What is FSH?
FSH, follicle-stimulating hormone, is the signal with which your brain sets the ovaries to work. The pituitary, a gland beneath your brain, releases it at the start of every cycle; it lets a group of follicles mature, and the winning follicle makes oestradiol. As soon as that oestradiol rises, the pituitary releases less FSH: a thermostat that regulates itself back down. In men FSH drives the production of sperm cells in the testes. That thermostat is the key to reading FSH. If the ovaries respond well, little FSH is needed and the number stays low. If they respond less, because the store of follicles is shrinking, the pituitary has to pull harder and FSH rises, years before periods stop. A high FSH is therefore not a hormone in excess, but a brain that has to call louder. Your report shows FSH in U/l, sometimes written as E/l, which is the same unit. In women there is a range per cycle phase, with the band for after the menopause apart, and that begins above the ceiling of every cycle phase. In men there is one range.
Why is FSH relevant?
In women FSH answers two questions. The first: how are the ovaries still responding? An FSH at the start of the cycle that climbs over the years shows that the store of follicles is shrinking, and after the menopause it stays permanently high. The second: if the cycle stays away, does that lie with the ovaries or with the signal from the brain? A high FSH with a low oestradiol points at the ovaries; a low or normal FSH with a low oestradiol points at the brain, and in young, sporty women that is almost always an energy deficit, overtraining, weight loss or stress. That second one matters most for anyone who wants to stay healthy. A missing cycle in a woman who trains a lot or eats little is not fitness but a body temporarily switching reproduction off to save energy, and bone pays for it. FSH and LH low, oestradiol low: that is the pattern, and it is reversible with food, rest and time. For diagnosing the menopause FSH is less suitable than it seems. In the years before it fluctuates from cycle to cycle, high one month and normal the next, so one measurement says little. The menopause is diagnosed on age, symptoms and the absence of periods, and a GP does not as a rule measure FSH for it. Anyone on the pill also measures a suppressed FSH. In men a high FSH says the testes are making fewer sperm cells, and that is a question with a wish for children; a low FSH together with a low LH goes with anabolic steroids, which shut the pituitary down.
FSH reference ranges
What counts beside the number:
- Your cycle day: at the start, day 2 to 5, FSH is easiest to compare
- LH, which comes from the same gland and usually sits in the same draw
- Oestradiol, the ovaries' answer: high FSH with low oestradiol is the ovaries, low with low is the signal from the brain
- Contraception, which suppresses FSH
- Your energy balance: food, training hours, weight loss and stress
- Your age and symptoms, because the menopause is not diagnosed on FSH
The bands above are where the labs overlap; the range on your own report may be slightly wider, and there is no national normal value. In the Netherlands the menopause is not diagnosed on FSH but on age, symptoms and the absence of periods, and a GP does not as a rule measure FSH for it. Pick the phase that applies to you.
What Dutch labs actually use
The four labs publish FSH not per age but per cycle phase, with the post-menopausal band apart. Star-shl writes its bands in E/l, the same unit as the U/l of the other three; only the spelling differs. Two of the four agree with each other exactly. Star-shl and Certe print the same figures for the four cycle phases and for men as well, down to the decimal. The most striking thing sits in the post-menopausal row. Where the four labs overlap, that band starts at 26.7 U/l, above the ceiling of every cycle phase: follicular the shared band stops at 8.1, around ovulation at 16.7 and luteal at 5.1. Inside one lab that separation need not exist, because Clinical Diagnostics lets its post-menopausal band start at 16.7 already, below its own ovulatory ceiling of 22.5. For men from 19 yrs the shared band runs from 1.5 to 12.0 U/l. Certe prints separate bands for 12 to 19 yrs, 0.9 to 9.1 for women and 0.9 to 7.1 for men, and those are in the table because that is how the lab publishes them.
3.8 – 8.1U/l
Between 3 and 3.8 and between 8.1 and 12.5 it differs per lab, because each lab sets its limits on its own method and population. Above 12.5 every lab calls it abnormal.
Every age, per lab
| Laboratory | Group | Reference range |
|---|---|---|
| Unilabs(Saltro, Medlon, SHO, Atalmedial)2026 | Follicular phase (from 14 yrs) | 3.0–8.1 U/l |
| Mid-cycle (from 14 yrs) | 2.6–16.7 U/l | |
| Luteal phase (from 14 yrs) | 1.4–5.5 U/l | |
| Post-menopausal (from 14 yrs) | 26.7–133 U/l | |
| Men from 20 yrs | 1.0–12.0 U/l | |
| Star-shl2026 | Men | 1.5–12.4 E/l |
| Women follicular phase | 3.5–12.5 E/l | |
| Women ovulatory phase | 4.7–21.5 E/l | |
| Women luteal phase | 1.7–7.7 E/l | |
| Women post-menopausal phase | 25.8–134.8 E/l | |
| Certe2026 | Women follicular phase (day 1–12) | 3.5–12.5 U/l |
| Women ovulation peak (day 13–15) | 4.7–21.5 U/l | |
| Women luteal phase (day 16–28) | 1.7–7.7 U/l | |
| Women post-menopausal | 25.8–134.8 U/l | |
| Men from 19 yrs | 1.5–12.4 U/l | |
| Women 12 to 19 yrs | 0.9–9.1 U/l | |
| Men 12 to 19 yrs | 0.9–7.1 U/l | |
| Clinical Diagnostics2026 | Men | 1.3–19.3 U/l |
| Women follicular phase | 3.8–8.8 U/l | |
| Women ovulatory phase | 4.5–22.5 U/l | |
| Women luteal phase | 1.8–5.1 U/l | |
| Women post-menopausal | 16.7–113.6 U/l |
Each band as the lab publishes it, retrieved in 2026, unless marked otherwise.
FSH high or low: what it means
A high FSH in women means the pituitary is pulling harder on the ovaries: permanently after the menopause, fluctuating in the years before, and with premature ovarian insufficiency already before the age of forty. Around ovulation FSH is temporarily higher than in the phases beside it; that is the rhythm, not a finding. In men a high FSH goes with testes making fewer sperm cells, after an infection, after chemotherapy or from a congenital cause. A low FSH is the ordinary picture in the second half of the cycle, and on the pill the intention. Beyond those, together with a low oestradiol and a missing cycle, it points at the signal from the brain: an energy deficit, overtraining, fast weight loss or stress, and rarely a problem of the pituitary itself. In men using anabolic steroids FSH falls silent together with LH, and with it their own sperm production. With a low FSH from an energy deficit the lever is the balance itself: enough food for what you burn, especially carbohydrates and fat, fewer training hours or more rest between them, more sleep, and no crash diet. The cycle usually returns within months, and FSH and oestradiol recover with it. A high FSH cannot be lowered with lifestyle: it is the ovary responding less, and that cannot be reversed. What does count then is what you do with the years after: strength training, calcium and vitamin D for bone, and the ordinary lifestyle for your vessels. With a wish for children and a high FSH, time is the factor that counts, and that belongs in a conversation with a doctor. Read FSH beside LH, which comes from the same gland and usually sits in the same draw, beside oestradiol, which is the ovaries' answer, and in women beside the cycle day. At the start of the cycle, day 2 to 5, the value is easiest to compare.
What lowers it
In the second half of the cycle the rhythm itself, on the pill the intention, and beyond those the signal from the brain.
| Cause | How often |
|---|---|
| Drawn in the second half of the cycleAfter ovulation oestradiol and progesterone keep the pituitary quiet; the luteal phase is the lowest of the cycle | Often |
| Hormonal contraceptionThe pill and most other hormonal contraception suppress FSH and LH; the low number is then the intention | Often |
| Eating too little, training too much or lasting stressWith an energy deficit the brain turns the signal down low; FSH, LH and oestradiol drop together and the cycle switches off | Sometimes |
| Anabolic steroidsTestosterone from outside shuts the pituitary down; FSH and LH fall and sperm production of your own disappears | Rare |
What raises it
Ovaries responding less, and around ovulation the rhythm.
| Cause | How often |
|---|---|
| After menopauseThe ovaries no longer respond and the pituitary pulls permanently hard; the band after the menopause begins above the ceiling of every cycle phase | Often |
| The years before the menopauseThe store of follicles shrinks and the pituitary pulls harder; FSH then fluctuates from month to month, high in one cycle and normal in the next | Sometimes |
| Drawn around ovulationJust before ovulation FSH is temporarily higher than in the phases beside it; that is the rhythm, not a finding | Sometimes |
| Premature ovarian insufficiencyBefore the age of forty; FSH then stays permanently high with a low oestradiol, and bone needs attention early | Rare |
| Testes making fewer sperm cellsIn men, after an infection, after chemotherapy or from a congenital cause; the pituitary then asks harder | Rare |
How does a FSH blood test work?
- Referral
- Not needed. You can have FSH measured without going through your GP.
- Fasting
- Not needed.
- When to draw
- In women at the start of the cycle, day 2 to 5 after the first day of menstruation; note the day. In men the moment matters little.
- The draw
- One tube of blood from a vein in your arm.
- The result
- A single number in U/l, at some labs written as E/l, the same unit. In women with a range per cycle phase; pick the phase that applies to you.
- Measured together
- LH and oestradiol, in the same draw. FSH takes its meaning from that company.
- Where to draw
- You can draw at 250+ locations near you, no referral needed. See the locations
Frequently asked questions
What is FSH?
Follicle-stimulating hormone is the signal with which the pituitary, a gland beneath your brain, sets the ovaries to work: it lets follicles mature, and the maturing follicle makes oestradiol. As soon as that oestradiol rises, the pituitary releases less FSH, like a thermostat. In men FSH drives the production of sperm cells. It is nearly always determined together with LH.
What is a normal FSH level?
That depends on your cycle phase. Where the labs overlap: at the start of the cycle 3.8 to 8.1 U/l, around ovulation 4.7 to 16.7, in the second half 1.8 to 5.1, and after the menopause 26.7 to 113.6. In men 1.5 to 12.0 U/l. For anyone wanting to follow the ovaries, what counts most is the value at the start of the cycle, day 2 to 5, and how it develops over the years.
What does a raised FSH mean?
That the pituitary is pulling harder on the ovaries because they respond less. After the menopause that is permanent, in the years before it fluctuates from month to month, and with premature ovarian insufficiency it happens before the age of forty. Around ovulation FSH is temporarily higher, and that is the rhythm. A high FSH beside a low oestradiol points at the ovaries themselves. In men it means testes making fewer sperm cells.
What does a low FSH mean?
In the second half of the cycle low is the ordinary picture, and on the pill the intention. Beyond those, together with a low oestradiol and a cycle that stays away, it points at the signal from the brain. In young, sporty women that is almost always eating too little for what you burn, training a lot, fast weight loss or stress, and it recovers with food, rest and time. In men a low FSH with a low LH goes with anabolic steroids.
Can an FSH test show that I am in the menopause?
Not reliably. In the years before the menopause FSH fluctuates from cycle to cycle, high one month and normal the next, so one measurement says little, and on the pill it is suppressed. The menopause is diagnosed on age, symptoms and the absence of periods; a GP does not as a rule measure FSH for it. After the menopause FSH does stay permanently high, above the ceiling of every cycle phase.
My cycle has stopped and I exercise a lot; what does FSH say then?
FSH shows where it lies. If it is low or normal, together with a low oestradiol and a low LH, your brain is temporarily switching reproduction off to save energy: the pattern of eating too little, training too much, fast weight loss or stress. That feels like fitness but is a deficit, and bone pays for it. It reverses with more food, especially carbohydrates and fat, fewer training hours and more sleep, and that takes months. If FSH is high instead, it is the ovaries.
What does FSH say in men?
How hard the pituitary is driving the testes to make sperm cells. A high FSH means testes making fewer, after an infection, after chemotherapy or from a congenital cause, and that is a question with a wish for children. A low FSH together with a low LH goes with anabolic steroids, which shut the pituitary down; production of your own recovers after stopping, but that takes months.
On which day of my cycle do I have FSH drawn?
At the start, day 2 to 5 after the first day of your period. Then the value is easiest to compare, over the years and with the range. Note the day at the draw, and have LH and oestradiol taken in the same draw. In men the moment matters little.
Do I need to fast for an FSH test?
No. What counts is the day of your cycle, and whether you use contraception, because that suppresses FSH.
Which tests include FSH?
FSH is in the Hormones men test (€129, also as an add-on for €109).
Related biomarkers
Read on
Sources
- 1.Unilabs, test catalogue (Dutch): FSH. 2026. bepalingenklapper.nl
- 2.Star-shl, test catalogue (Dutch): FSH. 2026. star-shl.nl
- 3.Certe, test catalogue (Dutch): FSH. 2026. bepalingenwijzer.certe.nl
- 4.Clinical Diagnostics, lab guide (Dutch): FSH. 2026. clinicaldiagnostics.nl
- 5.LESA Laboratory diagnostics (Dutch primary-care laboratory agreement). 2026. richtlijnen.nhg.org
Educational information only, not medical advice. Consult a healthcare professional for clinical decisions.
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