The safety of caffeine pills often depends on how much you take. High amounts of caffeine in a caffeine pill can cause symptoms like dizziness, irritability, nausea, and rapid or irregular heartbeat.

We’ve built a complex culture around caffeine. Not only do we have a variety of caffeinated products such as coffee, tea, ...

In one study, researchers monitored the sleep of a dozen volunteers. Some were given a caffeine pill equivalent to about four cups of coffee and others received a placebo instead. Even when the ...

One period involved taking three tablets of caffeine each day and the other period involved placebo tablets. At the end of each program the participants' gray matter volume was measured through ...