Testosterone and Cortisol Blood Test, from our experts to you.
Dr Sam Rodgers MBBS, MRCGPChief Medical Officer
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What is the testosterone to cortisol (T:C) ratio?
The testosterone to cortisol (T:C) ratio is a marker that shows promise in assessing whether athletes are recovering well after intense training, and raised cortisol can inhibit the production of testosterone. T:C ratio is more sensitive to the stresses of training than either measure alone. Over time, you can trend your results to see how well you are recovering.
What does testosterone do?
Testosterone is a hormone that causes male characteristics. For men, it regulates the sex drive and controls bone mass, fat distribution, muscle mass, strength, and the production of red blood cells and sperm. Heavy alcohol use, liver disease, and using steroids can cause a decrease in testosterone levels. Women taking oestrogen therapy, however, may have increased testosterone levels.
What does cortisol do?
Cortisol is a steroid hormone, produced by the adrenal gland. It's vital for survival as it's involved in various functions such as immunity, regulating blood pressure, and releasing insulin for blood sugar maintenance. Cortisol is known as the stress hormone because it's secreted at higher levels during the body's fight or flight response to stress and is responsible for several stress-related changes in the body.
What's Included?
How to prepare for your test?
Special Instructions
Prepare for your Testosterone and Cortisol Blood Test by following these instructions. Please take your sample before 10am. Hormonal contraception can affect this test, taking a break from this and using barrier contraception will give more accurate results. Corticosteroid medication can affect this test, ask your doctor whether to stop before testing. If you use hormone gels, pessaries, patches, or tablets, we strongly recommend selecting a venous sample to minimise contamination sometimes seen with finger-prick tests. Otherwise, administer any hormone supplements using gloves, and make sure your fingers have not been in contact with hormone supplements for at least four weeks before taking the test. Hormones can be absorbed deep within the skin even after minimal contact and remain there for weeks despite vigorous handwashing. Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed.