Test Guide
Best Blood Test for Testosterone (Men 30+, UK)
Testosterone naturally declines by around one percent per year from your 30s onwards. For some men the drop is significant enough to cause symptoms: low libido, fatigue, loss of muscle, mood changes, poor sleep. A blood test is the only reliable way to know your baseline. This guide explains what to test, when, and which Chxhealth panels make sense.
What to actually measure
Total testosterone is the standard first test but tells only part of the story.
SHBG (sex hormone binding globulin) binds testosterone in the blood and renders it inactive. SHBG rises with age, so two men with the same total testosterone can have very different free, biologically active testosterone.
Free androgen index (FAI) is calculated from total testosterone and SHBG. It estimates how much testosterone is biologically available.
Together these three give a much clearer picture than total testosterone alone.
When and how to test
Always test in the morning, between 8am and 10am. Testosterone naturally peaks in the morning and drops 20 to 30 percent through the day. Afternoon readings can produce a false low.
Fast for 12 hours, water only. Avoid strenuous exercise for 24 to 48 hours beforehand.
If your first reading is borderline low, retest on a separate morning before drawing any conclusions.
What about TRT (testosterone replacement therapy)?
Many men on TRT use a testosterone panel to track levels alongside their prescribing clinician. Chxhealth provides the data; treatment decisions stay with your clinician.
Chxhealth is a biomarker and genetic data provider. We do not diagnose, treat or prescribe. Our service supports your wellbeing journey alongside your healthcare professional.
Best Chxhealth panels for this
The Chxhealth panels below are designed for the markers discussed above. Each comes with a plain English PDF report, lab analysis by Randox (UKAS, ISO 15189), and the phlebotomy fee included in the price.
Testosterone Monitoring
Focused panel covering total testosterone, SHBG and free androgen index. The standard starting point.
Endocrinology
Wider hormone view if you want to see thyroid and cortisol alongside testosterone.
Endocrinology Plus
Most comprehensive male hormone panel. Best for over-45s or complex symptoms.
Standard Screen Plus + Hormonal Health
If you want a general health baseline alongside hormone testing.
Related biomarker guides
Read more about the specific markers discussed in this guide:
FAQs
What is a normal testosterone level for a UK man?
Adult male reference ranges are typically 10 to 30 nmol/L. Below 10 nmol/L is generally considered low and worth investigating, particularly with symptoms.
Does morning testing really matter?
Yes. Testosterone follows a daily rhythm and drops 20 to 30 percent through the day. NHS and most clinical guidelines specify morning testing for diagnostic purposes.
Will the test tell me if I need TRT?
No. Chxhealth is a biomarker and genetic data provider. We do not diagnose, treat or prescribe. Our service supports your wellbeing journey alongside your healthcare professional. The test shows your levels relative to reference ranges. TRT decisions must be made by a clinician based on symptoms, repeat testing and your full clinical picture.
Can I take this if I already use TRT?
Yes, many men use it to monitor levels alongside their prescribing clinician. Test at the time of day your clinician recommends for monitoring (often before your next dose).
About this guide. Educational content for general awareness. Chxhealth is a biomarker and genetic data provider. We do not diagnose, treat or prescribe. Our service supports your wellbeing journey alongside your healthcare professional. For medical advice about your health or results, please speak to a qualified clinician.