Peptide Library

Activates melanocortin receptors (mainly MC4R) in brain regions involved in sexual arousal; it is not a blood-vessel drug like sildenafil

Activates the MC1R receptor on pigment cells, driving production of eumelanin (the dark, UV-protective pigment) without needing UV exposure; also antioxidant and anti-inflammatory effects in skin

Darkens skin through MC1R on pigment cells and, because it also hits brain melanocortin receptors, triggers erections, appetite loss, nausea and yawning

Fires the hypothalamic GnRH neurons, which release LH and FSH from the pituitary, which in turn drive testosterone or oestrogen and ovulation — it sits one step above GnRH in the reproductive axis

Signals the pituitary to release LH and FSH in a pulse; given in pulses it drives the gonads, given continuously it shuts them down

Acts as a long-lasting stand-in for LH at the LH/CG receptor: in men it drives the testes to make testosterone and supports sperm production; in women it triggers final egg maturation and ovulation and supports the corpus luteum

Contracts the uterus and milk ducts via the oxytocin receptor; in the brain, modulates social attention, bonding, stress and sexual response

Relaxes smooth muscle (blood vessels, airways, gut), stimulates secretion, and is one of the body's main anti-inflammatory and immune-balancing neuropeptides; in the lung it protects the surfactant-producing cells

Mimics humanin — binds a cell-surface receptor complex (CNTFR/WSX-1/gp130) and intracellular pro-apoptotic proteins (Bax, IGFBP-3), protecting cells from stress and death — but roughly 1,000 times more potent than the natural peptide in…

Cytoprotective and metabolic signalling similar to humanin — reduces apoptosis and oxidative stress, improves mitochondrial function and insulin sensitivity in rodents; recent work points to hypothalamic action and to chaperone-like effects…

Reported to restore age-declined melatonin secretion, normalise circadian hormone rhythms, raise antioxidant enzyme activity and, in the group's reports, lengthen telomeres — mostly from one research group over four decades

Membrane Klotho is the co-receptor for FGF23 (phosphate and vitamin D control); soluble Klotho acts hormonally — dampening insulin/IGF-1 and Wnt signalling, protecting against oxidative stress, and enhancing synaptic function in animals

Binds activin type II receptors (ActRIIA/B) with ALK4/5/7 and signals through SMAD2/3 — the same pathway as myostatin, which is why its effects on muscle are contested