The energy drink industry built a multi-billion-dollar global business on the proposition that its products deliver something fundamentally different from coffee — a combination of stimulants, vitamins, amino acids, and proprietary blends that produces enhanced performance, mental clarity, and sustained energy that caffeine alone cannot provide.

The research has been considerably more skeptical. Study after study examining the specific ingredients in energy drinks — taurine, B vitamins, guarana, inositol, various herbal extracts — has found that when caffeine is removed from the equation, the additional ingredients contribute nothing measurable to the energy or performance benefits that consumers report.

What energy drinks deliver is, in most cases, caffeine. Often substantial quantities of it — a 16-ounce can of a popular energy drink may contain 150 to 200 milligrams of caffeine, comparable to a large cup of coffee. The subjective experience of enhanced alertness and energy that drinkers attribute to the unique formula is the same experience that coffee drinkers have been having for centuries.

This would be an innocuous deception if the products were simply expensive ways of consuming caffeine. The concern that has attracted regulatory attention is the marketing of these products to adolescents and young adults, often through sports sponsorships and extreme sports associations, and the pattern of consumption — often multiple cans in succession — that results in caffeine intake levels associated with cardiac arrhythmia, anxiety, and sleep disruption.

The combination of energy drinks with alcohol, marketed explicitly as a way to maintain alertness while drinking, has attracted particular concern from public health researchers who found that the combination was associated with higher rates of dangerous drinking behavior. Several formulations were removed from the market following regulatory pressure.

Energy drinks work. They work because they contain caffeine. The rest is marketing.