Sexual & Reproductive Health Peptides
Research peptides involved in sexual function, libido, reproductive hormone regulation, and fertility — including melanocortin agonists and GnRH analogs.
Sexual & Reproductive Health Peptides
This category covers peptides researched for their effects on sexual function, libido, reproductive hormone signaling, and fertility. These peptides act through melanocortin receptors, GnRH pathways, kisspeptin signaling, and gonadotropin regulation.
Complete Peptide Directory
Sexual Function Peptides
| Peptide | Description | Primary Mechanism |
|---|---|---|
| PT-141 (Bremelanotide) | Melanocortin agonist FDA-approved (Vyleesi) for hypoactive sexual desire disorder | MC3R/MC4R activation; central nervous system sexual arousal pathways |
| PT-141 Nasal | Intranasal formulation of PT-141 for improved convenience | Same melanocortin mechanism with nasal delivery route |
| Bremelanotide | Generic name for PT-141; cyclic heptapeptide melanocortin agonist | MC3R/MC4R agonist; HSDD and erectile dysfunction research |
| Melanotan 2 | Non-selective melanocortin agonist with tanning and sexual function effects | MC1R (tanning), MC3R/MC4R (sexual arousal), MC5R (sebaceous) |
| Oxytocin | Neuromodulator of social bonding, sexual arousal, and orgasm | Oxytocin receptor; pair bonding, sexual function, labor induction |
Reproductive Hormone Regulation
| Peptide | Description | Primary Mechanism |
|---|---|---|
| Kisspeptin-10 | Master regulator peptide of GnRH neuron firing and reproductive axis | KISS1R agonist; puberty onset, hypothalamic amenorrhea, IVF research |
| Kisspeptin-54 | Full-length kisspeptin with sustained GnRH stimulation | KISS1R agonist; longer-acting reproductive axis activation |
| Gonadorelin | Synthetic GnRH that stimulates pulsatile LH and FSH release | GnRH receptor agonist; hypogonadism diagnosis, fertility stimulation |
| GnRH | Endogenous gonadotropin-releasing hormone from hypothalamus | GnRH receptor; master regulator of reproductive hormone cascade |
| LHRH | Luteinizing hormone-releasing hormone (identical to GnRH) | GnRH receptor; pulsatile gonadotropin release |
| Nafarelin | Synthetic GnRH agonist with enhanced potency for hormonal suppression | GnRH receptor agonist/desensitizer; endometriosis, precocious puberty |
| Buserelin | Long-acting GnRH agonist for reproductive hormone modulation | GnRH receptor agonist; prostate cancer, endometriosis, IVF |
| Triptorelin | Depot GnRH agonist for sustained gonadotropin suppression | GnRH receptor agonist; prostate cancer, precocious puberty, endometriosis |
| Insulin-Like Peptide 3 | Leydig cell hormone involved in testicular descent and fertility | RXFP2 receptor; gubernaculum development; testosterone signaling |
Common Research Themes
Melanocortin Pathway: PT-141 and Melanotan 2 both act through melanocortin receptors, but PT-141 was specifically developed to isolate the sexual function effects from the tanning effects of MT-2. PT-141 is FDA-approved (as Vyleesi) for premenopausal HSDD.
Kisspeptin-GnRH Axis: Kisspeptin sits upstream of the entire reproductive hormone cascade. It activates GnRH neurons, which release GnRH (gonadorelin), which stimulates LH/FSH from the pituitary. This makes kisspeptin a key research target for understanding and modulating fertility.
GnRH Agonist Paradox: Short-term GnRH agonist exposure stimulates gonadotropins, but sustained exposure (Nafarelin, Buserelin, Triptorelin) paradoxically suppresses them through receptor desensitization — the basis for their use in hormone-dependent conditions.
Central vs. Peripheral Action: PT-141 and Oxytocin act centrally (brain) to modulate sexual function, while Gonadorelin and Kisspeptin act on the hypothalamic-pituitary-gonadal axis, and Insulin-Like Peptide 3 acts peripherally on reproductive tissues.
Getting Started
If you are new to this category, we recommend starting with PT-141 — FDA-approved (as bremelanotide/Vyleesi) for hypoactive sexual desire disorder with a well-characterized mechanism. From there, explore related peptides through the See Also sections on each page to build a comprehensive understanding of the research landscape.
Pain & Nociception Peptides
Research peptides involved in pain signaling, nociceptive modulation, analgesic pathways, and neuroinflammatory pain conditions.
Russian Bioregulator Peptides
The complete Khavinson family of short peptides — organ-specific bioregulators that modulate gene expression in targeted tissues, developed at the St. Petersburg Institute of Bioregulation and Gerontology.