The modern market for energy drinks is less than 20 years old, but the products are already firmly rooted in the dubious tradition of American patent medicine. We’ve always had a weakness for elixirs and potions that promise health and vitality, but nowadays, we get our nostrums from the convenience store rather than the travelling medicine show. If you wanted to sum up energy drinks, you could put it this way: A middling amount of caffeine combined with mega-doses of marketing and pseudoscience. But while the market has experienced incredible growth over the past two decades, an accumulation of deaths ostensibly caused by energy drinks, an FDA investigation, and the general tenor of public alarm suggests that the honeymoon phase is over. But should we really be worrying?

Since their inception, the marketing of energy drinks had been tied up in the idea of excitement and rebellion. With names like “Monster,” “Rockstar,” and “Cocaine,” these drinks are marketed to appeal to those with a taste for danger. Red Bull, a privately held company, is rumored to spend 40 percent of its revenue on marketing, including sponsorships of extreme sports and spectacular stunts like Felix Baumgartner’s 128,100-foot parachute jump from the edge of outer space. Red Bull swore Baumgartner’s leap into the abyss was a serious mission to expand human knowledge, but like most aspects of the energy drink industry, the real focus was on showmanship.

These tactics seem to have worked. The U.S. market for energy drinks has grown dramatically since the launch of Red Bull in 1997. Despite their premium price tag, energy drinks did especially brisk business during the recession; the market grew 60 percent between 2008 and 2012. Today, energy drinks are a $12.5 billion industry, dominated by a handful of big brands: Red Bull commands a 42 percent market share, followed by Monster at 37 percent and Rockstar at 11 percent. In the energy shot category, 5-Hour Energy boasts an astonishing 90 percent market share. Red Bull sells over 1.5 billion cans a year in the United States. Monster estimates that 8 billion cans of its product have been consumed worldwide since 2002.

But all this might soon change. In the fall of 2012, the FDA revealed that it was investigating a series of deaths associated with energy drinks. Between 2004 and 2012, the FDA received five reports of deaths that might have been caused by Monster Energy and 13 that might have been caused by 5-Hour Energy. These reports were grist for Senators Dick Durban and Richard Blumenthal, who have been pressuring the FDA to get tougher on energy drinks. The American Academy of Pediatrics weighed in against energy drinks for children earlier this year. Even the courts may have something to say in the near future. Anais Fournier, a 14-year-old Maryland girl, died of cardiac arrest in December of 2011 after drinking two 24-oz cans of Monster Energy 24 hours. Her parents are suing Monster Energy.1 

Regardless of what regulations are put in place and what the courts decide, should we worry? Most of these drinks are composed of little more than water, sugar, caffeine, and a proprietary blend of vitamins, amino acids, and herbs. As far as the FDA is concerned, “energy” means calories, and most energy drinks have those—but, as Michael Jacobson of the Center for Science in the Public Interest explains, “That’s not what they’re bragging about.” Energy drinks are marketed as “functional beverages,” which supposedly confer increased vigor and concentration. To the extent that caffeine boosts alertness, Jacobson concedes that this is a valid claim.

So just how much caffeine is in these drinks? There are energy shots on the market that boast 500mg of caffeine per serving (about five times the amount in a 5-oz home-brewed cup of coffee), but you’ll be hard pressed to find them at your local corner store. These super-caffeinated concoctions command a very small market share and typically lack national distribution. The leading brands tend to have caffeine levels on par with many of the offerings at your local coffee shop. A typical 16-oz Starbucks Grande drip coffee has 330mg of caffeine; A 16-oz serving of Rockstar has 160mg. A 8.4-oz can of Red Bull actually has just 80mg of caffeine. A 12-oz can of Coke Classic has 35mg.

There is nothing mysterious about why energy drinks perk people up or why they can have side effects; it’s just the caffeine. At high doses, caffeine can cause side effects familiar to anyone who has had too many cups of coffee: tremors, nervousness, nausea, and insomnia. Very high doses of caffeine can cause seizures and heart rhythm abnormalities.2 Members of the American Beverage Association, a trade group that represents energy drink manufacturers and other makers of non-alcoholic beverages, voluntarily caution against the use of caffeinated product by children, pregnant women, and people with caffeine sensitivity.

But there are a few factors that make it harder for consumers to gage the effect of their liquid perk-me-ups. The FDA limits caffeine in carbonated colas to about 71mg per 12-oz can, but it offers no comparable limit for energy drinks. Drinks marketed as beverages must display their caffeine content on the label, but drinks marketed as dietary supplements—which includes many popular energy drinks—escape this regulation. The label may not be an accurate guide, either: A recent study published in Consumer Reports found that five out of 16 energy drinks that listed their caffeine content on the label had at least 20 percent more caffeine than advertised. 

What are we to make of the deaths? They don’t provide as clear a warning as one might suspect. These death reports are based on records in the FDA’s adverse event reporting database. These reports can be filed by anyone and do not necessarily prove that the product caused death or illness. With billions of cans of energy drinks sold, we’d expect a certain number of people to die or have seizures after drinking them, purely by chance. The FDA attempts to follow up on all reports, but some states prohibit the agency from obtaining medical records connected to adverse events. And reporting is slippery: Companies that market their drinks as dietary supplements are legally required to report serious adverse events to the FDA, but reporting is voluntary for companies that market their products as beverages. After the FDA revealed that it would investigate the five potential Monster deaths, Monster Energy announced that it would be reclassifying itself as a beverage.

A widely-cited report by the Drug Abuse Warning Network (DAWN), a public health surveillance project of the Substance Abuse and Mental Health Services Administration (SAMHSA), found that energy-drink-related ER visits doubled between 2007 and 2011, from 10,068 to 20,783.3 This report represents a higher grade of evidence than the FDA’s raw adverse event reports: A health care provider has to indicate that the drink caused the visit, either on its own, or with other substances to register on the DAWN report.4 Unlike the FDA reports, which only come in when someone thinks to submit one, or when a company decides it is legally required to do so, the DAWN study captures all energy-drink-related visits charted at the hospital.

However, the DAWN report doesn't specify the symptoms bringing patients to the ER, or what percentage of them were admitted to hospital. Nor does the report identify patients who have preexisting conditions that might increase their caffeine sensitivity. Furthermore it doesn’t consider the possibility that those who drink energy drinks might be more likely to be risk-takers to begin with; that’s been the energy drink marketing MO from the beginning.

Whatever the ultimate dangers of energy drinks, the FDA should close the dietary supplement loophole and require that all energy drinks list their caffeine content. It might also be worthwhile to set limits on the amount of caffeine that a drink or shot can contain, as Canada has done. Since energy drinks are caffeine-delivery mechanisms, the maximum dose should be pegged to other popular vehicles for high-dose caffeine, like coffee and caffeine tablets.

Broadly speaking, energy drinks are safe for most people in moderation. They’re typically full of empty calories and high in caffeine, but they’re no worse than a lot of popular coffee drinks. The real mystery is why anyone would choke down a syrupy Extra Strength 5-hour Energy shot for $3 when they could get the same dose of caffeine in a NoDoz tablet for pennies, wash it down with a tasty beverage, and still save money.

  1. The company counters that there’s no proof that the drink caused her heart to stop. The official cause of her death was “cardiac arrhythmia due to caffeine toxicity complicating mitral valve regurgitation in the setting of Ehlers-Danlos syndrome.” In other words, Anais had a preexisting heart defect. Caffeine may have put an additional strain on her heart. Monster’s lawyers argue Anais’ caffeine levels were never measured.

  2. Caffeine sensitivity depends on acquired tolerance, genetics, body size, and other factors. People with heart disease and high blood pressure may be at increased risk from caffeine. Most healthy adults can tolerate 400-600mg of caffeine a day without ill effects.

  3. This is still a tiny fraction of the 136 million emergency room visits in the United States each year.

  4. Fifty-eight percent of ER visits were for energy drinks alone and 42 percent of visits involved energy drinks in combination with alcohol or other drugs.