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If you are a woman aged 45 or over, you usually do not need an FSH test. At that age, a high FSH is a normal sign of perimenopause and the menopause.[1]
On this page you can read what FSH is, what the guidelines say about a value that is too low or too high, what affects your value and which other values are best to look at alongside it.
Also known as: follitropin, follicle-stimulating hormone, pituitary gonadotropins. At the lab: FSH.
FSH stands for follicle-stimulating hormone. A hormone is a messenger in your blood that controls how certain cells or organs work. The pituitary gland makes FSH. The hypothalamus, a part of your brain, decides how much.[1]
In women who menstruate, FSH helps control the cycle. It starts the growth of eggs in the ovaries and gets them ready for ovulation. In men, FSH helps decide how much sperm the testes make and how healthy it is.[1]
In children, FSH is normally low until puberty begins. After that it rises, together with other hormones. That rise sets off the physical changes of puberty.[1]
In women, the test can help find the cause when trying for a child is not working, or when periods are irregular or have stopped. It can also show whether perimenopause or the menopause may have started.[1]
In men, the test can help find the cause when trying for a child is not working or when the sperm count is low. According to the source, you may need the test if you have not succeeded after 12 months of trying.[1]
In children and teenagers, the test mainly shows whether a medical cause lies behind early or late puberty. Early means signs of development before age 8 in girls and before age 9 in boys. Late means no signs by age 13 in girls and by age 14 in boys.[1]
For FSH, the lab uses a reference range of 1.0 to 12.0 U/L. The lab calls a level within those limits normal.[2]
| FSH | What it can mean | Who it is for |
|---|---|---|
| Low[1] | Normal until puberty begins | Children |
| Rising[1] | Part of the start of puberty | Children and teenagers |
| Varies throughout the month[1] | Normal, which is why testing is sometimes done on a set day of the cycle | Women who menstruate |
| High[1] | A normal sign of perimenopause and the menopause | Women aged 45 or older |
| Higher than expected[1] | May point to a condition of the ovaries or testes, or one outside them, that affects how they work | Women and men |
| Abnormal[1] | May point to a problem with the pituitary gland, the hypothalamus or the sex glands | Women and men |
Source: MedlinePlus, U.S. National Library of Medicine. General information for women, men and children, with no reference limits given as numbers.[1]
In children, a low FSH is normal until puberty begins. In adults, an abnormal level, including one that is too low, may point to a problem with the pituitary gland or the hypothalamus. Your doctor also looks at LH and other hormones.[1]
A high FSH may point to a condition of the ovaries or testes that means they make too few sex hormones. The pituitary gland then makes more FSH to try to get them working. In women around the menopause, though, a high FSH is a normal sign.[1]
BioProfile is working on its own zones for each value, from risk to optimal. A doctor reviews those zones before they appear in your result.
In women who menstruate, FSH changes over the course of the month. That is why you sometimes need to be tested at a particular point in your cycle.[1]
FSH is low in childhood and rises at puberty. Around perimenopause FSH rises again, because the ovaries release fewer eggs and your body makes more hormones to trigger ovulation.[1]
FSH depends on an interplay between the hypothalamus, the pituitary gland and the ovaries or testes. The sex hormones they make tell the brain when to start or stop making FSH. A problem in any of these parts can change your FSH.[1]
FSH is included in BioProfile 121 and 150.[3]
The BioProfile editorial team wrote this page on 10 October 2026 from the sources below, which we read on 10 October 2026. Every number on this page appears in one of those sources, with that source's number next to it. An expert has yet to check this page; after that check, the expert's name and the date of the check will appear at the top. This page offers explanation, not a diagnosis. Discuss a value outside the range with your GP.
