LH blood test
Luteinizing hormone
In short
A typical adult LH result is 1.9 to 14.6 mIU/mL for women (follicular phase (first half)), 12.2 to 118 mIU/mL for women (mid-cycle peak), 0.7 to 12.9 mIU/mL for women (luteal phase (second half)), 5.3 to 65.4 mIU/mL for women (after menopause) and 1.3 to 9.6 mIU/mL for men. A high LH is expected at mid-cycle and after menopause. Otherwise, it can be a sign the ovaries or testicles are not keeping up, so the brain pushes harder. Always read your result against the range printed on your own report.
A brain hormone that triggers ovulation and drives testosterone in men.
LH (luteinizing hormone) comes from the pituitary, a small gland at the base of the brain. In women it surges mid-cycle to release an egg; in men it tells the testicles to make testosterone. In women, a result only makes sense next to the day of the cycle, or menopause status.
Is my LH high or low?
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Typical range
| For | Range | Unit |
|---|---|---|
| Female · follicular phase (first half) | 1.9–14.6 | mIU/mL |
| Female · mid-cycle peak | 12.2–118 | mIU/mL |
| Female · luteal phase (second half) | 0.7–12.9 | mIU/mL |
| Female · after menopause | 5.3–65.4 | mIU/mL |
| Male | 1.3–9.6 | mIU/mL |
Typical ranges for adults. Labs differ a little, so the range printed next to your result is the one to go by.
If your LH is high
A high LH is expected at mid-cycle and after menopause. Otherwise, it can be a sign the ovaries or testicles are not keeping up, so the brain pushes harder.
Common reasons
- The mid-cycle surge, just before ovulation
- Menopause, or the years leading up to it
- PCOS (polycystic ovary syndrome), a common hormone condition, in women
- Past chemotherapy or radiation treatment
- Less often: the ovaries or testicles slowing early, from genes, injury or infection
If your LH is low
A low LH is common with birth control pills and hormone treatment, and with very low weight or hard training. Less often, it can be a sign of a problem in the pituitary gland.
Common reasons
- Birth control pills or other hormone treatment
- Male hormone treatment or muscle-building steroids
- Stress, very low weight, eating too little or very hard training
- High prolactin, another pituitary hormone, which can quiet LH
- Less often: a problem in the pituitary gland or the hypothalamus (brain control center)
What can throw it off
The day of the cycle and hormone treatments change LH a lot, and biotin, a hair-and-nail supplement, can distort some tests.
Questions to take to your appointment
- 1Does this result fit the day of my cycle when it was drawn?
- 2What do my FSH and estradiol show alongside it?
- 3Could my birth control or other hormones explain it?
Read together with
Doctors rarely read LH alone. These usually sit next to it.
Quick answers
What is the LH blood test?
LH (Luteinizing hormone): A brain hormone that triggers ovulation and drives testosterone in men. LH (luteinizing hormone) comes from the pituitary, a small gland at the base of the brain. In women it surges mid-cycle to release an egg; in men it tells the testicles to make testosterone. In women, a result only makes sense next to the day of the cycle, or menopause status.
What is a normal LH level?
For most adults, LH is typically 1.9 to 14.6 mIU/mL for women (follicular phase (first half)), 12.2 to 118 mIU/mL for women (mid-cycle peak), 0.7 to 12.9 mIU/mL for women (luteal phase (second half)), 5.3 to 65.4 mIU/mL for women (after menopause) and 1.3 to 9.6 mIU/mL for men. Labs differ a little, so the range printed next to your result is the one to go by.
What does a high LH mean?
A high LH is expected at mid-cycle and after menopause. Otherwise, it can be a sign the ovaries or testicles are not keeping up, so the brain pushes harder. Common reasons include the mid-cycle surge, just before ovulation; menopause, or the years leading up to it; PCOS (polycystic ovary syndrome), a common hormone condition, in women; and past chemotherapy or radiation treatment. A doctor reads it together with your other results and how you feel.
What does a low LH mean?
A low LH is common with birth control pills and hormone treatment, and with very low weight or hard training. Less often, it can be a sign of a problem in the pituitary gland. Common reasons include birth control pills or other hormone treatment; male hormone treatment or muscle-building steroids; stress, very low weight, eating too little or very hard training; and high prolactin, another pituitary hormone, which can quiet LH.
What can affect my LH result?
The day of the cycle and hormone treatments change LH a lot, and biotin, a hair-and-nail supplement, can distort some tests.
What should I ask my doctor about my LH?
Questions worth taking to the appointment: Does this result fit the day of my cycle when it was drawn? What do my FSH and estradiol show alongside it? Could my birth control or other hormones explain it?
What this page can’t do
It reads each number on its own.
Doctors read results together — ALT with AST, ferritin with hemoglobin, TSH with free T4. A pattern says more than any single flag.
It doesn't know you.
Your age, your medicines, how you feel and your last result all change what a number means.
It doesn't remember.
Close this page and your results are gone. That's on purpose: nothing was ever sent to us.
We also make Vita: Health Coach, an app for those parts. It reads your whole report with your medicines and history in mind, answers follow-up questions in plain words, and keeps your reports in one place — for you and for the people you look after.
Vita: Health Coach on the App StoreSources
- Mayo Clinic Laboratories — Luteinizing hormone (LH), serum
- MedlinePlus — Luteinizing hormone (LH) levels test
Stuck on a word? See the medical words. How we choose our sources. More about Vita Health Coach.