Caffeine is the world’s most widely consumed psychoactive drug. Caffeine keeps you awake by halting the effect of the neurotransmitter adenosine. When adenosine binds to receptors in your brain it makes you feel tired. Caffeine binds to the receptors that adenosine would usually bind to, which means adenosine can’t have its effect. This stops you from feeling drowsy.
Ring sizes: 6.5 & 10