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Hormones

Free Testosterone

LOINC 2991-8 · pmol/L

What it is

Free testosterone is the small portion of testosterone not bound to proteins — the part readily available to your tissues.

Why it matters

It can give a clearer picture of active testosterone than the total, especially when binding proteins are altered.

What high values can mean

A higher value can relate to certain hormonal conditions and may cause symptoms such as acne or, in women, excess hair growth.

What low values can mean

A lower value can cause low energy, reduced libido or mood changes and is more common with age.

How to improve it

Healthy weight, strength training, good sleep and managing chronic conditions support healthy testosterone.

Food & lifestyle

Adequate sleep, resistance exercise and a balanced diet support hormone balance; supplements are not a substitute for evaluation.

Preparing for the test

Best drawn in the morning when testosterone peaks; follow your lab's instructions.

When to talk to a doctor

Discuss abnormal free testosterone with a doctor, interpreted with total testosterone and SHBG.

Related markers

Sources

  • MedlinePlus (NIH)
  • Testing.com (AACC)

Content reviewed on June 26, 2026

Medical disclaimer

This content is for educational purposes only. It is not medical advice and does not diagnose, treat, or prevent any condition. Reference ranges vary between laboratories — always use the range printed on your report and discuss your results with a healthcare professional.

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