Free and Bioavailable Testosterone
What does this mean?
- Total Testosterone: The total amount of testosterone measured in your bloodstream.
- Free Testosterone: The small proportion of testosterone that is not attached to proteins and is immediately available for your body to use.
- Bioavailable Testosterone: The testosterone that is available to your body, including free testosterone and testosterone that is loosely attached to albumin.
- SHBG (Sex Hormone Binding Globulin): A protein that binds to testosterone. Higher SHBG levels can reduce the amount of testosterone available for your body to use, even when total testosterone appears normal.
- Albumin: A protein found in your blood that carries testosterone around the body. Testosterone attached to albumin can still be used by your tissues.
Use the Harley Street TRT tool to estimate your free and bioavailable testosterone from your total testosterone, SHBG, and albumin blood test results. This can help provide a clearer picture of the testosterone available to your body, particularly when total testosterone alone does not tell the full story.
Why symptoms matter
Testosterone levels are only one part of the picture.
Some men with testosterone levels outside the normal range experience very few symptoms, while others may experience symptoms despite results that appear normal. Symptoms that may be associated with low testosterone include:
Reduced body and facial hair.
Loss of muscle mass.
Flabby pectoral muscles.
Low libido, erectile dysfunction, and changes in testicular size (in some cases).
Hot flushes.
Irritability, poor concentration, and low mood.
Disturbed sleep patterns.
Weight gain.
Brittle bones and an increased risk of fracture.
Reduced sperm count and infertility.
Understanding your result
Your calculated free and bioavailable testosterone levels may provide additional information alongside your total testosterone result.
Results should always be interpreted together with:
- Your symptoms
- Medical history
- Current medications
- Other hormone and blood test results
A calculator cannot determine whether testosterone replacement therapy is appropriate or whether symptoms are caused by low testosterone levels.
Book a Consultation
Book your consultation with one of our TRT experts. You can choose to have your consultation online or in-person. If you decide to have an online consultation, you will receive a Zoom link after booking.
After booking, you will be asked to complete the *qADAM assessment, which evaluates symptoms related to testosterone levels. The questionnaire will be sent to you via the email confirmation of your booking. Additionally, you will be required to take a blood test to check your testosterone levels. If you have completed a blood test within six months prior to your consultation, you can also submit those results.