Evidence memo / Reproductive & endocrine

Follitropin alfa

Also: Gonal-f · recombinant FSH · rFSH · follicle-stimulating hormone

Follitropin alfa (Gonal-f) is lab-made follicle-stimulating hormone (FSH), the pituitary hormone that tells the ovaries to grow eggs and supports sperm production. It is a backbone of fertility treatment, used to induce ovulation, to grow multiple eggs for IVF, and in some men to start sperm production. The Watchlist boundary is keeping it to monitored fertility use, with its ovarian-hyperstimulation and multiple-pregnancy risks, not as a general hormone or performance tool.

Approved for specific usesApproved specific useSafety / regulatory watch

The verdict

Our read at a glance.

Whether follitropin's benefit is understood as approved, monitored fertility treatment that stimulates egg or sperm development, rather than a general hormone or performance tool, and whether its ovarian-hyperstimulation and multiple-pregnancy risks are kept in view.

The signal
Decades of use and trials establish recombinant FSH as an effective way to induce ovulation and to stimulate the ovaries for IVF, working about as well as the older urinary-derived gonadotropins with more consistent purity.
The unknown
How best to tailor stimulation to each person to maximize success while minimizing ovarian hyperstimulation and multiple pregnancies, and how it compares with other gonadotropin products and protocols.
Our read
A well-established fertility medicine: lab-made FSH that reliably drives egg or sperm development, the workhorse of ovulation induction and IVF. The real considerations are careful monitoring to avoid ovarian hyperstimulation and multiple pregnancies, and matching the right product and protocol, not any general hormone or performance use.

The mechanism

How it works.

In the body, the brain's pituitary gland releases follicle-stimulating hormone (FSH), which travels to the ovaries to grow and ripen egg-containing follicles, or to the testes to support sperm production. Follitropin is lab-made FSH (grown in cells, then purified). Injected under the skin, it does the same job as natural FSH but at controlled, often higher levels: in women it drives one or several follicles to mature for ovulation or egg collection in IVF; in some men with too little of their own FSH, it helps restart sperm production. Because it pushes the ovaries harder than usual, the response has to be watched closely to avoid over-stimulation.

Safety & regulatory boundary

The consequential part.

The main risks are ovarian hyperstimulation syndrome (swollen ovaries and dangerous fluid shifts in severe cases), multiple pregnancies, blood clots, and ovarian torsion, so treatment is closely monitored with ultrasound and blood tests. Follitropin is a prescription fertility medicine used under specialist supervision, not a general hormone, anti-aging, or performance treatment. Recombinant follitropin alfa, follitropin beta, and urinary gonadotropins are related but distinct products.

What's next

What we're watching.

Individualized dosing to cut hyperstimulation and multiple-pregnancy risk, biosimilar and long-acting FSH products, and comparisons across gonadotropin protocols.

Context

Why this is discussed.

Follitropin is lab-made FSH, the pituitary hormone that tells the ovaries to grow eggs and supports sperm production. It is a backbone of fertility treatment, used to trigger ovulation or to grow multiple eggs for IVF, and in some men to start sperm production.

The evidence base

14 cited references.

Regulatory & labels1

DailyMed label: Gonal-f

EMD Serono, Inc. (FDA label) · 2025

Indexed literature (PubMed)11

Ovarian Stimulation Protocol in IVF: An Up-to-Date Review of the Literature

Pacchiarotti A et al. · Curr Pharm Biotechnol · 2016

The role of recombinant LH in ovarian stimulation: what's new?

Alviggi C et al. · Reprod Biol Endocrinol · 2025

Ovarian stimulation: today and tomorrow

Fatemi HM et al. · Curr Pharm Biotechnol · 2012

Pharmacogenetics of ovarian response

Lledo B et al. · Pharmacogenomics · 2014

Mild ovarian stimulation for IVF

Verberg MF et al. · Hum Reprod Update · 2009

FSH: urinary and recombinant

Palagiano A et al. · Eur J Obstet Gynecol Reprod Biol · 2004

Keep reading

Related published memos.