(rFSH) Follicle stimulating hormone derived from genetic engineering instead of being extracted from the urine of postmenopausal women (human menopausal gonadotropin, or hMG) or from the pituitary glands of cadavers (human pituitary gonadotropin, or hPG). Produced and marketed by the two pharmaceutical companies Organon (as Puregon), or Fertinex in the US and Serono (as Gonal-F) to replace their hMG preparations. Has the advantage over hMG (and its purified derivatives) of being standard in biological structure and activity, and of not being of a human source (hPG -- but not hMG -- having been implicated in transmission of Creutzfeldt-Jakob disease).

Recombinant follicle stimulating hormone made by Organon. Called Puregon in Europe, Australia and Asia. On an equivalent dose basis, produces serum FSH that are somewhat slower to rise than with the use of hMG preparations, but which are ultimately higher: in other words, follicles and serum estradiol levels take a little longer to respond than they do to Humegon, but the number of mature, preovulatory follicles available for egg retrieval is the same or more. I find that 200 U (units) of Puregon per day produces a similar result to 225 U of Humegon or Metrodin. Generically known as follitropin beta.

Recombinant follicle stimulating hormone made by Serono. Generically known as follitropin alpha.

Human recombinant follicle stimulating hormone.

Called Fertinex in the US. Metrodin that has been highly purified by removing all contaminating urinary proteins and all luteinising hormone, and is thus similar in action to recombinant follicle stimulating hormone.

Recombinant follicle stimulating hormone made by Organon. Called Follistim in the US. Generically known as follitropin beta.

Recombinant follicle stimulating hormone made by Organon. Called Follistim in US. On an equivalent dose basis, produces serum FSH that are somewhat slower to rise than with the use of hMG preparations, but which are ultimately higher: in other words, follicles and serum estradiol levels take a little longer to respond than they do to Humegon, but the number of mature, preovulatory follicles available for egg retrieval is the same or more. Professor Jansen, medical director of SIVF, notes that 200 U (units) of Puregon per day produces a similar result to 225 U of Humegon or Metrodin. Generically known as follitropin beta.