Testosteron Test: can a DNA test help?

A DNA test for testosterone is not scientifically useful. The genetic variants offered in some consumer tests (e.g., in genes like SHBG, CYP19A1, or AR) have only very weak and often contradictory effects on actual testosterone levels. Studies show that while testosterone heritability exists, it is polygenic with many tiny effect sizes – no single SNP can predict a clinically relevant deficiency or excess. Moreover, testosterone is heavily influenced by lifestyle, age, sleep, diet, stress, and time of day. A genetic test cannot capture these factors. For a valid assessment of testosterone status, a blood test (total and free testosterone, SHBG) is required, ideally taken in the morning while fasting. The evidence for DNA-based testosterone tests is best classified as 'marketing' or 'unclear.' Anyone with genuine symptoms should consult a physician rather than rely on genetic testing.