What Are Energy Drinks?
They're actually a popular dietary supplement. Energy drinks can contain many types of active ingredients. Your local store likely has shelves full of these drinks.
Different drink brands claim to boost your mental ability or physical energy. And some have very high caffeine levels, causing life-threatening symptoms. Some energy drinks can have safety problems, too.
"When it comes to these popular drinks, it’s really buyer beware," says Marc-Alain Babi, MD, chief of neurocritical care at Cleveland Clinic Florida Martin Health in Stuart, FL.
Energy drink brands also claim to supercharge your daily activity. Some drink labels promote better work focus or afternoon gym workouts. Energy drinks are a big, booming business. In fact, people spent $21 billion in 2024 on them. That's 10 billion more than in 2017.
The FDA doesn't approve energy drinks. That "means a brand can add pretty much any ingredient they want to the drink," says Babi. "We’re also seeing more and more reports of patients who have experienced serious side effects."
The problems can include a "stroke or even liver or kidney failure," he says. So before you take a sip of an energy drink, here are a few things to know.
Types of Energy Drinks
Energy drinks often have many supplements added to them. Some energy drink brands are stronger than others. There are two main types of energy drinks:
Classic energy drinks. These are normal-sized drinks in cans or 16-ounce bottles.
Energy shots. They're a stronger type of energy drink. These smaller cans only hold 2 to 2.5 ounces of liquid.
"It is usually all the same ingredients, in a much more concentrated form," says Julie Stefanski, RDN, LDN, a nutritionist specializing in sports nutrition and fitness and a fellow of the Academy of Nutrition and Dietetics in York, PA.
Most Common Energy Drink Ingredients
The leading ingredient in any energy drink is usually caffeine, says Stefanski. Energy drinks typically don't have alcohol. Most of them contain herbs, caffeine, and other substances. And many energy drink brands claim to be supplements. These have vitamins or herbs.
If you look closer at your energy drink label, you may find:
Caffeine. A 16-ounce energy drink can have 70 to 240 milligrams (mg). But an energy shot can have 100 to 200 mg of caffeine.
"Caffeine is one of the most researched stimulants we have," says Stefanski. "And we know it can help with both alertness and with athletic performance.”
But you can get too much of a good thing. The FDA suggests less than 400 mg of caffeine a day for adults. That's about two to three 12-ounce cups of coffee.
Sugar. Sugar is a main ingredient in these drinks, says Stefanski. It provides energy but can also cause problems, especially if you have medical conditions like prediabetes, she says.
Some dietary guidelines suggest sugar be less than 10% of your daily calories. But some energy drinks can have 12 teaspoons of added sugar. That's 200 calories. So one energy drink is an entire day's worth of sugar for a 2,000-calorie diet.
Taurine. Taurine is an amino acid naturally found in your body. It's also in foods such as meat and seafood. "It helps your body metabolize energy," says Babi. The cells in your body uses (metabolizes) it for energy.
But some research shows taurine doesn't boost physical or mental actions. "In large doses, we also worry that it can impact your heart, as well as your neurological system," he says.
Taurine helps your body make bile acid and balance fluids, salts, and minerals. Drinking too much can dehydrate you. It may also lead to feeling nervous or prevent sleep.
Guarana. Guarana comes from the seeds of the plant Paullinia cupana. The seed extract has caffeine and other active compounds.
"It works in your body similarly to caffeine," says Babi. "The concern is that if two [compounds] are combined, they could cause side effects." These can include the jitters, a fast heart rate (palpitations), or anxiety. And guarana could impact your health, he says.
It's unclear if guarana can lead to liver problems. Some studies found guarana safe. Studies showing liver problems mixed two or more ingredients. This makes it hard to know which compound may cause damage.
Other energy drink ingredients.L-carnitine is commonly added to energy drinks. This molecule helps your body use fat as energy. Usually, your body makes enough carnitine. But some medical conditions or medications can lower your levels.
Energy drinks claim this molecule boosts physical performance. But the claims aren't backed up by research, Babi says. High doses of L-carnitine may cause problems in the gut, like diarrhea. It can also interact with some medications. Talk to your doctor before using energy drinks with L-carnitine if you take:
- Thyroid hormone for underactive thyroid (hypothyroidism)
- Valproic acid (Depakote) for seizures
- Blood thinners for clotting problems
B vitamins are added to energy drinks as well. They help turn your food into energy. But you get most B vitamins from your food, says Stefanski. Unless you're pregnant, or unless you don't eat animal products or B12-fortified foods, you'll likely not need a supplement. Talk to your doctor if you think you're low.
"Since B vitamins aren’t stored in your body, you’ll likely just pee out any excess," she said. But at very high doses, for long periods, some can cause problems. For example, very high doses of vitamin B6 can damage your nerves.
Effects of Energy Drinks
It’s true, you may feel more energy after drinking an energy drink. That’s most likely from the sugar and caffeine, says Stefanski. But there could be a lot of side effects, too. You may feel wired. And some ingredients can trigger symptoms of medical conditions.
Energy drink side effects
A fast heartbeat and feeling hyper are common symptoms, says Stefanski. After an energy drink, you may:
- Feel nervous
- Be unable to sleep (insomnia)
- Get cranky
- Feel head pain (headache)
- Have tremors
- Have an upset stomach, nausea, or diarrhea
Some medical conditions can raise your risk of certain symptoms. "If you have a history of seizures or epilepsy, any stimulant can cause a breakthrough seizure," says Babi. "And if you have high blood pressure, you may be more likely to experience a stroke."
And rarely, energy drinks may cause inflammation of the pancreas (pancreatitis) in adults. But the exact triggers are unclear.
Why do energy drinks make me tired?
Some energy drinks contain high sugar and caffeine levels. Once your body digests these, the effects wear off. You’re likely to crash. It can mean your blood sugar drops and your brain activity lowers. You may feel sleepy, says Stefanski.
The caffeine can dehydrate you, too. This can also make you feel sluggish. But drinking energy drinks long-term can make you feel tired.
"Ironically, they can affect your sleep, as well," says Stefanski. "So it’s harder to both stay and fall asleep."
The next day, you may feel tired or groggy. This can make you more likely to drink another one. The hope is the energy drink can power you through the day.
"But it becomes a vicious cycle," says Stefanski. Over time, the same amount of caffeine can stop working. You may not feel as much energy. It's called caffeine tolerance. So you may feel like you need more caffeine to stay awake.
But this isn't the best practice. And it can lead to more health problems. Talk to your doctor if you're having problems staying awake or sleeping at night.
Are Energy Drinks Bad for You?
Some energy drinks combine many ingredients. They contain high levels of caffeine, sugar, or herbs. These drinks aren't regulated by the FDA, either.
Energy drinks may be dangerous for some people, says Babi. Here’s a closer look as to why.
Are energy drinks bad for your heart?
Adding high amounts of caffeine and other stimulants can cause problems. Stimulants refer to compounds raise your alertness. These types of drinks can raise your heart rate or blood pressure, too. And your heart can beat faster, or irregularly, says Babi.
"Even if you’re young and otherwise healthy, it can push your heart rate into dangerously high levels," he says.
You may have too much caffeine if you:
- Get jittery
- Can't sleep (insomnia)
- Have a faster heart rate
- Feel anxious
- Have a headache
- Get nausea or an upset stomach
- Get higher blood pressure
There have been a few reports of a sudden heart attack (cardiac arrest) from energy drinks. "These may have been people who appeared healthy, but had an underlying heart condition they weren’t aware of," says Babi.
Long-term effects of energy drinks
The long-term problems from energy drinks aren’t clear. That's because these drinks haven’t been well-studied.
"Since every energy drink is different, it’s also hard to generalize," says Stefanski. "They each may have their own long-term health effects."
The problems can depend on the type of energy drink. And your health matters, too. Other factors include your medications and the mix of ingredients.
"But it’s reasonable to assume that if you consume them frequently, there will be health effects from your heart rate and blood pressure being elevated for extended periods of time," says Stefanski.
Talk to your doctor about drinking energy drinks long-term. They can help you sort out compounds that may interact.
Your doctor can help you prevent serious side effects like heart attacks, strokes, seizures, liver problems, or kidney damage. These complications can have a lasting impact on your health, says Babi.
Are there healthy energy drinks?
An occasional energy drink is likely not harmful. And you'll probably get energy and better focus for a short time. But there aren't many rules about how they're made.
"There’s no industry standard for the term 'healthy,'" says Stefanski. “An energy drink manufacturer can tout that their drink is healthier, but there’s no way to know for sure since they’re not regulated by the FDA."
So an energy drink brand can claim it's healthier. But there may not be scientific evidence that it's true. So watch out for any claim made on energy drinks. These aren't verified by the FDA or independent studies.
For example, some of the drinks claim to avoid added sugar. "But they may be loaded with caffeine and other stimulants to give you a boost of energy," Stefanski says.
Are Energy Drinks Safe?
Energy drinks are a kind of dietary supplement. Companies don't have to make them meet the same safety standards as medications.
But they do have to follow the FDA rule called GRAS. That means the ingredients in your energy drink must be "generally recognized as safe."
And highly pure forms of caffeine can cause life-threatening symptoms. "It’s up to [you] to read labels carefully, and to connect the dots," says Stefanski.
What is the healthiest energy drink?
The healthiest energy drink isn’t one at all. If you need a quick boost, Stefanski says, grab a cup of coffee.
You can also try to drink black or green tea. Another energy-boosting option is to work out for an hour or more.
And if you're in very hot conditions, try an electrolyte drink or oral rehydration solution (ORS). These drinks help replace electrolytes that sweat away when working out.
Are energy drinks safe for kids?
About 30 to 50 out of every 100 teens say they drink energy drinks. But the American Academy of Pediatrics suggests only adults drink them.
"Their brains and bodies are rapidly developing, so they’re more susceptible to side effects than adults," says Babi.
Between 2022 and 2023, the American Poison Center reported about a 24% increase in energy drink calls from children and teens under age 20. And the highest number calls were from kids ages 6 to 12.
The American Academy of Pediatrics, American Heart Association, and Academy of Nutrition and Dietetics suggest kids and teens avoid drinks with:
- Stimulants like caffeine
- Added sugars
Water and milk are better choices for children and teens. After a workout, choose a healthy recovery drink. Try low-fat chocolate milk after practice for fluid and hydration.
Milk can provide the nutrients and vitamins you need to recover. Talk to your doctor or nutritionist about ideas for your child's diet.
Do energy drinks interact with medicine?
It depends on the drink contents. Type 2 diabetes and blood thinner medications don't work as well with higher caffeine levels.
If you take medication, talk to your doctor or pharmacist first. It's important to let them know what you're drinking, says Babi.
Mixing alcohol and energy drinks
There are many reasons not to mix alcohol and energy drinks. Energy drinks can hide the effects of alcohol. So you may drink more than usual. Or they can raise your risk of dehydration, too.
“When you mix a stimulant like caffeine with a certain nervous system depressant such as alcohol, it impacts your brain pathways in a way that causes you to distort reality,” says Babi.
This means you may not think through decisions (be more impulsive). You may be more likely to take risks, too. And caffeine doesn’t cancel the impact of alcohol on your body. If you add alcohol to an energy drink, you may raise your risk of:
- Binge drinking
- Unprotected sex
- Injury
- Drunken driving or riding with a drunk driver
And mixing alcohol and caffeine can make you urinate (pee). Peeing more often can dehydrate you. If this happens, drink plenty of water and other fluids.
Who shouldn’t drink energy drinks?
Ideally, everyone should skip energy drinks, says Babi. You may be at a higher risk of side effects. You should avoid energy drinks if you:
- Are a child or teen
- Are pregnant or trying to get pregnant
- Have a medical condition (like high blood pressure; heart, liver, or kidney problems; and more)
- Take regular medication
5 Energy Drink Alternatives
The physical or mental boost from energy drinks are short-lived, says Stefanski. For more long-lasting effects, consider one of these options:
- Water. One common reason for feeling tired is dehydration. Even mild dehydration can sap energy stores. You can feel sleepy, tired or less alert. Try adding some cucumber or fruit slices to your water for flavor.
- Black coffee. A cup of coffee can increase alertness. It also contains antioxidants that are good for your health, says Stefanski. You can safely drink about 400 mg of caffeine daily. That's the amount in about two to three cups a day. But if coffee leaves you a little too jittery, try to swap it with decaf. Or mix it with half-and-half. A cup of decaf still has a small amount of caffeine. And it may still raise your alertness better than other drinks.
- Green tea. It’s rich in caffeine, L-theanine, and epigallocatechin gallate (EGCG). These compounds may keep you alert. It’s a good option if you find black coffee leaves you too jittery. A cup of green tea has just under 40 mg of caffeine. That's only a third of what you'd get in a cup of java.
- Hydrating foods. Around 20% of our water intake comes from food. Cucumbers are a good option; they’re about 95% water. Other sources include tomatoes, melons, celery, peaches, zucchini, radishes, asparagus, and lettuce.
Foods with caffeine. There’s a reason you get an energy rush after you eat chocolate – it has cocoa. And cocoa has caffeine. But if you do use chocolate as a pick-me-up, keep it small. This helps keep the fat and calories down, says Stefanski.
An ounce of dark chocolate has about 24 mg of caffeine. But milk chocolate only has about 6 mg. Some brands of chewing gum also contain caffeine.
Takeaways
The popular boost of an energy drink isn't without health risks. These drinks can raise your heart rate, blood pressure, and cause other symptoms, like anxiety or trouble sleeping. While sipping on one occasionally may be fine, it’s best to limit their use. Other good alternatives are water, black coffee, green tea, and water-rich foods.
Energy Drink FAQs
What energy drink has the most caffeine?
It’s hard to know which energy drink brand has the most caffeine. Drink companies must list some ingredients on the label. But they don't have the same rules as medications. This means many companies don't tell you how much caffeine there is. Some have over 300 mg in 16 ounces.
How many energy drinks is too many?
It’s best not to drink more than one at a time, says Stefanski. That way, you can see how you feel. And you can watch for any side effects, too.
You can notice if you get jittery or have a faster heart rate. It’s best to only use energy drinks now ant then, if at all.
Can energy drinks cause you to die?
There have been a few cases of high caffeine levels in energy drinks triggering heart attacks that caused death. Although energy drinks don't directly cause you to die, some ingredients can trigger health conditions. High caffeine levels can raise your risk of a seizure or heart attack.
"Most of the time, these [cases] occur in seemingly healthy young adults," says Babi. "They [likely] have an undiagnosed heart condition."
Medical conditions can be hard to predict. So it's a good idea to avoid energy drinks entirely. Try other alternatives to energy drinks instead.
