How long does caffeine stay in your system? Well, there isn’t a set answer as there are a lot of factors which can play a role in how long caffeine will keep you awake. The half-life of caffeine is approximately 5 hours, however factors such as age, body composition and your overall sensitivity to caffeine can affect how you react to it. If you don’t want caffeine to keep you awake at night, try to avoid drinking coffee in the late afternoon or switch to a decaf product.
If you want to flush caffeine out your system, drink plenty of water. Caffeine is a diuretic, which means you need to drink extra water to make up for what you’re peeing out. You don’t want to get dehydrated. If you feel a lot of pent up energy, take a walk to expend some of it. But if you notice anything unusual happening to your heart rate, like a sudden rapid increase, then stop and practise deep breathing.