What is LH? Luteinizing hormone, ovulation and blood levels
LH stands for luteinizing hormone. It is the hormone that triggers ovulation. Two different things get called an “LH test”: a blood test that measures LH, and the urine strips that predict ovulation. This page covers both.
LH
A single blood test for LH, the hormone that rises before ovulation. FSH is not included.
$49
See this test at HealthLabsPrice checked October 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.
What LH does
MedlinePlus says LH is made by the pituitary gland, a small gland at the base of the brain. In women who have periods, LH helps control the menstrual cycle and triggers the release of an egg from the ovary. LH levels quickly rise just before ovulation.
In men, LH causes the testicles to make testosterone. In girls at puberty, LH helps signal the ovaries to make estrogen.
If you want the ovulation test
The strips sold in pharmacies to predict ovulation are LH tests too. The FDA’s consumer page says the kits measure LH in urine to detect the LH surge that happens about 1 to 1.5 days before ovulation. It also says:
- It is a qualitative test: you find out whether LH is elevated, not whether you will definitely become pregnant.
- The kits detect LH reliably about 9 times out of 10, but only if you follow the instructions carefully.
- You need to start testing at the proper time in your cycle, or the test will be unreliable and you may miss the surge.
- Don’t use the test to prevent pregnancy, because it is not reliable for that.
Follow the instructions that come with the kit. The rest of this page is about the blood test.
When doctors test LH in blood
MedlinePlus says LH testing may be used to help find the cause of infertility, to check for conditions that affect the ovaries, to find the reason for irregular or stopped periods, and to help find out if menopause or perimenopause may have begun. It is usually done with an FSH test. See the LH and FSH test page.
At 45 or older, MedlinePlus says testing usually isn’t needed, because high levels of LH and FSH are usually a sign of normal perimenopause and menopause.
If you have periods, you may need to be tested at a specific point in your cycle. MedlinePlus also says to tell your provider about everything you take.
LH reference ranges
The ranges below are from the Oregon Health & Science University (OHSU) laboratory listing for LH, in mIU/mL, copied as published.
| Adult female | Reference range (mIU/mL) |
|---|---|
| Follicular | 2.1 to 10.9 |
| Midcycle | 19.2 to 103.0 |
| Luteal | 1.2 to 12.9 |
| Postmenopausal | 10.9 to 58.6 |
Source: Luteinizing Hormone, OHSU. The listing gives no further notes on these ranges. It also lists an adult male range, not shown here.
People search for “normal LH levels”. The source calls these reference ranges, and labs differ, so use the range printed on your own report. The midcycle row sits far above the others, which fits MedlinePlus’s note that LH rises quickly just before ovulation.
What high or low LH can mean
MedlinePlus says LH levels change through the month in women who have periods. An increase in LH a couple of weeks after your period usually means you’re ovulating normally. High LH through the month may mean the ovaries aren’t working properly. In women of childbearing age, higher than normal LH may mean a disorder that affects the ovaries, such as primary ovarian insufficiency or PCOS. At 45 or older, high LH may mean approaching menopause.
Lower than normal LH in adults is often a sign of a problem with the pituitary gland or hypothalamus. In women, low LH and FSH with missed periods may also be linked to extreme exercise, malnutrition, stress, or being very underweight.
Getting an LH blood test
The cheapest LH option is the LH-only blood test. The seller’s page says it measures LH only, with no FSH, estrogen, progesterone or testosterone, and that results appear in an online account within one to three business days. It says fasting isn’t required. It gives no cycle-day instruction, so follow your clinician’s order.
If FSH is part of your question, FSH and LH on one order is the better fit. LH is usually read next to FSH.
Sold by HealthLabs. Prices checked October 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.
MedlinePlus says at-home urine tests are the ones usually used to track ovulation. The blood test is mostly for the other uses listed above. The cycle timing tool covers when cycle-day testing is usually done.
What a result can’t tell you
An LH number doesn’t diagnose a condition by itself. A clinician reads it with your age, symptoms and FSH. See one if your periods are irregular or have stopped, or if you might be pregnant.
LH
$49
See this test at HealthLabsPrice checked October 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.
Keep reading
- What is FSH? Follicle-stimulating hormone explained
FSH is a pituitary hormone that helps control the menstrual cycle and egg growth. Learn what it does, why it rises at menopause and when it is tested.
- LH and FSH test: why they're tested together and what the ratio means
LH and FSH are usually tested together. See why, when the LH:FSH ratio is used in PCOS questions, how cycle day matters, and one lab's published ranges.
- FSH test: what it measures, why it's ordered and how to prepare
An FSH test measures follicle-stimulating hormone in blood. See why it is ordered, how cycle timing matters, what results can mean and what it can't tell you.
- FSH levels: published reference ranges by cycle phase
FSH reference ranges by cycle phase and after menopause from one named hospital lab, plus what high and low FSH can mean and why your lab's range is the one to use.