The FDA does not require energy drink companies, including Monster, to list the exact amount of caffeine on ingredient labels because the products are regulated as dietary food supplements instead of food. Energy drinks are also sold as nutritional supplements, even though they may not have any nutritional value. Because of this regulation, energy drinks may exceed the FDA-mandated limit of 71 milligrams of caffeine for a 12-ounce soda. As well, the FDA does not allow soda to have more than 0.02 percent caffeine, but energy drinks aren’t subject to this limit.