Free Testosterone (calculated), cFT
Available with home visit We remind you that independent interpretation of the results is unacceptable, the information provided below is for reference purposes only.
Calculated free testosterone represents the biologically active fraction of testosterone that can enter tissues and exert hormonal effects in the body. This parameter is calculated based on total testosterone and SHBG (sex hormone-binding globulin), the main protein responsible for testosterone transport in the bloodstream.
The assessment of calculated free testosterone provides a more accurate evaluation of androgen status than total testosterone measurement alone, particularly in situations where SHBG levels are altered. This test is useful for evaluating reproductive function and investigating hormonal imbalances in both men and women.
Indications
- evaluation of testosterone deficiency in men;
- decreased libido and erectile dysfunction;
- male infertility;
- reduced muscle mass and decreased bone density;
- chronic fatigue and reduced physical performance;
- diagnosis and monitoring of polycystic ovary syndrome (PCOS);
- hirsutism and other manifestations of hyperandrogenism in women;
- monitoring of hormonal therapy.
Method
Mathematical calculation of free testosterone based on serum concentrations of total testosterone and SHBG using clinically validated algorithms.
Procedure
The test is performed using a venous blood sample collected by venipuncture. The sample is processed in the laboratory, and the free testosterone value is calculated based on the measured parameters.
Sources:
https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=testosterone_free
https://www.medichecks.com/blogs/testosterone/what-s-the-difference-between-total-and-free-testosterone
https://www.webmd.com/a-to-z-guides/testosterone-test
IMPORTANT!
It is essential to remember that the information provided in this section is not intended for self-diagnosis or self-treatment. If you experience any symptoms or a worsening of your condition, it is crucial to consult a healthcare professional for proper diagnostic tests and treatment. Only a qualified specialist can make an accurate diagnosis and determine appropriate treatment. To ensure the most accurate and consistent evaluation of test results, it is recommended to have them conducted at the same laboratory. Different laboratories may employ varying methods and units of measurement for similar tests.
Preparation:
Blood sampling is recommended in the morning, between 7: 30–11: 00, preferably in a fasting state.
Within 24 hours before the test:
- avoid intense physical activity
- avoid alcohol consumption
The patient must inform the physician or laboratory staff about any ongoing treatments, especially:
- hormonal therapies
- androgens and anti-androgens
- glucocorticoids
- opioids
- anticonvulsants
- other medications that may affect testosterone or SHBG levels
Do not discontinue any medication without medical advice.
For women with a regular menstrual cycle:
- testing is usually performed on days 2–4 of the cycle
- exception: if otherwise recommended by the treating physician
For men:
- a low testosterone level should be interpreted in a clinical context
- results are usually confirmed with a repeat morning sample
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