Caffeine is the active ingredient in coffee that keeps you alert. Depending on the time of day, this might be beneficial or detrimental. A regular cup of drip coffee has around 95 mg of caffeine. This number is probably meaningless to you. A cup of tea or a drink has around half as much caffeine. Caffeine levels in energy drinks are comparable. Caffeine has a varied effect on everyone. You can also become accustomed to it. So, if you consume coffee on a regular basis, one cup won’t have the same effect on you.
