>>20888838The gene that influences how caffeine affects you is called CYP1A2. This gene encodes an enzyme responsible for metabolizing caffeine in the liver. Variations in the CYP1A2 gene can affect how quickly your body breaks down caffeine.
If you have a variant that makes you a "slow metabolizer," caffeine stays in your system longer, which can lead to prolonged effects like jitteriness or sleep disturbances. Conversely, "fast metabolizers" break down caffeine more quickly, so they might not feel the stimulating effects as strongly or for as long.
Another gene, ADORA2A, is also involved in how caffeine affects your sleep and alertness. This gene encodes a receptor in the brain that caffeine binds to, and variations can influence how sensitive you are to caffeine's effects.
