Follicle Stimulating Hormone Test

What is Follicle Stimulating Hormone?

Follicle-stimulating hormone (FSH) is a hormone (a chemical messenger) that occurs naturally in the body. FSH is important for fertility and reproduction, as well as for the sexual maturity and development of children. This hormone is produced by the pituitary gland at the base of the brain and released into the blood stream where it travels to a woman's ovaries and a man's testicles (testes).

During a woman's menstrual cycle, the release of FSH triggers the growth of ovarian follicles within the ovary. The follicles produce another hormone called oestrogen. The rise in oestrogen levels in the blood feeds back to the pituitary gland, which then reduces its release of FSH. With less FSH, only one follicle survives; this follicle increases its oestrogen production as it grows. This leads to the pituitary gland releasing more FSH and another hormone called luteinising hormone (LH), which results in an egg being released from a follicle, a process known as ovulation.

In the testicles of men, specialised cells called Sertoli cells are located in the lining of the tubules producing sperm. FSH stimulates the Sertoli cells to produce sperm in a process known as spermatogenesis.

Can I get this FSH test online?

The Online Clinic offers a self-collect blood kit, with your sample processed in a certified laboratory. Results are next day, with an interpretation from a doctor.

What is the FSH test?

The FSH test measures the amount of FSH in the blood or urine. You may also have checks on levels of other hormones, particularly LH, since FSH acts alongside LH to control reproductive functioning.

Why is a the FSH test important?

Both too much and too little FSH indicate that there is a problem with the functioning of the ovaries or testes or, rarely, in the pituitary gland.

In women, a FSH level that is too high causes over-stimulation of the ovaries, leading to the development of disturbances in the menstrual cycle, thickening of the womb lining, and development of ovarian cysts. It also causes symptoms, such as hot flashes, vaginal dryness, mood changes, sleep disturbance, and weight gain. High FSH levels can be caused by a pituitary gland disorder, such as ovarian hyperstimulation syndrome with symptoms including enlarged ovaries and abdominal pain. A FSH level that is too low results in poor ovarian function, prevents ovarian follicle development and ovulation, causing infertility.

In men, FSH levels need to be sufficient for complete development of sperm. When FSH levels are low, sperm production is also limited, although it may still be possible to father a child. However, in the total absence of FSH, there will be no sperm production and therefore infertility. Low FSH levels in men may also cause a low sex drive (libido), erectile dysfunction, low energy levels, and loss of muscle mass.

In children, puberty will be either early or delayed in cases of too much and too little FSH, respectively.

Who should have their FSH level tested?

Women may need a FSH test to help determine why they have irregular menstrual periods or why they have stopped, or whether they are in the perimenopause or in the menopause. The test is important when there is a need to find out if the ovaries are working properly, the cause of being unable to get pregnant and infertility, and the possibility of ovarian cysts or polycystic ovary syndrome.

Men have a FSH test usually to find the cause of their low sex drive or low sperm count, and to check if their testes are functioning normally. The FSH test is can be useful in determining whether a man is in the andropause (male menopause), why their partner is unable to get pregnant, and if they are infertile.

FSH testing may be required in men and women with a suspected pituitary disorder, as this affects how much FSH is produced in the body. FSH testing can also be useful in assessing damage to the ovaries and testes by chemotherapy, radiation, and poor lifestyle choices such as excess alcohol consumption.

How to test for FSH?

In women, blood FSH levels will vary during the menstrual cycle but normally don't alter very much in men. Advice is provided on when to collect a blood sample.

Only a small blood sample is needed for the FSH test, which you can easily collect yourself using a test kit from your doctor. Complete instructions on how to collect the blood sample are provided with the test kit. Briefly, once you have cleaned the tip of your little finger tip, prick the cleaned skin with the lancet. When blood drops appear, collect them in the collection tube until the blood level reaches the top line marked on the tube. If blood drops stop forming and the full blood sample has not been collected, then similarly use the other little finger tip as well. Place the cap on the collection tube and gently turn it upside down 5 to 10 times. Fill in the tube label, stick the label onto the collection tube, and put it in the packing wallet for posting. The FSH test results will be sent to your doctor who will explain what they show, and whether you need to have more tests.

What are normal FSH test results?

Your FSH level will depend on your age, biological sex, the laboratory used and, for women, the phase you are at in your menstrual cycle, if you are pregnant, or if you are in the menopause. You must inform your doctor what medicines you currently take, because some medicines increase FSH levels (e.g., clomiphene, cimetidine, levodopa, and digitalis), while others can lower FSH levels (e.g., contraceptives and hormone replacement therapies).

While FSH reference ranges vary across different laboratories, the following gives a guideline of normal FSH levels in females and males.

For females, normal FSH levels are:

• Before puberty: 0 to 4 IU/L
• During puberty: 0.3 to 10 IU/L
• During the years of menstruation: 4.7 to 21.5 IU/L
  • During the different phases of the menstrual cycle:
    • Follicular phase of the cycle: 1 to 9 IU/L
    • Midcycle: 6 to 26 IU/L
    • Luteal phase of the cycle: 1 to 9 IU/L
• During pregnancy: 0.1 IU/L from 26 to 30 days after ovulation
• After menopause 25.8 to 134.8 IU/L (menopause is likely in women with an FSH level of 30 IU/L plus one-year absence of menstrual periods).

For males, normal FSH levels are:

• Before puberty: 0 to 5 IU/L
• During puberty: 0.3 to 10 IU/L
• Adulthood: 1.5 to 12.4 IU/L

How to maintain normal FSH levels

Fertility in general can be maximised by good lifestyle choices such as a healthy diet, healthy body weight and regular exercise, while limiting caffeine and alcohol consumption, and avoiding sexually transmitted diseases, smoking, stress, over-exercising, lack of sleep, overheating the testicles (men), recreational drugs, environmental pollutants, and industrial chemicals.