Reaction towards caffeine differs from person to person. Some may have trouble falling asleep and others may be fine. This is because everyone has different caffeine metabolism.

The ability to breakdown caffeine is partially dependent on your genes.

You might not be able to metabolize caffeine as fast and as efficiently as others if you have a genetic variant associated with caffeine metabolism.

CYP1A2 and CYP2A6 are genes that contribute to caffeine metabolism. Genetic variants of these specific genes can lead to inefficient caffeine breakdown within the body and potentially cause side effects.

Genes, however, are not the only factor that determines your ability to break down caffeine. Smoking accelerates caffeine metabolism, causing the smoker to crave and drink more coffee.

Generally, recommended daily caffeine intake is 400mg for adults, 300mg for pregnant women, and 2.5mg per 1kg of weight for adolescents.

A dose of caffeine can keep you awake and increase your work performance.
But try to avoid from consuming too much caffeine, as caffeine overdose can cause various side effects including hypertension, shakiness, and racing heartbeat.

Do you tend to have trouble falling asleep when you drink too much coffee?

Genetic analysis test on caffeine breakdown is done in Genoplan Japan.