Follicle-stimulating hormone: reference ranges

In shortFor women who still menstruate the usual range is 4.7–21.5 IU/L; after menopause it rises to 25.8–134.8 IU/L. For adult men it is 1.5–12.4 IU/L. Before puberty levels are low in both sexes.

Reference ranges

Group	Reference range
Men, before puberty	0–5.0 IU/L
Men, during puberty	0.3–10.0 IU/L
Men, adults	1.5–12.4 IU/L
Women, before puberty	0–4.0 IU/L
Women, during puberty	0.3–10.0 IU/L
Women, still menstruating	4.7–21.5 IU/L
Women, after menopause	25.8–134.8 IU/L

Normal value ranges vary slightly among different laboratories, and some laboratories use different measurements or test different samples. In women who menstruate, the cycle day at the draw matters.

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A rough comparison with a typical range, not a diagnosis. Reference ranges vary between laboratories — check the range on your own report and let a clinician interpret the result.

What this marker is

Follicle-stimulating hormone (FSH) plays an important role in sexual development in children and fertility in adults. In women who menstruate, FSH helps control the menstrual cycle — it triggers the growth of eggs in the ovaries and gets them ready for ovulation. In men, FSH helps control how much sperm the testicles make and how healthy the sperm are. In children, FSH levels are normally low until puberty starts; then, in girls, FSH tells the ovaries to start making estrogen, and in boys it tells the testicles to start making testosterone.

For women, the test is used after 12 months of being unable to get pregnant, or when periods are irregular or have stopped. At age 45 or older testing usually is not needed, because high FSH is a normal sign of perimenopause and menopause — as the ovaries release fewer eggs, the body makes more hormone to try to trigger ovulation — but the test still helps with premature menopause (age 40 or younger), early menopause (before 45), unclear menopause-like symptoms, or reduced interest in sex. For men, the reasons are 12 months of being unable to get a partner pregnant, reduced interest in sex, a low sperm count, or loss of muscle and body hair. For both sexes, a suspected pituitary disorder is another reason — pituitary problems can cause fatigue, weakness, decreased appetite, and weight loss.

The usual ranges: men before puberty 0–5.0 IU/L, during puberty 0.3–10.0 IU/L, adults 1.5–12.4 IU/L; women before puberty 0–4.0 IU/L, during puberty 0.3–10.0 IU/L, while still menstruating 4.7–21.5 IU/L, after menopause 25.8–134.8 IU/L. Women who menstruate may need to be tested at a specific time in the cycle, because FSH levels change throughout the month.

In children with signs of early sexual development — before age 8 in girls or 9 in boys — high FSH and LH mean early (precocious) puberty, most often of unknown cause but sometimes from a brain tumor, a past brain injury, or a past brain infection; normal FSH and LH point to peripheral precocious puberty, usually a disorder of the testicles, ovaries, or adrenal glands raising estrogen or testosterone, and sometimes severe hypothyroidism or exposure to medicines containing sex hormones. In teens with no signs of sexual development by age 13 for girls or 14 for boys, low or normal FSH and LH usually mean delayed puberty.

When it is high

In women: menopauseDuring or after menopause — including premature menopause — FSH rises as the ovaries respond less to the pituitary's signal.

In women: other causesHormone therapy, certain types of tumor in the pituitary gland, and Turner syndrome can raise FSH.

In men: testicles not functioningDamage to the testicles from alcohol overuse, chemotherapy, or radiation; genetic problems such as Klinefelter syndrome; treatment with hormones; and certain pituitary tumors.

In childrenHigh FSH in boys or girls may mean that puberty is about to start — and with signs of early development, high FSH and LH together indicate precocious puberty.

When it is low

In womenBeing very underweight or having had recent rapid weight loss, not ovulating, pregnancy, and the pituitary gland or hypothalamus not producing normal amounts of hormones. Low FSH may also be linked to extreme exercise.

In menLow FSH may mean the pituitary gland or hypothalamus does not produce normal amounts of some or all of its hormones.

What can skew the result

These factors can shift the value without any disease — worth considering before a retest:

The day of the menstrual cycle — levels change throughout the monthHormone therapyBody weight: being very underweight, rapid weight loss, extreme exercisePregnancy

How to prepare

Women who have menstrual periods may need to be tested at a specific time during the cycle, because FSH levels change throughout the month. Beyond that, no special preparation is usually needed.

When a retest makes sense

FSH is read together with LH and estradiol — the combination separates ovarian or testicular causes from pituitary ones. In children, FSH and LH together sort out early and delayed puberty; in fertility workups, cycle-timed repeats are standard.

Who usually reviews this result

A result outside the reference range is usually reviewed by: a gynecologist or endocrinologist; a fertility specialist when infertility is the concern. Bring your lab report and any previous results to the appointment.

Names used on lab reports

Your report may use any of these names:
FSHFollitropinFollicle-stimulating hormone: serumPituitary gonadotropins

Units

Measured in: IU/L

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Frequently asked questions

Why is high FSH normal after 45?

As the ovaries release fewer eggs with age, the pituitary makes more FSH to try to trigger ovulation — so a high level is a normal sign of perimenopause and menopause, and testing is usually not needed at 45 or older unless there is a specific medical reason.

What do FSH and LH show together in children?

With signs of early sexual development, high FSH and LH mean central precocious puberty; normal levels point to a peripheral cause in the ovaries, testicles, or adrenal glands. With no development by age 13 for girls or 14 for boys, low or normal levels usually mean delayed puberty.

Can weight affect FSH?

Yes. In women, low FSH may be linked to being very underweight, recent rapid weight loss, or extreme exercise — the body deprioritizes reproduction when resources are scarce.

Sources

Follicle-Stimulating Hormone (FSH) Levels Test: MedlinePlus Medical Test — MedlinePlus, National Library of Medicine. Accessed: August 29, 2026.
Follicle-stimulating hormone (FSH) blood test: MedlinePlus Medical Encyclopedia — MedlinePlus, National Library of Medicine. Accessed: August 29, 2026.

Follicle-stimulating hormone