Multiply that by two for a more realistic serving size, and you're talking 40 milligrams. Add some chocolate sprinkles or hot fudge, and again you up the ante. One ounce of milk chocolate contains up to 15 milligrams of caffeine, compared with the 35 milligrams in one ounce of dark chocolate. Another unexpected caffeine source is certain pain relief medications. Excedrin and Anacin, for example, contain anywhere from 32 to 100 milligrams in a single tablet.
Caffeine can be effective in helping to alleviate some types of headaches.
How much caffeine is too much really depends on your individual tolerance. For some, the 9 milligrams in a milk chocolate bar will go without notice. But a person who is extremely sensitive or who's had too much may experience side effects, such as an elevated heart rate, nausea and vomiting, restlessness, anxiety, depression, tremors, and difficulty sleeping. If you have any of these symptoms, talk to your doctor, who can determine if you're indeed sensitive to caffeine. But if you're not, a little caffeine now and then isn't likely to harm your health.