Caffeine is a bitter, white crystalline purine, a methylxanthine alkaloid, and is chemically related to the adenine and guanine bases of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

Feb 6, 2025 · Experts say up to 400 milligrams (mg) of caffeine a day may be safe for most adults. But if you get headaches or are restless or nervous after having caffeine, you may want …

May 18, 2023 · Caffeine is a natural stimulant most commonly found in tea, coffee, and cacao plants. It works by stimulating the brain and central nervous system, helping you stay alert and …

Mar 21, 2025 · What is caffeine? Caffeine is a type of drug called a stimulant, meaning it increases chemicals in your brain called neurotransmitters.

Caffeine is a natural chemical with stimulant effects. It is found in coffee, tea, cola, cocoa, guarana, yerba mate, and over 60 other products. Caffeine works by stimulating the central...

3 days ago · Caffeine is a central nervous system stimulant. It works by stimulating the brain. Caffeine is found naturally in foods and beverages such as coffee, tea, colas, energy and …

Jun 16, 2025 · Learn about caffeine's effects on the human body. Caffeine has a stimulating effect on the central nervous system, heart, blood vessels, and kidneys. It also acts as a mild …

Read on to learn more about sources of caffeine, and a review of the research on this stimulant and health. The chemical name for the bitter white powder known as caffeine is 1,3,7 …

May 29, 2024 · Caffeine is a naturally occurring central nervous system stimulant belonging to the methylxanthine class and is widely recognized as the most utilized psychoactive stimulant …

Sep 8, 2021 · What is caffeine? Caffeine is a bitter substance that occurs naturally in more than 60 plants including: Coffee beans; Tea leaves; Kola nuts, which are used to flavor soft drink …