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Take-home points
- Testosterone blood tests usually take place in the morning.
- You will probably be advised to fast before your testosterone test.
- Repeat tests to verify testosterone readings are common.
- A healthcare professional should explain your testosterone results and, if needed, outline the various treatment options.
What is a testosterone blood test?
A testosterone levels test measures the amount of testosterone in a sample of your blood. A doctor might recommend a test to understand whether your symptoms can be explained by abnormal testosterone levels, or to assess whether any health conditions, medications, or lifestyle choices are affecting your testosterone production.
Here is what you should know before your testosterone blood test.
Will I need to do anything to prepare for the test?
A doctor or health provider should outline important details before your testosterone blood test, including how you can prepare.
Considering that nutrients from food can acutely change circulating testosterone levels, you will probably be advised to fast (not eat or drink) for several hours before the test.1,2,3 This practically means that people delay or skip their morning meal, as most testosterone tests occur in the morning. Consuming non-caloric drinks such as water is fine.
It is possible that you will be asked to stop taking certain medications that could affect your testosterone levels. These medications can include steroids, hormone therapies, beta-blockers, anticonvulsants, barbiturates, and opioids, among other examples. If you are unsure whether to temporarily stop taking a certain medication before your test, please ask your doctor.
If you fear medical procedures that involve needles, please communicate this to your doctor. Some anxiety-reducing techniques and behavioural therapies can help with certain types of phobias.
What happens during a testosterone blood test?
Testosterone tests are rather straightforward. A healthcare professional will take a blood sample from a vein in your arm using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a sting when the needle goes in but reports of pain are rare. The test should take no longer than five minutes.
Are there any risks with a testosterone blood test?
There is little risk to most blood tests, including a testosterone test. Remember, only a small amount of blood is withdrawn and analysed - nothing other than the needle (for a brief moment) is entering your body. You may note a slight pain or bruising after the needle is inserted but most symptoms quickly and naturally resolve.
When to take a testosterone blood test?
Due to natural fluctuations in your testosterone levels throughout the day, guidelines recommend collecting testosterones sample in the early morning: between 7am and 10am.4 Your testosterone levels tend to be more stable during these hours, and typically at their highest. Measuring testosterone at any other time of day may not accurately indicate endogenous (internal) testosterone production.
Fasted testosterone tests in the morning (approximately 8 am) are validated for assessing low testosterone and hypogonadism.
Do I need to take more than one testosterone blood test?
Although one test is better than none, a healthcare professional may recommend that you take two or three tests over weeks or months to confirm a testosterone reading or calculate an average reading. Testosterone levels vary and fluctuate over hours, days, and weeks. Approximately 30% of patients with an abnormal testosterone reading in the first test will have a ‘normal’ testosterone reading in a repeat test.5
What do the results mean?
A healthcare professional should discuss your testosterone test results with you. If not, we encourage you to prompt such a discussion – it is important to understand how your results relate to your symptoms, general health, and long-term disease risk.
You might be interested in our article that explains testosterone test results in more detail.
How can I treat my abnormal testosterone levels?
If you are diagnosed with abnormal testosterone levels, a healthcare professional should discuss various treatment options that can help. These options range from lifestyle, medical, and surgical interventions - all of which can be helpful depending on your specific case. Read our article on treating low testosterone levels and hypogonadism as a starting guide.
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References
- Caronia L, et al. Clin Endocrinol 2013;78(2):291–6.
- Lehtihet M, et al. Andrologia 2012;44(6):405–10.
- Volek JS et al. Metabolism. 2001;50(11):1351-5.
- Bhasin S et al. J Clin Endocrinol. 2010;95(6):2536-59.
- Rivas AM et al. Proc (Bayl Univ Med Cent). 2014;27(4): 321–324.
