When is Haarausfall Labor actually useful?

A hair loss lab test (e.g., blood levels of iron, zinc, vitamin D, thyroid hormones, sex hormones) is useful when there is clinical suspicion of a treatable underlying cause – such as iron deficiency, thyroid dysfunction, or hormonal imbalance. In these cases, lab work can guide targeted therapy. Genetic tests for hair loss (e.g., AR gene, androgen receptor) are generally not clinically actionable: they indicate increased risk for androgenetic alopecia, but treatment (e.g., minoxidil, finasteride) is based on clinical presentation, not genotype. Evidence for the utility of genetic testing in hair loss is weak (mechanistic, no RCTs). Many direct-to-consumer tests overstate individual benefit. A physician should interpret results in clinical context. Safety note: Sudden or patchy hair loss requires medical evaluation (e.g., for autoimmune conditions) before any lab testing.