Library / Hormonal

Follitropin

Also known as FSH, Follitropin alfa, Gonal-f, Ovaleap, Puregon, Follistim

Approved medicine

Recombinant follicle stimulating hormone (a glycoprotein, not a small peptide). Approved for ovarian stimulation and some male fertility indications.

Prescription medicine. Only a prescriber can decide whether a medicine suits you and at what dose. This page is information, not a recommendation.

Background

Recombinant human follicle stimulating hormone (FSH), a glycoprotein hormone produced in Chinese hamster ovary cells and identical in structure to natural FSH. Brands include Gonal-f (EMD Serono, known as Merck outside North America) and Puregon or Follistim (Organon).

How it is thought to work

It acts like the body's own FSH, stimulating follicles in the ovaries to grow, or supporting sperm production in men with low gonadotrophin levels when given with hCG.

What is claimed, and the evidence

Claim	Evidence	Notes
Ovulation induction in women who do not ovulate regularly	Approved use	FDA and TGA approved indication.
Growing multiple follicles for IVF and other assisted reproduction	Approved use	FDA and TGA approved indication.
Starting sperm production in men with hypogonadotropic hypogonadism	Approved use	Approved for Gonal-f, given with hCG.

Side effects

Effect	How often	Notes
Headache	Common	10 to 13% in label trials.
Ovarian cysts	Common	14% in the ovulation induction trial.
Abdominal or pelvic pain, nausea, bloating	Common	About 5 to 8%.
Ovarian hyperstimulation syndrome Serious	Common	7% in the ovulation induction trial; severe cases need hospital care.
Blood clots, lung complications, ovarian torsion Serious	Rare	Label warnings.
Multiple pregnancy, ectopic pregnancy, miscarriage Serious	Uncommon	Risks linked to fertility treatment.
Acne, breast enlargement and injection site pain in men	Common	Most common reactions in men treated for low sperm production.

Warnings

Ovarian hyperstimulation syndrome can be serious; treatment needs specialist monitoring.
Increased risk of multiple pregnancy and blood clots.
Serious allergic reactions including anaphylaxis can occur.

Regulatory status

Australia: Approved (ARTG, multiple brands).
United States: FDA approved (Gonal-f, Follistim AQ) for ovulation induction and assisted reproduction.

Sources

Also in Hormonal

From the VialOwl library, reviewed 26 September 2026. For education and general information. It is not medical advice and not a recommendation to use Follitropin.