Does 5-Hour Energy really work?

Does 5-Hour Energy really work?

Last updated: February 2011

"What's your 2:30 feeling like?" asks a TV ad for 5-Hour Energy, a roughly 2-ounce, caffeinated, liquid energy "shot." Cue video of a woman toting an armful of files up the office stairs. "I can barely keep my eyes open," she groans. But after she downs the 4-calorie, sugar-free, fruit-flavored dietary supplement, she perks up. "It's me," she says, "just a better, more awake me."

How good is the evidence that 5-Hour Energy "provides a feeling of alertness and energy"? A company spokeswoman let us view a summary of a randomized, double-blind controlled clinical trial involving 90 adults who were tested over 6 hours. The company-funded study supported the claim that 5-Hour Energy "significantly outperformed" a placebo in tests measuring attention and alertness, but it hasn't been published in a peer-reviewed scientific journal, which screens for biases.

A spokeswoman wouldn't disclose the exact amount of caffeine in the product but said that it's comparable to the amount in "a cup of the leading premium coffee." Consumer Reports hasn't tested 5-Hour Energy. But an October 2010 analysis by, an independent group that conducts product evaluations, found that it contained about 207 milligrams of caffeine. (An 8-ounce serving of Starbucks coffee has 180 milligrams of caffeine, according to the company’s website.) The 5-Hour Energy spokeswoman had no comment on the report. We found little if any research showing that other ingredients on the label—including B vitamins and amino acids—would give the average person a boost.

Bottom line. 5-Hour Energy will probably chase away grogginess at least as well as a cup of coffee. The label warns against drinking more than two bottles daily. Avoid it if you're pregnant or nursing, and don’t give it to kids.

This report was made possible by a grant from the Airborne Cy Pres Fund, which was established through a legal settlement of a national class-action lawsuit (Wilson v. Airborne Health, Inc., et al.) regarding deceptive advertising practices.

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