Luteinizing Hormone (LH)

What is Luteinizing Hormone?

Luteinizing hormone (LH) is produced by the pituitary gland and plays a crucial role in reproductive function. In women, LH triggers ovulation and supports corpus luteum function. In men, LH stimulates testosterone production by the testes.

Why is it Tested?

Doctors order LH to investigate fertility issues, evaluate menstrual irregularities, diagnose PCOS, assess menopause status, investigate delayed or precocious puberty, and evaluate pituitary function. It’s often tested alongside FSH for comprehensive reproductive hormone assessment.

Normal Ranges

Reference ranges vary by gender and menstrual phase:

Men: 1.7–8.6 mIU/mL
Premenopausal women (follicular): 2.4–12.6 mIU/mL
Premenopausal women (mid-cycle): 14–96 mIU/mL
Postmenopausal women: 7.7–58.5 mIU/mL

In women, LH surges dramatically at ovulation, making timing of testing crucial.

Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Low LH

Reduced levels may indicate:

Pituitary dysfunction
Hypothalamic disorders
Stress or illness
Certain medications
Anorexia or excessive exercise

High LH

Elevated levels suggest:

Primary gonadal failure
Menopause
PCOS (in women)
Klinefelter syndrome (in men)
Pituitary adenoma

How to Track Over Time

LH levels fluctuate naturally in premenopausal women throughout their cycle. For fertility assessment, tracking LH surges helps predict ovulation. In menopause transition, rising LH levels indicate declining ovarian function. Regular monitoring helps assess reproductive health and hormone therapy effectiveness.

Luteinizing Hormone