Follicle Stimulating Hormone (FSH)

What is FSH and why is it important?

FSH stimulates the ovaries in women to produce and mature eggs and supports the production of oestrogen. In men, FSH plays a role in sperm production by acting on the testes. Because of its central role in reproductive function, abnormal FSH levels can indicate issues with the ovaries, testes, or pituitary gland.

FSH levels tend to rise when the ovaries or testes are not responding adequately, as the body attempts to stimulate hormone production. For this reason, FSH is often interpreted alongside other hormones such as LH, oestradiol, testosterone, or prolactin.

Why might I need an FSH test?

An FSH test may be recommended if you are experiencing irregular or absent periods, difficulty conceiving, symptoms of menopause, or signs of early puberty or delayed sexual development.

In men, FSH testing may be used when investigating low sperm count, fertility concerns, or hormonal imbalance. It is also commonly requested as part of a broader hormonal assessment to help understand the underlying cause of reproductive or endocrine symptoms.

What do the results mean?

High FSH levels may indicate reduced ovarian or testicular function, which can be seen in menopause or certain fertility-related conditions. Low levels may suggest a pituitary or hypothalamic cause.

FSH results are always interpreted in the context of age, sex, menstrual cycle timing, symptoms, and other hormone results. Your healthcare professional will explain what your result means for you and whether any further testing is appropriate.

How is the test performed?

The FSH test is performed using a simple blood sample collected during a short appointment. The procedure is routine, and our clinical team will ensure you are comfortable throughout.

Do I need to prepare the test?

No special preparation or fasting is required for this test unless you have been advised otherwise. In women, your clinician may advise testing on a specific day of the menstrual cycle.

Why Choose Marylebone Diagnostic Centre?

Marylebone Diagnostic Centre provides professional hormone testing in a calm and supportive environment, with fast turnaround times and clear communication.

Our experienced clinical team supports you in understanding your hormone results, helping you make informed decisions about your reproductive and hormonal health.