Gonadotropins are injectable fertility drugs used to stimulate ovulation in women or sperm production in men. They contain follicle stimulating hormone (FSH) and luteinizing hormone (LH) extracted from urine or produced through recombinant DNA technology. Gonadotropins act directly on the gonads to enhance fertility and are often used for ovarian stimulation in IVF cycles or for ovulation induction.

How Gonadotropins Work

Gonadotropins aim to mimic the body’s natural FSH and LH reproductive hormone function:

• In women, FSH stimulates the growth and development of ovarian follicles containing the egg cells. LH triggers ovulation.
• In men, FSH and LH act on cells in the testes called Leydig and Sertoli cells to stimulate sperm production and maturation.
• Gonadotropin injections provide additional FSH and LH to compensate when natural levels are deficient. This stimulates greater egg and sperm production.
• They are considered more potent than anti-estrogen drugs like clomiphene and letrozole.

Types of Gonadotropins

Common gonadotropin injectables include:

• Urofollitropin (Fertinex, Follistim AQ) – Purified urine-derived FSH
• Follitropin alfa (Gonal-F) – Recombinant DNA FSH
• Follitropin beta (Follistim AQ) – Recombinant DNA FSH
• Human menopausal gonadotropin (Menopur) – FSH and LH from urine
• Chorionic gonadotropin (Novarel, Pregnyl) – Urine hCG which mimics LH
• Lutropin Alfa (Luveris) – Recombinant LH

Uses and Procedures

Gonadotropins may be used for:

• Ovulation induction – Stimulating ovulation in anovulatory women. Requires monitoring to time intercourse or insemination when follicles mature.
• Controlled ovarian hyperstimulation – Developing multiple follicles for IVF. Given with a GnRH antagonist to prevent premature ovulation.
• Improving sperm count – Especially in men with hypogonadotropic hypogonadism. Requires monitoring for risks.
• Supplementing luteal function – hCG used to support the luteal phase.

Potential side effects include ovarian hyperstimulation syndrome, multiples pregnancy, and injection site reactions. Precise monitoring is required given the potency of these medications. But they can be highly effective when properly administered for specific fertility diagnoses.