Follicle Stimulating Hormone (FSH)

The Follicle Stimulating Hormone (FSH) test measures the level of FSH in the blood. FSH is a hormone produced by the pituitary gland that plays a vital role in reproductive health. In women, it stimulates the growth of ovarian follicles; in men, it supports sperm production. FSH testing is commonly used to evaluate fertility, menstrual irregularities, and the function of the reproductive organs.

1. What Is FSH?

• FSH is one of the key hormones involved in regulating the reproductive system.

• In women, it promotes the development of eggs in the ovaries and regulates the menstrual cycle.

• In men, it stimulates the testes to produce sperm.

• FSH levels fluctuate throughout a woman’s menstrual cycle and vary with age and hormonal status.

2. Why Is the FSH Test Performed?

This test is used to:

• Evaluate fertility issues in both men and women.

• Diagnose conditions such as polycystic ovary syndrome (PCOS), ovarian failure, or pituitary disorders.

• Determine the cause of irregular or absent periods (amenorrhea).

• Monitor the onset of menopause or perimenopause.

• Investigate early or delayed puberty in children.

3. FSH Reference Ranges

• Women (follicular phase): 4.7 – 21.5 mIU/mL

• Women (mid-cycle peak): 5.8 – 21.0 mIU/mL

• Women (luteal phase): 1.2 – 9.0 mIU/mL

• Postmenopausal women: 25.8 – 134.8 mIU/mL

• Men: 1.5 – 12.4 mIU/mL

• Ranges can vary depending on age, sex, and laboratory standards.

4. How to Interpret FSH Results

🔹 Elevated FSH:

• In women, may indicate primary ovarian failure, menopause, or PCOS.

• In men, may suggest testicular failure or damage.

🔹 Low FSH:

• May point to pituitary or hypothalamic dysfunction, such as hypopituitarism.

• Can also be due to stress, malnutrition, or extreme weight loss.

5. What Can Affect FSH Levels?

• Menstrual cycle phase or menopausal status

• Use of hormonal contraceptives or hormone replacement therapy

• Pituitary gland disorders

• Certain medications (e.g., clomiphene, cimetidine, levodopa)

• Health conditions like anorexia or extreme exercise

6. How Is the Test Performed?

• A blood sample is drawn from a vein, usually without fasting.

• In women, timing the test according to the menstrual cycle phase may be necessary.

7. When to See a Doctor

🚨 Contact your healthcare provider if you:

• Have difficulty conceiving or irregular menstrual cycles.

• Show symptoms of hormonal imbalance such as hot flashes, mood changes, or abnormal hair growth.

• Are experiencing early or delayed puberty.

🔹 Key Takeaways

✅ FSH is essential for reproductive health and fertility in both sexes.

✅ Abnormal FSH levels may indicate ovarian/testicular dysfunction or pituitary issues.

✅ FSH testing helps diagnose and monitor fertility concerns and hormone-related disorders.