Caffeine's half-life is between 4 and 6 hours, according to the FDA. This means that you can continue to feel alert for up to six hours after consuming a caffeinated beverage because half of the caffeine is still in your system. If it's bedtime, a coffee from 6 hours prior can be what’s preventing you from dozing off. The fastest way to get the caffeine out of your system is to drink lots of water and stimulate your metabolism. Aim to drink 8 to 10 glasses of water per day, as this will help to flush out caffeine by increasing urination. Additionally, light exercise stimulates your metabolism and increases blood flow, which will help the body eliminate the stimulant quicker. If you have difficulty getting caffeine out of your system, consult our team at a Koala Center For Sleep & TMJ Disorders to determine a treatment plan for your caffeine-induced insomnia.