Follicle-Stimulating Hormone (FSH)

A pituitary hormone that drives egg development in women and sperm production in men. It is read alongside LH rather than on its own, and in women the number only means anything once you know where you are in your cycle.

Follicle-Stimulating Hormone in the Biomarker Guide — what it is, why it is tested, and what moves the number.

Add-on markers can only be added to venous samples.

Timing

In women, cycle day matters: days 2–5 is standard. In men, take between 7am and 10am.

Turnaround: the lab reports this test within 24 hours of receiving your sample, counted in working days. Most samples reach them within about 3 days of posting. Full detail on our Turnaround Times page.

We do not interpret results. Not medical advice or a diagnosis.