Evidence check: Testosteron Test in the context of fatigue

The evidence for testosterone testing in the context of fatigue is moderate. Low testosterone can be associated with fatigue in men, but fatigue is a non-specific symptom with many causes (e.g., sleep deprivation, stress, thyroid dysfunction, iron deficiency). Endocrine society guidelines recommend testing only when other signs of hypogonadism are present (e.g., low libido, erectile dysfunction, testicular atrophy). In women, the link between testosterone and fatigue is weak, and routine testing is not advised. Direct-to-consumer tests often overstate the clinical significance of minor deviations. A single testosterone value without a thorough medical history is not diagnostic. Evidence is based on observational studies and clinical guidelines, not on RCTs of testing for fatigue. Conclusion: Testosterone testing may be useful when hypogonadism is suspected, but not as a general screen for fatigue.