What Happens to Your Body When You Consume an Energy Drink?

To stay alert on a long drive, perk up from the afternoon slump, or cram for a test, you might turn to energy drinks. Canned and bottled beverages with ingredients like caffeine, taurine, ginseng, and B vitamins are designed to boost energy by stimulating the central nervous system. In many cases, they really do work to keep you temporarily awake and alert.

But energy drinks have their downsides, too. A growing body of research shows that overconsuming them could raise blood pressure, promote weight gain, cause insomnia, raise cortisol, and more. So is it worth it to regularly down that Red Bull or Celsius for an energy fix? For overall health, many experts advise caution. Here’s a look at what happens to your body when you consume an energy drink.

What Happens to Your Body When You Consume an Energy Drink?

As an energy drink travels through your digestive system, its effects on your body depend on its ingredients. If your beverage uses caffeine as a stimulant, you might start to feel its perking-up effects within 10 to 30 minutes. Similarly, if sugar is a primary ingredient, you might begin to feel energized within about half an hour.

Unfortunately, these results are typically short-lived and the aftermath isn’t necessarily pleasant. Knocking back a high-sugar drink will initially spike your blood sugar (providing energy), but soon enough, your blood glucose will dramatically drop.

“If you're drinking a high-sugar energy drink, after about an hour, you'll likely experience an energy crash related to the sudden drop in blood sugar,” says Lindsey Janeiro, RD, of Nutrition to Fit and Healthy*ish Recipes. When blood sugar drops, you may not only feel tired, but irritable, unfocused, or shaky.

Like sugar, caffeine has a spike-and-drop trajectory of its own, explains Ryann Jung, MS, RDN, of Nutrition With Ryann. “Caffeine works by blocking adenosine receptors in the brain, which are responsible for making us tired. As the caffeine wears off, your brain becomes aware of the adenosine that has been accumulating, and you begin to feel sleepy again.”

Ultimately, relying on energy drinks could leave you yo-yo-ing between excess energy and not enough.

Are Energy Drinks Safe?

Energy drinks have been fraught with controversy due to minimal government oversight. The Food and Drug Administration (FDA) does not regulate energy drinks, though it enforces caffeine limits of 71 milligrams per 12 ounces for drinks considered sodas. However, some energy drink manufacturers classify their products as supplements to get around this rule.

Meanwhile, numerous studies have associated energy drinks with adverse health effects. A Journal of the American Heart Association study found that energy drinks raised blood pressure. Other research published in Frontiers in Public Health related energy drink consumption with risk-seeking behaviors, poor mental health, adverse cardiovascular effects, and metabolic, renal, or dental conditions.

According to the National Center for Complementary and Integrative Health, the number of energy drink-related visits to emergency departments doubled between 2007 and 2011. In 2011, 10% of these visits resulted in hospitalization.

Before you reach for a buzzy beverage, note that individual ingredients also might not be compatible with your health, says Jung. “While ingredients in energy drinks are considered safe when consumed independently, some may pose health risks depending on the dosage and the individual. Herbal extracts, B vitamins, and sugar are just a few added ingredients that could be harmful due to the potential for adverse interactions with medications, vitamin toxicity, and increased risk for developing obesity and type 2 diabetes.”

How to Choose a Healthier Energy Drink

Though some energy drinks market themselves as healthy by being plant-based, gluten-free, all-natural, or organic, these terms don’t always translate to better-for-you products.

“Labels such as plant-based and all-natural simply mean that ingredients are derived from natural sources and do not contain artificial flavors, sweeteners, or synthetic coloring,” says Jung. 

Nutrition facts labels are where you’ll find the true story of each drink’s healthfulness. First, look at the sugar content. To avoid a sugar crash (and keep calories in check), Janeiro recommends choosing drinks with no added sugars.

Next, check a drink’s caffeine content. (Not all drinks include this information on nutrition facts labels, but you can often find it online.)

“Caffeine content varies, but many energy drinks average around 200 milligrams,” Janeiro says. “The FDA has cited 400 milligrams as a generally safe amount of caffeine for most healthy adults, but if you're drinking multiple energy drinks a day, plus other caffeinated beverages like coffee, black tea, soda, and more, you can easily consume over 400 milligrams.”

Total calories is another line item to look for on a nutrition facts label. Some energy drinks pack more than 200 calories per can—far more than you’d get from other caffeine boosts like coffee or tea. If you want to keep calories low, consider a beverage with 50 calories or less, such as Monster Energy Lo-Carb (30 calories) or Red Bull Sugar-Free (10 calories). And be sure to keep portion control in check by drinking just one at a time.

Healthy Alternatives to Energy Drinks

Energy drinks aren’t the only way to get a burst of energy. In fact, plenty of other options—including foods, drinks, and lifestyle choices—can give you extra oomph without the crash. For a dose of energy from caffeine, consider these foods and drinks: 

• Coffee
• Green tea
• Dark chocolate
• Yerba mate

Or, to elevate your blood sugar steadily, reach for foods with complex carbs. These include:

• Fruits like berries, apples, and citrus 
• Whole grains like brown rice, quinoa, whole wheat pasta, or oats
• Fiber-rich vegetables like sweet potatoes, broccoli, and carrots
• Beans and legumes

Got a little time? Try elevating your energy with a quick aerobic activity like jumping jacks, toe touches, or a walk around the block. And, of course, there’s always extra sleep to restore vitality. If you can squeeze in a power nap mid-day, you'll feel refreshed, with no sugar or caffeine required.