For many bleary-eyed people, it’s about as important as the sun itself. Others are trying their best to cut back. So which is it: Is caffeine bad for you? Or the best thing ever?

Whether you view its powers as a virtue or a vice, caffeine is complicated. It’s a daily ritual, a cultural experience, and a historic medicine. It can wake you up in the morning, or keep you up at night. And while it’s widely consumed, it’s also wildly misunderstood. Let’s get the whole story of this mysterious little stimulant, shall we?

Grab some coffee. It’s time for some science.

Caffeine is a naturally occurring stimulant found in more than 60 types of plants, like tea leaves and coffee beans. It’s absorbed through the stomach, distributed through the body, and gets down to business when it reaches the brain.

“Caffeine has a direct link to your central nervous system, which is essentially the engine of your brain,” says Vishal Patel, Director of Product Development at Nuun. Caffeine directly impacts serotonin production, which is involved in fatigue and mood regulation, and helps release dopamine, the so-called “happiness hormone.”

"It’s not just that it gives you energy and alertness,” says Patel. Caffeine really has a direct impact on your mood.” No wonder a simple cup delivers such bliss.  

Let’s cut to the chase: Is caffeine bad for you?

Every individual responds to caffeine differently, and the research indicates that caffeine sensitivities can be genetic.

“Caffeine is a stimulant, so overconsumption can lead to some side effects like jitters and increased heart rate,” says Patel. “Some people just have a lower tolerance, so they just feel the side effects more.”

But beyond those well-known side effects and the classic caffeine crash, it hasn’t been found to cause real harm or illness, such as cancer. Instead, studies have revealed some positive effects, like improving cognitive function.

So…there are actually some health benefits of caffeine?

Yes! “Caffeine does have benefits,” says Patel. “Tons of studies have shown the efficacy of caffeine both in your day-to-day life as well as in exercise." In fact, its powers in exercise are so pronounced that it was deemed a banned substance for Olympic athletes until 2004.

"Caffeine does have benefits. Tons of studies have shown the efficacy of caffeine both in your day-to-day life as well as in exercise."