Women generally metabolize caffeine faster than men.
It’s not just coffee beans: tea leaves, kola nuts (which flavor colas) and cocoa beans all contain caffeine. The stimulant is found naturally in the leaves, seeds and fruits of a wide variety of plants. It can also be manmade and added to products.
According to one FDA report, more than 98 percent of our caffeine intake comes from beverages. But those aren’t the only sources of caffeine: certain foods, such as chocolate (though not much: a one-ounce milk chocolate bar contains only about 5 mg of caffeine), and medications can also contain caffeine. Combining a pain reliever with caffeine can make it 40 percent more effective, the Cleveland Clinic reports, and can also help the body to absorb the medication more quickly.
Though caffeine can actually trigger headaches in some people, for most of us it is an effective headache therapy. It is bundled into a number of prescription migraine medications, and is a key ingredient in over-the-counter analgesics like Excedrin and Anacin. That’s not too surprising. What is surprising that it is now being marketed specifically to treat a dreaded malady — the hangover headache.