Specific ingredients vary by manufacturer and brand.

However, almost all popular energy drinks like Monster, Red Bull and Rockstar rely on three primary ingredients. Two of them can cause major health issues when you consume more than you should.

Caffeine

Almost all of us consume caffeine every day, whether it’s in energy drinks, coffee, tea, soda, or chocolate (yes, there’s caffeine in chocolate). Energy drinks rely on caffeine because it’s a central nervous system stimulant that also blocks the process that causes drowsiness. 

The stimulant’s effects on your body depend largely on the amount of caffeine you consume. That, in turn, depends on much is in the food or drink you’re consuming, and how much of it you eat or drink.

The average cup of coffee contains about 90 milligrams of caffeine. Soda has about half that amount; tea and chocolate have much less. Energy drinks, though, generally contain anywhere between 110mg (Red Bull) and 160mg (Monster and Rockstar). Some like Bang contain as much as 300mg of caffeine.

Those high levels of caffeine can add up quickly, and that’s when problems arise. The U.S. Food and Drug Administration (FDA) says that most healthy adults can consume up to 400 milligrams of caffeine per day. Some people, naturally, have less tolerance than others.

A limit of 400mg of caffeine lets you have about 4-5 cups of coffee or 9-10 sodas per day. But just three Monsters or Rockstars puts you into the FDA’s “danger zone” – as does more than one supercharged energy drink like Bang.

And that’s when negative health effects can hit. We’ll discuss those effects in a bit.

Sugar

If you don’t reach for an energy drink when you need a pick-me-up, you may very well reach for a candy bar.

That’s the same reason most manufacturers put a ton of sugar into their energy drinks. The sweet stuff seemingly provides a quick energy boost within just a few minutes.

We hate to break the news, but a sugar high doesn’t really mean that your body has any additional energy to use. It just feels that way.

As the body processes sugar, it releases additional amounts of the “feel-good” hormone dopamine and the “happiness” hormone serotonin – meaning that you feel better and may think you have more energy.

The feeling doesn’t last long, though. After 30-60 minutes of a sugar high, you experience a sugar crash and feel less energetic. The news gets worse; the process required to digest sugar decreases the body’s ability to generate energy.

So the sugar in an energy drink doesn’t increase energy levels; it just makes you feel more upbeat for a little while. You’re better off drinking a brand (like Super Energy) that uses natural sweeteners like stevia and monk fruit extract instead of sugar.

Even worse, consuming high amounts of sugar can cause or contribute to a number of negative health effects. We’ll elaborate shortly.

Other Common Energy Drink Ingredients

Most brands of energy drinks (and many sports drinks) are likely to contain several other ingredients.

• B Vitamins: These vitamins don’t provide an energy boost on their own; they just help the body convert food to energy. However, they can help people who don’t get enough B vitamins in their normal diet.
• Taurine: This amino acid has been shown to boost endurance, physical performance, and cognitive performance, particularly when combined with caffeine.
• Guarana: Guarana is another source of caffeine, and contains other natural stimulants.
• Ginseng: This is a medicinal herb that’s said to help boost the body’s energy levels.
• L-Carnitine: This amino acid has been shown to increase energy, but the amount in energy drinks probably won’t help much.
• Glucuronolactone: This natural compound is believed to help prevent the body from breaking down stored glucose, but there’s no proof that the amount in energy drinks does any good.

Now for the important question.

We started with the important one: energy drinks give you about an hour of extra energy because of their caffeine content. They may also taste good and fill you up for a little while.

Unfortunately, energy drinks may also cause harmful effects. Once again, we’ll look at them by ingredient.

Effects of Caffeine in Energy Drinks

The high caffeine content in energy drinks can certainly wake you up.

It increases energy metabolism and slows down blood flow in the brain while stimulating the release of dopamine, the “fight or flight” hormone adrenaline, and the stress hormone cortisol. Caffeine also blocks the effects of the neurotransmitter adenosine, which would ordinarily make you feel more tired.

All of those effects tend to make you alert, vigilant, and happier for a while. And moderate consumption of the caffeine in energy drinks doesn’t normally have serious side effects.

Here’s the bad news.

When you consume “too much” caffeine – the government’s 400mg per day is the common benchmark, but some people can’t tolerate that much – you’re likely to suffer the consequences. Most devoted coffee drinkers are aware of the unpleasant “jitters” that tell you when you’ve overdone the caffeine.

That’s not the worst of it. High levels of caffeine consumption can cause an increase in heart rate, heart palpitations, abnormal heart rhythms, anxiety and high blood pressure. Caffeine can also increase the production of stomach acid, causing heartburn.

Those issues may last as long as six hours after having a couple of energy drinks, but they aren’t usually reasons to head to your hospital’s emergency department. If you have pre-existing cardiovascular or stomach issues, however, the health risks are much greater.

Regularly-high levels of energy drink consumption can also lead to caffeine addiction. When you don’t get your daily fix, you’re likely to suffer side effects of caffeine withdrawal like headaches, depression, or difficulty focusing.

Effects of Sugar in Energy Drinks

There’s a lot of sugar in most energy drinks, somewhere around 30 grams per eight ounces. The majority of these drinks are sold in larger cans than that, which means even more sugar. Using an easier-to-understand measurement, there are 14 teaspoons of sugar in a 16-ounce can of Monster, and 20+ teaspoons in some Rockstar products.

As you might guess, that’s more sugar than experts recommend consuming in an entire day. The American Heart Association says women should have no more than six teaspoons of added sugar daily, and men should stay below nine teaspoons.

What happens when you dramatically overdo the sugar, as you would when drinking a few of these sugar-loaded energy drinks each day? You have an increased risk of experiencing serious health issues.

• Weight gain and obesity: You already know that sugar can contribute to weight gain, of course, but there’s one other factor to consider. The fructose in most energy drinks makes your brain crave more sugar and more food in general.
• Type 2 diabetes: Overconsumption of sugar has been found to be the number one risk factor for diabetes. It can also contribute to the development of metabolic syndrome.
• Cardiovascular disease: Diets high in added sugar have been shown to cause or contribute to higher blood sugar levels, high blood pressure, inflammation, and as we’ve just mentioned, obesity and diabetes. Those are all significant risk factors for heart disease.

Other health issues linked to high consumption of sugar include acne, cellular aging, liver and kidney disease, and even cancer. It can also contribute to mental health issues like depression.

Sales of energy drinks in the U.S. continue to soar. More than one-third of Americans aged 18-49 consume energy drinks, and the drinks are most popular among teenagers, college students and young adults.

The American Academy of Pediatrics (AAP) has done a large study on the use of energy drinks by children and adolescents. Like other healthcare professionals and organizations, they strongly recommend against energy drink consumption by people in those age groups.

The AAP cites a lower tolerance to caffeine, still-developing cardiovascular and neurological systems, and energy drinks’ high sugar content as strong arguments against the use of these drinks by kids and teens.

You’re past that age? Well, at least now you know the pros and cons.