Understanding LH: Normal vs Optimal Ranges

?What is LH?

LH (luteinising hormone) is produced by the pituitary gland. In women, a sharp LH surge triggers ovulation. In men, LH stimulates testosterone production in Leydig cells. LH is measured alongside FSH to evaluate pituitary and gonadal function.

!Why It Matters

An LH surge test (using urine sticks or blood LH) is used to identify the fertile window and predict ovulation. Elevated LH with elevated FSH indicates primary gonadal failure. Elevated LH with low FSH (LH:FSH ratio > 2) can indicate polycystic ovary syndrome (PCOS) in women. Low LH (with low testosterone in men) points to pituitary or hypothalamic dysfunction.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• PCOS: irregular periods, excess hair growth (elevated LH)
• Hypogonadism: infertility, low sex drive

How to Improve Your Levels

• 1Treatment depends on whether hypogonadism is primary (gonadal) or secondary (pituitary)

When to Test

Day 2–3 for cycle evaluation; mid-cycle around day 14 to detect LH surge for ovulation prediction.

Related Biomarkers