What is a testosterone blood test?

A blood test for testosterone measures how much of this sex hormone is in your body.

Testosterone is produced by both males and females, although males usually produce much greater amounts.

Testosterone plays a role in many parts of your body including:

• maturation of the male sex organs
• sperm production
• growth of facial and body hair
• deepening of the voice
• sex drive
• muscle development

During puberty, males start to make large amounts of testosterone. It is made mainly in the testes, but also in the adrenal glands.

Females make a small amount of testosterone in their ovaries, adrenal glands and other body tissues. Some of this breaks down to form a type of oestrogen called oestradiol.

When is a testosterone blood test used?

A testosterone blood test can identify several endocrine (hormonal) conditions. Your doctor might suggest a blood test for testosterone if:

• you are having problems getting pregnant — both males and females may be tested
• you are a male with problems getting an erection
• you are a male with a low sex drive
• you are a female but have male features, such as a lot of body hair or a deep voice
• puberty has come very early, or is very late

Some conditions can also affect the amount of testosterone in your blood. These include:

• diabetes
• mumps
• tumours of the testicles or ovaries
• metabolic syndrome
• obesity

High alcohol intake and some medicines are also associated with lower testosterone levels.

Genetic conditions that cause hypogonadism (small genitals) can cause low testosterone levels. These conditions include:

• Klinefelter syndrome
• Kalman syndrome
• Prader-Willi syndrome

Where can I get a testosterone blood test?

You usually need to go to a pathology collection centre with a referral from your doctor. Your doctor will recommend one near you.

Sometimes, your doctor will collect blood for testing in their clinic. Blood tests are also routinely done in hospitals.

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How do I prepare for a testosterone blood test?

You usually need to fast (avoid eating) before getting a testosterone blood test, because food and drink can affect your results. In this case you can only drink water. You should have the test in the morning.

You can usually continue to take your usual medicines, though it's best to check with your doctor or the pathology collection centre ahead of time.

If you are having other blood tests done at the same time, you may need to prepare. Check with your doctor or the pathology collection centre if there is anything you need to do before your blood test.

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What happens during a testosterone blood test?

A health professional will take a sample of blood from a vein in your arm. The blood will then be sent to a laboratory for testing.

What do my testosterone blood test results mean?

Many things can affect your testosterone blood test results, including:

• your sex
• your age
• your general health
• any health conditions

A result outside the normal range does not always mean you have a health problem. You will need to discuss your results with your doctor to understand what they mean and what comes next.

Resources and support

You can read healthdirect's Guide to blood testing to learn more about blood tests in general, with information on:

• what to consider before having the test
• what happens during a blood test
• the accuracy of your results
• the costs of your blood tests

Pathology Tests Explained also has lots of information on blood tests including testosterone tests.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

For more information about men's health visit the Healthy Male website.

You can read more about testosterone in females on the Australasian Menopause Society website.

Other languages

Hormones Australia provides resources on hormone conditions, available in a variety of community languages.

Looking for information for Aboriginal and/or Torres Strait Islander people?

Find an Aboriginal Community Controlled Health Organisation (ACCHO) in your area.