What to watch with CYP2D6 and Müdigkeit?

CYP2D6 is a key phase I drug-metabolizing enzyme, responsible for breaking down ~20–25% of common medications, including antidepressants, antipsychotics, beta-blockers, opioids, and some antihistamines. A 'poor metabolizer' phenotype can lead to elevated drug levels, increasing the risk of side effects such as fatigue. Conversely, 'ultrarapid metabolizers' may have subtherapeutic levels, potentially causing fatigue from untreated symptoms. However, fatigue is not a direct genetic effect of CYP2D6; it is an indirect, medication-dependent signal. Without knowing your current medications or supplements, the genotype alone cannot predict fatigue. The MyBody-X test provides the genotype, but interpretation requires medical supervision. Evidence: unclear – strong pharmacogenetic data exist for CYP2D6, but the specific link to fatigue is not well-supported. Caveat: Do not change any medication or supplement dose without consulting a healthcare professional.