved in 2019 for erythropoietic protoporphyria. It is mechanistically related but not used for sexual health.
The category is small because few peptides have made it past Phase 1 for libido or erectile indications. The PDE5 inhibitor class (sildenafil, tadalafil) dominates pharmacotherapy for erectile dysfunction and is not peptide-based. PT-141 remains the only peptide entry with completed Phase 3 evidence.