MOTS-c

Oxytocin is a 9-amino-acid hormone made in the hypothalamus, famous as the chemistry behind labor contractions, breastfeeding, and social bonding. As an injectable drug it is FDA-approved to induce labor and control postpartum bleeding, but the intranasal 'love hormone' versions sold for trust, anxiety, and autism are experimental and the human results are genuinely mixed. The hype runs well ahead of the evidence.

Kisspeptin is the master switch that tells your brain to start reproduction. It is a family of peptides (the full length is kisspeptin-54, with shorter active fragments KP-14, KP-13, and KP-10) made from the KISS1 gene, and it acts as the upstream trigger for the entire reproductive hormone cascade. It is not an approved drug, but it has been tested in real human trials for fertility, hypothalamic amenorrhea, and male hypogonadism, with promising early results.

Gonadorelin is a synthetic copy of natural GnRH (gonadotropin-releasing hormone), a 10-amino-acid peptide (pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2) that tells the pituitary to release LH and FSH. It is FDA-approved for evaluating pituitary function and has historical use in inducing ovulation. In the peptide world it is mostly used off-label to keep the testes working during testosterone replacement, and the catch is that timing matters enormously: pulse it and you stimulate, give it continuously and you shut the system down.

Leuprolide (brand name Lupron) is a synthetic GnRH agonist, a modified peptide about 20 times more potent than natural GnRH, and it is FDA-approved for advanced prostate cancer, endometriosis, uterine fibroids, and central precocious puberty. The clever part is counterintuitive: it works by overstimulating the GnRH system so hard that the pituitary shuts down sex hormone production. It is a real, long-established prescription drug, not a research peptide, and it carries meaningful side effects from the low-hormone state it creates.

Desmopressin (dDAVP) is a synthetic tweak of the natural hormone vasopressin, redesigned to keep the water-retaining effect while dropping most of the blood-pressure effect. It is a long-established FDA-approved drug used for central diabetes insipidus, bedwetting and nocturia, and certain bleeding disorders like von Willebrand disease and mild hemophilia A. This is settled medicine, not an experimental peptide, and its main real-world danger is straightforward: it can drop your blood sodium dangerously low if you drink too much fluid on it.

Octreotide is a synthetic eight-amino-acid mimic of the natural hormone somatostatin, the body's main 'off switch' for hormone secretion. It shuts down excess growth hormone, so it is a frontline FDA-approved drug for acromegaly, and it also tames the flushing and diarrhea of hormone-secreting carcinoid and other neuroendocrine tumors. This is real, approved medicine with decades of clinical data behind it, sold as Sandostatin (injectable, since 1988), Sandostatin LAR (monthly depot), and Mycapssa (oral capsule, approved 2020).