Sexual and hormonal

PT-141 (bremelanotide) is a melanocortin receptor agonist, a cyclic peptide that acts on the MC4R receptor in the brain. In plain terms: it raises sexual desire through brain signaling rather than blood flow, which is different from how erection drugs work. It is FDA-approved for low libido in women.

Kisspeptin is a natural brain peptide that sits at the very top of the reproductive hormone chain, switching on the neurons that release GnRH. In plain terms: it kick-starts your body's own sex-hormone production, which is why it is studied for libido and fertility, with a gentler feel than PT-141.

Gonadorelin is synthetic GnRH, the hormone your brain uses to tell the pituitary to make testosterone and fertility hormones. In plain terms: it prompts your own hormone production, often used alongside testosterone therapy to keep the testicles active. Because it clears fast, it needs frequent dosing.

HCG (human chorionic gonadotropin) is a hormone that mimics LH, the signal that tells the testicles to make testosterone and sperm. In plain terms: it keeps the testicles switched on, commonly used alongside testosterone therapy or for fertility.

HMG (menotropin) is a fertility medication containing both FSH and LH, the two pituitary hormones that drive egg and sperm production. In plain terms: it supplies those signals directly to stimulate fertility, used in fertility treatment and sometimes with testosterone therapy.

Oxytocin is a natural 9-amino-acid hormone made in the brain, released during touch, closeness, and childbirth. In plain terms: known as the 'bonding hormone,' it is used as a nasal spray or tablet for connection, mood, and sometimes libido, with subtle, short-lived effects.

Testagen is a 4-amino-acid 'bioregulator' from the Russian Khavinson family. In plain terms: it is marketed for testicular function and testosterone with age, but there is very little real human research behind it.

Prostamax is a 4-amino-acid 'bioregulator' from the Russian Khavinson family. In plain terms: it is marketed for prostate support in older men, but there is very little real human research behind it.

Triptorelin is a synthetic analogue of gonadotropin-releasing hormone, the brain signal that tells the pituitary to release the hormones controlling the testes and ovaries. It is an approved medicine, marketed in the US as Trelstar and Triptodur.

PT-142 is a name sold next to PT-141 on the research market. In plain terms: PT-141 is a real, approved drug and no published source describes a distinct compound called PT-142.

Leuprolide is a GnRH agonist approved since the 1980s. In plain terms: it floods the switch that controls sex hormones until the switch stops responding, which shuts hormone production down.

Goserelin is a GnRH agonist delivered as a small implant placed under the skin of the abdomen. In plain terms: same hormone shutdown as leuprolide, delivered as a pellet that dissolves over weeks.

Cetrorelix is a GnRH antagonist used during IVF. In plain terms: it blocks the signal that would trigger ovulation, so eggs can be collected on schedule rather than lost early.

Degarelix is a GnRH antagonist approved for advanced prostate cancer. In plain terms: it drops testosterone immediately, without the surge that the older agonist drugs cause first.

Desmopressin is a modified version of vasopressin, the hormone that tells the kidneys to hold on to water. In plain terms: it reduces urine production, and it treats bleeding disorders too.

Enclomiphene is the trans-isomer of clomiphene, a selective estrogen receptor modulator that blocks estrogen feedback at the pituitary so LH, FSH and testosterone all rise. In plain terms: it stops the brain from seeing estrogen, so the brain tells the testicles to make more testosterone.

Clomiphene citrate is a selective estrogen receptor modulator supplied as a mixture of two isomers, enclomiphene and zuclomiphene, which have opposite effects at the estrogen receptor. In plain terms: it blocks estrogen feedback in the brain so ovulation is triggered in women, or so testosterone rises in men.

Tamoxifen is a selective estrogen receptor modulator that blocks estrogen in breast tissue while acting like estrogen in bone and the uterus. In plain terms: it blocks estrogen where breast tissue would respond to it, which is why it is used against breast cancer and against breast tissue growth in men.

Anastrozole is a non-steroidal aromatase inhibitor that blocks the enzyme converting androgens into estrogen, lowering circulating estrogen rather than blocking its receptor. In plain terms: it stops the body making estrogen in the first place, so estrogen levels fall.

Letrozole is a non-steroidal aromatase inhibitor that competitively binds the heme group of the aromatase enzyme, cutting estrogen production across every tissue that makes it. In plain terms: it shuts down estrogen production more completely than anastrozole does.

Toremifene is a selective estrogen receptor modulator closely related to tamoxifen, approved for metastatic breast cancer in postmenopausal women with estrogen receptor-positive or unknown tumours. In plain terms: it blocks estrogen in breast tissue much as tamoxifen does, and it also stretches out the heart's electrical cycle.

Cabergoline is an ergot-derived dopamine agonist with high affinity for the D2 receptor, approved for hyperprolactinaemic disorders that are either idiopathic or caused by a pituitary adenoma. In plain terms: it tells the pituitary to stop releasing prolactin, and prolactin drops.