How does caffeine affect your sleep? Caffeine is most commonly found in beverages. Caffeine levels in an eight-ounce cup of coffee range from 95 to 200 mg. A 12-ounce soda, by contrast, contains 35-45mg, or around half the amount of caffeine in a weaker cup of coffee. Caffeine is a naturally occurring psychoactive drug found in many foods and drinks around the world. Caffeine can be present in coffee beans, tea leaves, cacao pods, and kola nuts, among other plants. Caffeine, which has energizing and alertness-promoting properties, is also synthesized and used in drugs and energy drinks. How long after caffeine can you sleep? Caffeine shortens the time spent in slow-wave sleep, a deep, restful stage of sleep that leaves us feeling refreshed and alert in the morning. Caffeine-interrupted sleep will result in sleep deprivation the next day, resulting in exhaustion and difficulties with learning, memory, problem-solving, and emotion control. How does caffeine affect the ne