Gonal-F vs. Follistim: Key Differences, Cost & Success Rates Explained
Gonal-F and Follistim are both injectable gonadotropins—brand-name follicle-stimulating hormone (FSH) drugs used in fertility treatments to grow multiple eggs during IVF or ovulation-induction cycles.
Patients and even clinics swap the names because both arrive in similar pen devices, cost thousands, and are prescribed for the same purpose; a pharmacy benefit may cover one and not the other, so the choice often feels like a coin flip.
Key Differences
Gonal-F uses follitropin alfa manufactured in Chinese-hamster ovary cells, while Follistim is follitropin beta expressed in E. coli. Both have identical FSH activity but differ in packaging: Gonal-F comes in multidose pens or vials; Follistim AQ is single-use or 300-900 IU cartridges. Side-effect profiles overlap, yet some clinics report slightly higher local-site reactions with Follistim. Price per 300 IU: Gonal-F ~$310, Follistim ~$330.
Which One Should You Choose?
Let insurance and supply decide first. If coverage is equal, pick whichever your clinic has in stock—physicians are comfortable adjusting dose rather than brand. Studies show no significant difference in live-birth rates; success hinges more on your protocol and response monitoring than the pen label.
Can I switch mid-cycle?
Yes, with physician guidance; dose is recalculated in international units, so the switch is seamless.
Are generic versions available?
Gonal-F has an FDA-approved follow-on (Bemfola); Follistim currently has no direct generic, only biosimilar competition abroad.