TRT with Free Testosterone Blood Test, from our experts to you.
Dr Sam Rodgers MBBS, MRCGPChief Medical Officer

Who is a TRT with free testosterone test for?
Our TRT with Free Testosterone Blood Test profile is for men taking testosterone replacement therapy (TRT) who want to monitor their male and female hormones. Monitoring your hormone levels allows you and your practitioner to optimise your dose of testosterone replacement. This test is also useful if you are experiencing symptoms of low testosterone yet your total testosterone level is normal, and you want to measure your free testosterone as the next step.
What can I learn from a TRT with free testosterone test?
Our test includes total testosterone and a calculation of the amount of free or unbound testosterone that is available to your tissues. Most testosterone in your body is bound to proteins (sex hormone-binding globulin and albumin) and is unavailable to your cells. By measuring your total testosterone and your levels of SHBG and albumin, the laboratory can calculate your free testosterone level. If you have high levels of SHBG, your free testosterone will be lower, even when your total testosterone is normal.
Why check free testosterone and female hormones?
Low free testosterone can cause low libido, lack of muscle mass, and low mood. It is also important to check the levels of female hormones in your blood if you are taking TRT. High testosterone levels can also cause high oestradiol, especially if you are experiencing symptoms associated with high oestradiol (including the growth of breast tissue and low libido).
What's Included?
How to prepare for your test
Special Instructions
Prepare for your TRT with Free Testosterone 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. 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. If you are a woman take this test two to five days after the start of your period, ideally on day three. It can be taken any time if you do not have periods.