How exactly does the body process caffeine? Matt Swenson, Director of Coffee at Chameleon Cold-Brew, explains the effects on your nervous system. “Generally, when we get tired, the body begins to release adenosine. These molecules bind to adenosine receptors to tell your body to start winding down and gives the general feeling of tiredness. Caffeine, structurally similar to adenosine, binds to the receptors instead and acts as a stimulant by activating the central nervous system and producing heightened brain activity.” Swenson recommends a cold-brew to get the day started (or get through that afternoon slump, right?).