Follicle Stimulating Hormone (FSH)

What is Follicle Stimulating Hormone?

Follicle Stimulating Hormone (FSH) is produced by the pituitary gland and plays a crucial role in reproductive function. In women, it stimulates egg development and estrogen production; in men, it promotes sperm production. FSH levels vary with menstrual cycle phases in premenopausal women.

Why is it Tested?

Doctors order FSH to evaluate fertility issues, irregular periods, or symptoms of menopause. It’s also used to assess pituitary function, investigate delayed or precocious puberty, and monitor response to fertility treatments.

Normal Ranges

Reference ranges vary by lab and menstrual cycle phase. General adult guidelines:

Men: 1.5–12.4 mIU/mL
Women (premenopausal, follicular phase): 3.5–12.5 mIU/mL
Women (ovulatory phase): 4.7–21.5 mIU/mL
Women (postmenopausal): 25.8–134.8 mIU/mL

Timing of collection is critical for accurate interpretation in women.

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 FSH

Low levels may indicate:

Pituitary dysfunction
Hypothalamic disorders
Stress or significant weight loss
Certain medications or anabolic steroids

High FSH

Elevated FSH levels may suggest:

Ovarian failure or menopause
Primary testicular failure
Turner syndrome
Certain chemotherapy or radiation effects

How to Track Over Time

FSH patterns reveal important reproductive trends. In women, tracking FSH alongside menstrual cycles helps predict menopause transition. Rising FSH levels over time may indicate declining ovarian reserve before other symptoms appear.

Follicle Stimulating Hormone