Follicle Stimulating Hormone (FSH)Levels: What You Should Know

Follicle-stimulating hormone (FSH) is important for reproduction. FSH regulates the menstrual cycle and stimulates egg growth in the ovaries. For men, FSH helps make sperm.

However, too little or too much FSH can cause infertility (inability to become pregnant). Knowing your FSH levels can help you understand your reproductive health.

This article will explain FSH levels and how it affects fertility for women and men.

What Is Follicle Stimulating Hormone (FSH)?

Follicles are small sacs of fluid found inside a woman's ovaries. They influence the menstrual cycle by secreting hormones. Each follicle has the potential of releasing an egg for fertilization. FSH is a hormone produced by a small gland in your brain called the anterior pituitary gland. FSH levels in both women and men are directly linked to fertility.

FSH Levels and Fertility

In women, FSH increases the body's production of estradiol, a type of estrogen that helps eggs mature and release from the follicle. At the end of your period, estrogen levels are low, signaling the pituitary gland to send more FSH to stimulate eggs in the ovary to grow. This process helps follicles mature and release the egg. Although there could be many follicles; usually only one releases an egg at ovulation. Your body reabsorbs the unused follicles.

In addition to increasing testosterone levels, FSH stimulates testicular growth in men and makes a protein responsible for creating and maintaining normal sperm cells.

What Is an FSH Level Test

A blood test can measure the level of FSH in your body. Luteinizing hormone (LH) works closely with FSH to regulate menstruation, generate the release of an egg from the ovary, produce estrogen in women and testosterone in men. Therefore, FSH and LH levels are drawn in both women and men to help understand their reproductive health.

Purpose of FSH Level Test in Women

Approximately 6% of American women between the ages of 15 and 44 cannot get pregnant after one year of trying. FSH levels can help identify fertility issues or hormonal imbalances. The following are reasons why a woman may need an FSH level drawn:

• Not achieving pregnancy after 12 months of trying
• Irregular periods
• Determine if she is perimenopausal or has gone through menopause
  

FSH Level Test Results in Women

For women who are still menstruating, an FSH level will likely be drawn on the third day of the menstrual cycle, day one being the first day of menstruation. FSH levels vary by age, puberty status, and gender. Here are the normal FSH ranges based on puberty status:

• Before puberty: 0 to 4.0 milli-international units per milliliter (mIU/mL) (0 to 4.0 international units per liter ( IU/L))
• During puberty: 0.3 to 10.0 milli-international units per milliliter (0.3 to 10.0 international units per liter)
• Women who are still menstruating: 4.7 to 21.5 milli-international units per milliliter (4.5 to 21.5 international units per liter)
• After menopause: 25.8 to 134.8 milli-international units per milliliter (25.8 to 134.8 international units per liter)

High FSH Levels in Women

High FSH levels can mean your body is working harder to produce the hormone, and you're not producing quality eggs. Some conditions can cause elevated FSH levels, including:

• Menopause
• Polycystic ovary syndrome (PCOS)
• Primary ovarian insufficiency (POI)
• Pituitary gland tumor
• Chromosomal abnormalities like Turner's syndrome
• Thyroid disorders
• Alcohol abuse

Hot flashes, irregular periods, skin and hair changes, poor sleep, and the inability to become pregnant are associated with high FSH levels.

Low FSH Levels in Women

Having a low FSH level can indicate:

• You aren’t making eggs
• The pituitary gland is not functioning correctly
• There is a problem with the hypothalamus (controls the pituitary gland)
• You are underweight or have lost weight quickly
• Eating large amounts of soy
• You may have hypothyroidism

Symptoms of low FSH levels include delayed puberty, infertility, and irregular menstrual cycles.

Purpose of FSH Level Test in Men

Fertility is never just a woman's issue; men can also contribute to infertility. Around 8% of American couples struggle with infertility due to the male. The following are reasons why men may need an FSH level drawn:

• Partner has not achieved pregnancy after 12 months of trying
• Decreased sex drive
• Experiencing: fatigue, weakness, weight loss, or decreased appetite
  

FSH Level Test Results in Men

Here is the normal FSH level range in men:

• Before puberty: 0 to 5.0 milli-international units per milliliter (0 to 5.0 international units per liter )
• During puberty: 0.3 to 10.0 milli-international units per milliliter (0.3 to 10.0 international units per liter)
• Adult: 1.5 to 12.4 milli-international units per milliliter (1.5 to 12.4 international units per liter)
  

High FSH Levels in Men

Factors that lead to elevated FSH levels in men include:

• Increasing age
• Damaged testicles (from chemotherapy, radiation, or alcohol abuse)
• Genetic conditions like Klinefelter syndrome
• Pituitary gland tumor
• Hormone treatment

Symptoms associated with increased FSH levels in men are loss of libido, tiredness, decreased sperm count, and moodiness.

Low FSH Levels in Men

Similarly, men with low FSH levels can have pituitary gland or hypothalamus insufficiencies. In addition, low levels of FSH can inhibit the growth of the testicles and cause a low sperm count. Men with a low FSH level can experience erectile dysfunction.

Medications Can Affect FSH Levels

Certain medications can affect FSH levels. Medications that can increase FSH levels include:

• Ginseng
• Aldactone (spironolactone)
• Tagamet (cimetidine)

Medications that can lower FSH levels include:

• Estrogen
• Testosterone
• Steroids
• Oral contraceptives

Summary

FSH plays an important role in the reproductive health of both women and men. Too much or too little of the hormone can affect your fertility. A blood test can be done to evaluate your FSH level. Normal FSH levels depend on age, puberty status, and gender. Sometimes medications and lifestyle changes can affect your FSH level.

A Word From Verywell

If you and your partner have been trying to conceive for at least a year with no success, then it may be time to see your healthcare provider. There can be some hesitancy about seeking help, fearful of a medical problem. However, you are not alone. Having hormone levels checked is a nearly painless and easy way to understand both you and your partner's reproductive health.