What is follicle stimulating hormone?

Follicle stimulating hormone (FSH) is a hormone in the human body. It is made by your pituitary gland, which is in your brain.

What is the role of follicle stimulating hormone?

FSH is an important hormone for the reproductive system in both males and females. It plays a role in sexual development and functioning.

What does FSH do in females?

In females, FSH and another hormone called luteinising hormone (LH) help control the menstrual cycle (periods).

FSH helps with ovulation — when an egg is released each month by the ovaries.

The amount of FSH varies throughout the menstrual cycle. It is at the highest level just before ovulation.

What does FSH do in males?

In males, FSH signals the testes to make sperm.

The amount of FSH in males normally stays the same after puberty.

How is follicle stimulating hormone measured?

A blood test can measure your level of FSH.

Many hormones work together in the body. It is usual for other hormone tests to be done at the same time as the FSH blood test.

When may an FSH blood test be needed?

Your doctor may ask for an FSH blood test to be done:

• if you are having trouble getting pregnant
• to investigate irregular periods
• to help confirm menopause (usually only if early menopause is suspected)
• if you have a low sperm count
• if you start puberty earlier or later than usual

Why is the level of follicle stimulating hormone important?

In females, the FSH level can show if there is a problem with the ovaries or ovulation.

In males, a high level of FSH could mean there is an injury or problem with the testicles.

The levels of FSH can also show if your pituitary gland is not working properly.