When to stop drinking coffee based on YOUR genetics
CYP1A2 determines how fast you clear caffeine from your blood. But the adenosine receptor gene ADORA2A determines how sensitive your brain is to whatever caffeine remains.
The ADORA2A TT genotype (rs5751876) is associated with heightened caffeine sensitivity and increased anxiety response. Carriers report sleep disruption even at relatively low blood caffeine levels.
Translation: Even fast metabolizers can be caffeine-sensitive if they carry ADORA2A TT. If you clear caffeine quickly but still feel wired, your receptor sensitivity may be the bottleneck, not your metabolism. Consider using a lower disruption threshold (20-30mg) in this calculator.
For educational purposes only. Individual caffeine metabolism varies based on genetics, medications, liver health, age, and other factors. This calculator uses population-average pharmacokinetic parameters. Consult a healthcare professional for personalized advice.