Testosterone (Free) Test

Reports free testosterone, the portion of testosterone available to tissues. The result may contribute to hormone assessment but should be interpreted with symptoms, collection timing, medicines and any companion hormone tests advised by a clinician.

At a glance

• Sample: Capillary blood in a Gold Microtainer
• Collection: Collect the blood sample at home using TDL self-collect kit KT353
• Estimated turnaround: 3 days from laboratory receipt of a usable sample

What this test measures

Free testosterone

The portion of testosterone reported as available to tissues; the public TDL page does not state whether it is measured directly or calculated. A low or high result may contribute to assessment of androgen status, but collection timing and total testosterone, SHBG and symptoms often provide essential context.

How clinicians use this test

Clinicians use Free testosterone as part of hormone assessment, often with related hormones and carefully chosen collection timing. One value rarely establishes the cause of symptoms by itself.

Is this the right test for you?

An adult exploring the stated hormone marker with a clinician or monitoring an established plan, with collection timing and medicines taken into account.

Preparation and collection

Avoid collecting from any area where hormone-replacement cream is applied. Return the sample on the same day and do not post over weekends or bank holidays.

Understanding your result

The laboratory will report Free testosterone with an assay-specific reference range, threshold or qualitative interpretation. Read the biomarker explanation above for common reasons a result may be high, low, detected or reactive, then use the laboratory comment and clinical context to decide whether repeat or follow-up testing is needed.

Your results and next steps

Review the result with collection timing, medicines and related hormones in mind. Do not start, stop or change prescribed hormone or thyroid treatment from a single home-test result without clinician advice.

Limitations

Hormone values can vary with collection time, age, medicines and biological state. A single result does not establish the cause of symptoms.

When to get medical help

Do not wait for a home-test result if you feel seriously unwell. Call 999 for a life-threatening emergency, or use NHS 111 when you need urgent advice and are unsure what to do.