What is LH?
LH, luteinising hormone, comes from the same gland as FSH, the pituitary, and acts on the same organs. Where FSH lets the follicles mature, LH gives the starting signal: once the maturing follicle makes enough oestradiol, the pituitary releases a large amount of LH in one go, and about a day later the egg is released. That surge lasts a day or two, and it is that surge an ovulation test picks up in urine. Afterwards LH turns the empty follicle into the corpus luteum, which makes progesterone. In men LH is the hormone that sets the testes to making testosterone. Here too a thermostat is at work: if there is enough testosterone, the pituitary releases less LH; if there is too little, more. That is why, with a low testosterone, LH tells you where the problem sits: a high LH means testes that no longer deliver, a low LH means a brain that is not asking. Your report shows LH in U/l, in women with a range per cycle phase, of which the surge around ovulation sits a multiple higher than the rest, and in men with one range. Without a cycle day an LH value in women cannot be read: the same value is ordinary mid-surge and too high a week later.
Why is LH relevant?
LH is the hormone of the moment. For anyone who wants to become pregnant the LH surge is the window: ovulation follows within one to two days, and that is exactly what an ovulation test measures. For anyone who wants to understand the cycle, LH together with FSH shows whether the brain is driving the ovaries normally. Two patterns are worth knowing. In PCOS, LH often stands raised while FSH stays normal, and that skewed ratio goes with the missing ovulation, the higher androgens and the insulin resistance that characterise the syndrome; losing weight around the middle and less sugar and fast carbohydrates are the levers there. With eating too little, training a lot, fast weight loss or lasting stress the opposite happens: LH and FSH drop away together, ovulation stays away and oestradiol falls. Periods stop or become irregular, and in a sporty woman that is not fitness but a deficit. In men LH is the value that makes a low testosterone readable. Low testosterone with a low LH is almost always the signal from the brain: excess weight, sleep apnoea, long-term stress, some medicines, and anabolic steroids, which shut the pituitary down. Low testosterone with a high LH is testes making less, with age or after damage. The first can usually be reversed with lifestyle, the second cannot, and LH is the number that keeps the two apart. For diagnosing the menopause LH, like FSH, is less suitable than it seems: it fluctuates in the years before, and the menopause is diagnosed on symptoms and the absence of periods.
LH reference ranges
What counts beside the number:
- Your cycle day: mid-surge the same value is ordinary and a week later too high
- FSH, which comes from the same gland: in PCOS LH stands higher than FSH, with an energy deficit they drop together
- Oestradiol, and a week after ovulation progesterone, which shows whether ovulation actually happened
- Contraception, which suppresses the LH surge
- Your energy balance: food, training hours, weight loss and stress
- In men: testosterone beside it, and the time of day, because LH is most stable in the morning
The bands above are where the labs overlap; the range on your own report may be wider, especially around ovulation, and there is no national normal value. One lab publishes no range for LH, so the bands come from three tables. The menopause is not diagnosed on LH. Pick the phase that applies to you.
What Dutch labs actually use
Three labs publish a reference value for LH, and they do so not per age but per cycle phase. Star-shl publishes no reference value for LH, so this page sets three tables side by side instead of four. Around ovulation they diverge furthest. Unilabs lets that phase, which it calls Mid.cyclus, start at 7.6 U/l, Certe at 14 and Clinical Diagnostics only at 19.2: one lab's floor sits at more than double the other's, while their ceilings of 89.1, 95.6 and 103.0 sit close together. In the other phases they are nearer to each other. Where the three labs overlap, the follicular phase runs from 2.4 to 10.9 U/l, the luteal phase from 1.2 to 11.4 and the post-menopausal band from 10.9 to 58.5. For men 1.7 to 8.6 U/l is left.
2.4 – 10.9U/l
Between 1.8 and 2.4 and between 10.9 and 12.6 it differs per lab, because each lab sets its limits on its own method and population. Above 12.6 every lab calls it abnormal.
Every age, per lab
| Laboratory | Group | Reference range |
|---|---|---|
| Unilabs(Saltro, Medlon, SHO, Atalmedial)2026 | Follicular phase (from 14 yrs) | 1.8–11.8 U/l |
| Mid-cycle (from 14 yrs) | 7.6–89.1 U/l | |
| Luteal phase (from 14 yrs) | 0.6–14.0 U/l | |
| Post-menopausal (from 14 yrs) | 5.2–62.0 U/l | |
| Men from 20 yrs | 0.6–12.1 U/l | |
| Certe2026 | Men (pubertal and post-pubertal) | 1.7–8.6 U/l |
| Women follicular phase (day 1–12) | 2.4–12.6 U/l | |
| Women ovulation peak (day 13–15) | 14–95.6 U/l | |
| Women luteal phase (day 16–28) | 1–11.4 U/l | |
| Women post-menopausal | 7.7–58.5 U/l | |
| Clinical Diagnostics2026 | Men | 1.2–8.6 U/l |
| Women follicular phase | 2.1–10.9 U/l | |
| Women ovulation peak | 19.2–103.0 U/l | |
| Women luteal phase | 1.2–12.9 U/l | |
| Women post-menopausal | 10.9–58.6 U/l |
Each band as the lab publishes it, retrieved in 2026, unless marked otherwise.
LH high or low: what it means
A high LH in women is usually timing: the surge around ovulation, or the years after the menopause, in which LH like FSH stays permanently higher. Beyond those it is usually PCOS, with an LH higher than the FSH beside it. In men a high LH means testes making less testosterone, so that the pituitary asks harder. A low LH is the ordinary picture at the start and in the second half of the cycle, and on the pill the intention. Beyond those, together with a low FSH and oestradiol, it points at the signal from the brain: an energy deficit, overtraining, fast weight loss or stress, and rarely the pituitary itself. In men a low LH with a low testosterone is the signal from the brain, and excess weight, sleep apnoea, stress, opioids and anabolic steroids are the usual causes. Where LH is low from an energy deficit, the lever is the balance: more food, especially carbohydrates and fat, fewer training hours, more sleep, no crash diet; count on months. In PCOS losing weight around the middle and less sugar work, because insulin resistance sits beneath the skewed ratio. In men with a low LH, losing weight, sleep and stopping anabolic steroids work; after steroids the recovery of production of your own takes months to more than a year. A high LH from ovaries or testes that no longer respond cannot be reversed with lifestyle. LH belongs beside FSH, and in women beside the cycle day and oestradiol; progesterone a week later shows whether ovulation really happened. In men testosterone belongs beside it. And for questions about the signal from the brain, have blood drawn in the morning, because LH is released in pulses and is most stable in the morning.
What lowers it
At the start and in the second half of the cycle the rhythm, on the pill the intention, and beyond those the signal from the brain.
| Cause | How often |
|---|---|
| Drawn early in the cycleAt the start of the cycle LH is low and the pituitary is waiting for the signal from oestradiol; low is then the rhythm itself | Often |
| Drawn in the second half of the cycleAfter the surge LH falls back and oestradiol and progesterone keep the pituitary quiet | Often |
| Hormonal contraceptionThe pill and most other hormonal contraception suppress the LH surge, and with it ovulation; 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; LH, FSH and oestradiol drop together and the cycle switches off. In men testosterone then falls with it | Sometimes |
| Anabolic steroidsTestosterone from outside shuts the pituitary down; LH and FSH fall and production of your own testosterone and sperm cells disappears | Rare |
What raises it
The surge around ovulation, the years after the menopause, and beyond those PCOS or testes making less.
| Cause | How often |
|---|---|
| The peak around ovulationThe starting signal for ovulation, a multiple higher than the rest of the cycle and a day or two long; it is the surge an ovulation test picks up | Often |
| After menopauseThe ovaries no longer respond and the pituitary pulls permanently harder; LH then stands higher than in the cycle, like FSH | Often |
| Polycystic ovary syndrome (PCOS)LH stands higher than FSH, ovulation stays away and the androgens are higher; insulin resistance and belly fat sit beneath it | Sometimes |
| Testes making less testosteroneIn men: with age or after damage the testes deliver less, and the pituitary asks harder; a high LH with a low testosterone | Rare |
How does a LH blood test work?
- Referral
- Not needed. You can have LH measured without going through your GP.
- Fasting
- Not needed.
- When to draw
- For questions about how the cycle is driven at the start, day 2 to 5, together with FSH and oestradiol; note the day. Anyone wanting to catch ovulation itself does that at home with an ovulation test, because the surge only lasts a day or two. In men in the morning, together with testosterone.
- The draw
- One tube of blood from a vein in your arm.
- The result
- A single number in U/l, in women with a range per cycle phase; pick the phase that applies to you.
- Measured together
- FSH always, and for questions about the cycle oestradiol and progesterone; in men testosterone.
- Where to draw
- You can draw at 250+ locations near you, no referral needed. See the locations
Frequently asked questions
What is LH?
Luteinising hormone comes from the pituitary, a gland beneath your brain. In women a surge in LH gives the starting signal for ovulation, about a day before it, and afterwards turns the empty follicle into the corpus luteum that makes progesterone. In men LH sets the testes to making testosterone. It is nearly always determined together with FSH.
What is a normal LH level?
That depends on your cycle phase. Where the labs overlap: at the start of the cycle 2.4 to 10.9 U/l, around ovulation 19.2 to 89.1, in the second half 1.2 to 11.4, and after the menopause 10.9 to 58.5. In men 1.7 to 8.6 U/l. The range on your own report may be wider, certainly around ovulation.
What does a raised LH mean?
In women usually timing: the surge around ovulation, which lasts a day or two, or the years after the menopause. Beyond those it is often PCOS, in which LH stands higher than the FSH beside it, ovulation stays away and the androgens are higher; losing weight around the middle and less sugar are the levers there. In men a high LH means testes making less testosterone, so that the pituitary asks harder.
What does a low LH mean?
At the start and in the second half of the cycle low is the rhythm, and on the pill the intention. Beyond those, together with a low FSH and oestradiol and a missing cycle, your brain is turning the ovaries down low: eating too little, training too much, fast weight loss or stress. In men a low LH with a low testosterone is the signal from the brain, from excess weight, sleep apnoea, stress, opioids or anabolic steroids, and that can usually be reversed.
How does an ovulation test work, and what does it have to do with LH?
An ovulation test measures LH in urine. Just before ovulation the pituitary releases a lot of LH in one go, and that surge lasts a day or two; the test turns positive as soon as the surge begins, and ovulation follows within one to two days. A blood test rarely catches that surge at the right moment; for catching ovulation the home test is therefore more practical, and for whether ovulation really happened, progesterone a week later.
What does LH say in men?
Where a low testosterone comes from. A low testosterone with a low LH is the signal from the brain: excess weight, sleep apnoea, long-term stress, some medicines and anabolic steroids shut the pituitary down, and that can usually be reversed with losing weight, sleep and stopping the drugs. A low testosterone with a high LH is testes making less, with age or after damage. Have blood drawn in the morning, together with testosterone.
What does LH say in PCOS?
In PCOS LH often stands higher than FSH, while normally they sit in the same order. That skewed ratio goes with the missing ovulation and the higher androgens of the syndrome, and beneath it in most women sits insulin resistance. Losing weight around the middle and less sugar and fast carbohydrates often bring ovulation back. The diagnosis is not made on LH alone, but on the combination of cycle, androgens and ultrasound.
On which day of my cycle do I have LH drawn?
For questions about how the cycle is driven at the start of the cycle, day 2 to 5, together with FSH and oestradiol, and note the day. Anyone wanting to catch ovulation itself does that at home with an ovulation test, because the surge only lasts a day or two. In men in the morning.
Do I need to fast for an LH test?
No. What counts is the day of your cycle, whether you use contraception, and in men the time of day: LH is released in pulses and is most stable in the morning.
Which tests include LH?
LH is in the Hormones men test (€129, also as an add-on for €109).
Related biomarkers
Read on
Sources
- 1.Unilabs, test catalogue (Dutch): LH. 2026. bepalingenklapper.nl
- 2.Certe, test catalogue (Dutch): LH. 2026. bepalingenwijzer.certe.nl
- 3.Clinical Diagnostics, lab guide (Dutch): LH. 2026. clinicaldiagnostics.nl
- 4.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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