What to watch with CYP1A2 and fatigue?

CYP1A2 is a key enzyme for metabolizing caffeine and certain drugs. Genetic variants (e.g., rs762551) classify people as fast or slow caffeine metabolizers. In the context of fatigue, slow metabolizers may experience prolonged caffeine effects that disrupt sleep, worsening exhaustion. Fast metabolizers may get less alertness boost from caffeine. However, the evidence is mostly mechanistic and observational; no strong clinical trials directly link CYP1A2 variants to fatigue management. Other causes like poor sleep, stress, iron deficiency, or thyroid issues are often more significant. A DNA test alone does not warrant specific dietary or supplement changes. Practical advice: monitor your caffeine sensitivity, avoid late-day caffeine if sleep is affected, and prioritize sleep hygiene. For persistent fatigue, consult a healthcare professional for a full workup.