Highly purified Metrodin, with no residual luteinising hormone, thus equivalent in activity to recombinant FSH. Called Metrodin HP outside the US. Made by Serono.

(FSH) The hormone, or gonadotropin, produced by the pituitary gland that in women stimulates the tertiary follicle to grow; in men it stimulates spermatogenesis. Obtained from human sources in a mixture with luteinising hormone (LH) as (1) human menopausal gonadotropin (hMG), extracted from the urine of women who have been through the menopause (Humegon, Metrodin and Pergonal); and (2) human pituitary gonadotropin (hPG), from human pituitary glands removed at autopsies (now obsolete). Today, pure FSH is made synthetically with gene technology (recombinant FSH), such as Gonal-F and Puregon.

Generic name for recombinant FSH, as found in Gonal-F (or follitropin alpha) and Puregon (Follistim), or follitropin beta. Although there are slight differences in the two preparations, their clinical action is equivalent.