What role does CYP1A2 play in Schlaf?

CYP1A2 encodes a liver enzyme that metabolizes caffeine. The rs762551 variant (C allele) defines 'slow' metabolizers, who clear caffeine more slowly, leading to prolonged stimulant effects that can impair sleep onset and reduce deep sleep. However, the direct role of CYP1A2 in sleep is indirect and entirely mediated by caffeine intake. Without caffeine, CYP1A2 genotype has no established effect on sleep architecture. Evidence is mechanistic and observational; no strong clinical trials link CYP1A2 variants to sleep disorders independently. Consumer DNA tests often overstate this association. Practical takeaway: if you are a slow metabolizer, avoid afternoon caffeine to protect sleep. But sleep hygiene, light exposure, and stress are far more impactful than this single SNP.