Evidence check: Eisen-Ferritin Selbsttest in the context of Schlaf

The iron-ferritin self-test measures stored iron (ferritin) in capillary blood. Low ferritin (<30–50 µg/L) is associated with Restless Legs Syndrome (RLS) and poorer sleep quality, as iron is crucial for dopamine synthesis and myelination. The evidence for this link is human-moderate: numerous observational studies and small trials show that iron supplementation in ferritin deficiency can reduce RLS symptoms and improve sleep. However, ferritin is an acute-phase reactant; inflammation, infection, or liver disease can falsely elevate levels. A self-test cannot diagnose sleep disorders—it only identifies a potential risk factor. Sleep problems are usually multifactorial (stress, light, genetics, other deficiencies). Interpretation should always be done by a physician, especially before iron supplementation, as iron overload is toxic. The test is useful as a screening tool but insufficient for clinical decision-making in sleep. Evidence: human-moderate for the iron-sleep connection, but the test itself is a practice/marketing product with limited clinical validation in the sleep context.