Few compounds we consume so regularly seem as complicated as caffeine. The fatigue-fighting component of morning coffee and the pick-me-up part of many energy drinks, the stimulant is the most popular psychoactive drug in the world. In the United States, 90 percent of the population consumes it in some form every day.

But oh, how it confuses. The great caffeine conflict. It’s been blamed for everything from anxiety and insomnia to hypertension and increasing cancer risk; meanwhile, it’s been lauded for everything from exuberant antioxidant levels and increasing longevity to lowering diabetes and reducing cancer risk.

To that end, someone around here has looked at the bulk of research and concluded that caffeine in moderation is a fine (and actually healthy) idea. But where does moderation end and overindulgence begin? To that end, can too much kill you, and if so, how much is too much?

A lawsuit against the makers of Monster energy drink over the death of 14-year-old Anais Fournier — whose autopsy cites “caffeine toxicity” as a contributing factor — recently brought the question to light. As have reports of a rash of deaths potentially linked to 5-Hour Energy drinks.

The actual amount of caffeine that constitutes a lethal dose varies according to whom is asked. Jack James, the editor in chief of the Journal of Caffeine Research, told PopSci.com that overdose for adults requires roughly 10 grams of caffeine, while other sources put the number closer to five or six grams. Which would mean somewhere around 100 cups of coffee.

Since it is safe to assume that people suffering caffeine toxicity aren’t gulping down 100 cups of coffee in one sitting, toxicologists are looking at energy drinks as the culprit behind the increasing number of reports of caffeine-related symptoms such as hallucinations, seizures and arrhythmias.

"In the past it was generally accepted that it is virtually impossible for a normal, healthy person to consume a lethal dose of caffeine when taken in one of its usual dietary forms," says James. "Nevertheless, of the many thousands of cases of caffeine exposure registered with the American Association of Poison Control Centers alone, some do indeed result in death. Until the advent of energy drinks, essentially all of the many reports of lethal and near-lethal cases of caffeine poisoning, involved atypical methods of ingestion. The advent of energy drinks appears to have changed that profile."

So back to the question at hand: How much caffeine would it take to kill you? According to the online Death by Caffeine calculator (where would we be without the Internet?), this is the breakdown of lethal doses for a person weighing 150 pounds:

2047.50 cups of Hot Cocoa

301.10 cans of Coca-Cola Classic

217.82 cups of Brewed Tea

132.95 shots of Espresso

127.97 cans of Red Bull

95.23 cups of Brewed Coffee

63.98 cans of Monster Energy Drink

20.48 2-ounce bottles of ALRI Hypershot workout supplement

19 ounces of 5150 Juice unflavored liquid caffeine concentrate

Since the lethal dose of caffeine for hot cocoa would ring in at around 338,000 calories, we're guessing caffeine isn't going to be your biggest concern in that scenario. Likewise, 50 cups of coffee would likely have you too jittery to get to the lethal dose of 100. The 5150 Juice? A product like that is better suited for sending rockets to Mars rather than combatting the afternoon slump — dabbling in that seems like playing with fire. But to each his own ...

The bottom line is that unless you have very extreme habits or seek your thrills via explosive energy drinks, you will probably not suffer from death by caffeine. That said, everyone has a different reaction to the chemical. If you experience symptoms of caffeine overdose, call the National Poison Control Center (1-800-222-1222) or go to the emergency room.