Sex Hormones

LH (Luteinizing Hormone) — What Your Blood Test Result Means

ScanHealth Learn Sex Hormones LH (Luteinizing Hormone)

The Ovulation and Testosterone Trigger

LH is the signal your pituitary sends to your gonads. In women, the LH surge triggers ovulation (what ovulation kits detect). In men, LH continuously stimulates testes to produce testosterone. LH tells you whether a hormone problem is in the brain (pituitary) or the gonads.

What is LH (Luteinizing Hormone)?

LH is a gonadotropin from the anterior pituitary. Pulsatile secretion. In women: fluctuates dramatically (low → surge → moderate). In men: relatively stable. LH:FSH ratio >2 in women suggests PCOS.

What High LH (Luteinizing Hormone) Means

Pituitary sending a strong signal. Women: ovulation surge, menopause (pituitary screaming at non-responsive ovaries), or PCOS. Men: testes not responding (primary hypogonadism).

Common symptoms:

Women: hot flashes (menopause), irregular periods (PCOS) · Men: indicates testicular failure

What Low LH (Luteinizing Hormone) Means

Pituitary isn't sending enough signal. From stress, extreme weight loss, pituitary tumors, or anabolic steroid use.

Common symptoms:

Women: absent periods, infertility · Men: low testosterone symptoms · Both: low libido, fatigue

Why It Matters

When normal:

Triggers ovulation

Stimulates testosterone production

Distinguishes primary vs secondary hypogonadism

Guides fertility treatment

Risks if abnormal:

High LH + low sex hormones = gonadal failure

Low LH + low sex hormones = pituitary/hypothalamic problem

Elevated LH:FSH = PCOS pattern

What Can Cause Abnormal Levels?

Menopause/Gonadal Failure (high)

50% likely

No gonadal feedback → pituitary increases LH.

Hypothalamic/Pituitary Dysfunction (low)

40% likely

Stress, eating disorders, pituitary tumors suppress LH.

PCOS (high/elevated ratio)

Increased GnRH frequency preferentially raises LH over FSH.

Anabolic Steroids (low)

Exogenous testosterone suppresses LH via negative feedback.

Hyperprolactinemia (low)

High prolactin suppresses GnRH and LH.

What You Can Do

Adequate caloric intake and body fat

Impact: Undernutrition is a major LH suppressor \u00B7 Timeline: 4-12 weeks

Stress management

Impact: Cortisol suppresses GnRH and LH \u00B7 Timeline: 4-8 weeks

If lifestyle changes aren't enough:

Zinc and vitamin D optimization

Impact: Support reproductive hormone signaling \u00B7 Timeline: 4-8 weeks

Recommended retest: Women: day 3; Men: morning; 4-8 weeks after intervention

Related Markers

fsh testosterone_total estradiol progesterone prolactin shbg
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice. Always consult your doctor for diagnosis and treatment.

Got your blood test report?

Upload your PDF and understand ALL your markers in 2 minutes. Plain language. Traffic light status. No medical jargon.

Analyze My Report — Free

First report is free. No credit card needed.

Browse all markers