Understanding FSH: Normal vs Optimal Ranges

?What is FSH?

FSH (follicle stimulating hormone) is produced by the pituitary gland and stimulates follicle development in women's ovaries and sperm production in men's testes. In women, FSH levels vary dramatically throughout the menstrual cycle and are a key marker of ovarian reserve (egg supply).

!Why It Matters

Elevated FSH in women — particularly early in the cycle (days 2–5) — indicates diminished ovarian reserve (fewer remaining eggs) and is used to evaluate fertility. Very high FSH with low oestradiol indicates menopause or premature ovarian insufficiency. In men, elevated FSH indicates testicular failure affecting sperm production.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• Elevated FSH (women): may indicate reduced fertility, approaching menopause
• Low FSH (men/women): hypogonadotropic hypogonadism — the pituitary is not adequately stimulating the gonads

How to Improve Your Levels

• 1Cannot directly lower FSH — it is a compensatory response to gonadal insufficiency
• 2Fertility treatments may be needed if FSH is elevated and conception is desired

When to Test

Test on day 2–3 of menstrual cycle for fertility assessment. Interpret alongside LH and estradiol.

Related Biomarkers