Energy drinks have become common place next to coffee for people needing an extra boost.
However, the amount of caffeine in the canned drinks may be more than what is listed on the label, according to a new study released last week by Consumer Reports.
The report found the amount of caffeine was not specified in 11 of the 27 best-selling energy drinks in the United States.
The other 16 drinks listed the amount of caffeine, but it wasn't always the correct figure. Five of the 16 drinks had more caffeine with an average of 20 percent more than the listed amount.
In the Consumer Report analysis, a representative for Monster energy drinks said that beverage companies do not have to say how much caffeine is exactly in their drinks because there "is no legal or commercial business requirement."
The Monster rep added that there beverages are not harmful and defended the practice.
"And because our products are completely safe, the actual numbers are not meaningful to most consumers."
The report was cited by Senators Dick Durbin, D-Ill. and Richard Blumenthal, D-Conn. who are urging the Food and Drug Administration to regulate the production and sale of energy drinks, according to USA Today. The two U.S. Senators say the high amounts of caffeine are dangerous and addictive.
The ranges for caffeine levels started at around six milligrams per serving found in Living Essentials popular 5-Hour Energy Decaf and went up to 242 milligrams for their highly potent 5-Hour Energy Extra Strength.
Some of the other drinks that the report found to have more caffeine than their label's list were Arizona Energy, Venom Energy, Nestle Jamba, and Sambazon Organic Amazon Energy.
The Inquisitr reported that Mike Gimbel, a drug expert, warned about the increased sizes of the beverages being sold: "The problem is the caffeine level on these drinks keeps getting larger and larger and larger because of the combination of pure caffeine and the herbal supplements. So when you think of say two plus two, it's two plus 10."