Caffeine is often considered the world’s most widely used psychoactive substance, and its effects on the body can be significant: 1. Constricts Blood Flow: Caffeine acts as a vasoconstrictor, reducing blood flow to the brain and skin, which can lead to a temporary brightening effect but may also contribute to a dull complexion over time. 2. Dehydration: Caffeine can dehydrate the skin, leading to dryness and increased visibility of fine lines and wrinkles. This dehydration can also cause skin re