Low testosterone: why one blood test isn't enough

A single low testosterone reading on its own is not enough to decide whether treatment is needed. In a statement dated 16 July 2026, the Endocrine Society reinforced that a diagnosis of low testosterone should be based on both symptoms and confirmed, repeat blood testing.

Symptoms such as fatigue, low mood, reduced drive, or changes in body composition can have many causes. Testosterone results need to be interpreted alongside how you actually feel and your wider health, not in isolation.

Testosterone levels naturally fluctuate through the day, with the highest levels in the early morning. A single afternoon reading can appear low even when morning levels are normal, which is why repeat early-morning, fasting measurements are recommended before any conclusion is drawn.

Confirming a genuinely low result with a second test helps avoid starting treatment on the basis of a one-off reading that may not reflect your true level.

A broader blood screen helps assess your general health and can identify possible causes of low testosterone, such as other hormone imbalances or underlying health conditions. It also helps confirm whether testosterone therapy would be safe and appropriate for you.

One low result does not automatically mean you need TRT. The decision to treat depends on confirmed deficiency, your symptoms, and a careful assessment of your overall health and any relevant risks.

Our pathway begins with an initial testosterone blood test and a consultation to understand your symptoms and health history. Where results are low or borderline, we arrange a repeat test within a fuller screening panel to confirm the finding and assess your overall health.

Only after reviewing both sets of results alongside your clinical assessment do we discuss whether treatment is appropriate and agree an individual plan. If TRT is not suitable, we explain the reasons and discuss alternative next steps.