A Massachusetts congressman wants to take the pep out of energy drink commercials.

In a letter sent to Federal Trade Commission Chairman Jon Leibowitz on Friday, Rep. Edward J. Markey, D-Mass., called for an investigation into advertising claims made by popular energy drinks such as 5-Hour Energy, Monster Energy Drink and Rockstar Energy. Web, print and TV ads for such drinks have become more and more commonplace in recent years, but claims that energy drinks make consumers feel “sharper and more alert” have not been substantiated by the Food and Drug Administration.

Moreover, Markey wrote that those claims are “particularly alarming” in light of the increase in energy drink advertisements aimed at children and teenagers. The congressmen said he believes an investigation is warranted under the FTC’s mandate to protect consumers from “unfair or deceptive acts or practices.”

“Many energy drinks ... are sold as dietary supplements,” Markey wrote. “As a result, these products do not fall under the same federal caffeine limitations that the FDA has issued for beverages such as soda.”

Markey goes on to say that energy drinks contain on average between 160 to 500 milligrams of caffeine per serving, compared with 71 milligrams in a typical 12-ounce can of soda. The makers of 5-Hour Energy do not divulge how much caffeine the drink contains. However, a 2010 analysis from ConsumerLab.com, reported by Consumer Reports, revealed that a 2-ounce “shot” of the product contains 207 milligrams of caffeine. A 12-ounce cup of Starbucks coffee, meanwhile, contains about 260 milligrams.

Markey’s criticism that energy drinks are aimed at children and teenagers mirrors a tactic used by lawmakers to curb advertising by tobacco companies. Joe Camel, the hip, pool-playing cartoon mascot of Camel cigarettes, came under similar fire in the 1990s, following a report by the Journal of the American Medical Association showing that children as young as six were already associating the cartoon camel with cigarette smoking. Camel retired the character in 1997 under mounting pressure from Congress.

Energy drinks have come under increasing scrutiny in recent years as their popularity has exploded, although it is not clear if they are any more harmful than other caffeinated beverages when used as directed. In his letter, Markey points to a Nov. 14 New York Times article citing the possible involvement of 5-Hour Energy in 13 deaths that occurred over the last year. The report was based on filings to the FDA in which the drink was cited; however, the filings do not say that the drink was responsible for the deaths.

The Times reports that, since 2009, 5-Hour Energy has also been cited in 30 FDA filings that involved serious or life-threatening injuries such as heart attacks and convulsions.

Living Essentials, the company that distributes 5-Hour Energy, has denied that it markets its product to children or teenagers. “5-Hour Energy is a compact-sized energy shot intended for busy adults,” company spokesperson Elaine Lutz said in a statement. “It is not an energy drink, nor is it marketed as a beverage.”

In his letter, Markey requested a response from the FTC addressing his concerns by Dec. 14.