The short answer: energy drinks may be hard on the heart, especially in large amounts, but the new research doesn’t prove they cause heart attacks. Research presented by the American Heart Association in November 2026 found cardiac arrest was reported about 11 times more often for caffeine and stimulant products than for similar products without them. For most healthy adults, an occasional can is probably low risk. The bigger concern is regular use that pushes you past 400 mg of caffeine a day.
The findings are preliminary and haven’t been peer reviewed yet. They still got wide coverage, because the group most often involved was young adults who aren’t usually thought of as being at risk.
What did the new study find?
Researchers looked at 28,345 reports sent to an FDA safety database from 2017 to 2025. Of those, 854 involved energy drinks or stimulant supplements. They compared those with 27,491 reports about products without stimulants, such as soft drinks, protein bars, smoothies and vitamins.
| Reported problem | How much more often with stimulant products |
|---|---|
| Cardiac arrest | About 11 times |
| Heart attack | About 4.5 times |
| Dangerous heart rhythms or palpitations | About 4 times |
| Fast heart rate | Nearly 3 times |
| Chest pain | 2.71 times |
| Fainting | About 2 times |
About 45% of the heart reports involved adults aged 18 to 34. The pattern was similar in men and women.
Does this prove energy drinks cause heart attacks?
No. The American Heart Association says plainly that the results can’t prove these products directly caused any heart problem. Here’s why the numbers need care:
- The reports are voluntary. Consumers, doctors and manufacturers choose whether to send them.
- There’s no count of everyone else. Nobody knows how many people drank these products with no problem, so this can’t tell you your personal risk.
- “11 times” describes reports, not people. It doesn’t mean an energy drink makes you 11 times more likely to have a cardiac arrest.
- Other things could explain it. The researchers pointed to drinking them before hard exercise, mixing them with alcohol or drugs, and heart conditions nobody knew about.
The study also grouped products by ingredient, not brand, so it says nothing about any single can on the shelf.
How much caffeine is in an energy drink?
It varies more than most people expect. The American Heart Association says some energy drinks have up to 3 times more caffeine per ounce than brewed coffee, and some pre-workout supplements have more than 12 times as much. These are typical published amounts, but recipes change, so check your own label.
| Drink | Size | Caffeine |
|---|---|---|
| Black coffee | 8 oz | About 80 mg |
| Red Bull | 8.4 oz | About 80 mg |
| Monster | 16 oz | About 160 mg |
| Celsius | 12 oz | About 200 mg |
| Bang | 16 oz | About 300 mg |
The coffee figure comes from the heart association’s comparison of 400 mg to five 8-ounce cups. Real coffee varies a lot with the beans and the brew.
How much caffeine is too much?
For most adults, 400 mg a day. The FDA says that amount isn’t generally linked to negative effects, and a 2026 American Heart Association statement says it’s generally safe for most adults. Two strong cans can get you there before you count any coffee, tea or soda.
That limit doesn’t suit everyone. The FDA says sensitivity and the speed you clear caffeine both vary a lot, and that some conditions and medications can make its effects stronger. Doctors advise against energy drinks for children and teens. If you’re pregnant, trying to get pregnant or breastfeeding, ask your provider how much caffeine is right for you.
Very large doses are a different danger. The FDA estimates that toxic effects like seizures can appear after about 1,200 mg taken quickly. That’s why pure and highly concentrated caffeine powders and liquids are so risky.
Are energy drinks worse than coffee?
They’re not the same thing, even when the caffeine matches. The new study covered ingredients such as guarana, yohimbine and synephrine along with caffeine. Because the FDA treats these products as foods or supplements, they don’t go through the safety testing required for medicines before they’re sold.
Moderate coffee, meanwhile, has been linked with lower rates of heart disease and stroke in observational studies. That doesn’t prove coffee protects you, but it’s a very different record.
How can you cut your risk?
- Read the caffeine on the can. If there are two servings in it, double the number.
- Count your whole day. Add coffee, tea, soda, pre-workout and any fat burner.
- Don’t pair it with alcohol or hard exercise. Researchers flagged both as possible reasons for the pattern.
- Be wary of long ingredient lists. Yohimbine and synephrine were among the stimulants in this study.
- If you need one every day, ask why. Daily exhaustion usually has a cause, and these are the most common reasons you’re always tired.
If you already have high blood pressure, ask your doctor about caffeine, and read our guide on how to lower blood pressure.
When should you get help?
Call 911 if you have chest pain, you faint, or your heart is racing and you feel short of breath, confused or close to passing out. Don’t wait to see if it settles.
See a doctor soon about palpitations that keep coming back, even if you feel fine now. Tell them exactly what you drink and how much. The study’s author urged doctors to ask younger patients with these symptoms about energy drinks, so it’s useful information for them.
A simple new habit
The Banana Book
A 7-day banana habit plan plus 60 simple recipes, with protein, fiber and calories listed on each one. Not for medically prescribed diets. Only $4.99.
Quick questions
Can one energy drink cause a heart attack?
It’s unlikely for most healthy adults, and the new research can’t show that it does. The study author said the risk is probably small for healthy people who drink them occasionally. If you get chest pain after one, treat it as an emergency.
How many energy drinks a day is safe?
There’s no official number of cans. The useful limit is 400 mg of caffeine a day for most adults, from all sources. Depending on the brand, that could be just over one can or five small ones.
Are sugar-free energy drinks better for your heart?
Sugar-free drinks avoid the sugar, but they still carry the caffeine and other stimulants. The new study looked at those ingredients, so going sugar-free doesn’t change that concern.
How long does caffeine stay in your body?
It varies from person to person. The FDA says people differ widely in how fast they clear caffeine, and some conditions and medications change that. If an afternoon can keeps you awake at night, move it earlier or drop it.
Should I stop drinking energy drinks?
If you drink them often, go past 400 mg of caffeine a day, or have a heart condition or high blood pressure, cutting back makes sense. Talk to your doctor if you’ve had palpitations, chest pain or fainting.
This article is general information, not medical advice. If you have a heart condition, take medication or have had symptoms, talk with your doctor.
Sources
- American Heart Association: Energy drinks, stimulant products linked to cardiac arrest, heart attack in young adults (Nov 2, 2026)
- FDA: Spilling the Beans, How Much Caffeine Is Too Much?
- Marcus GM et al. Caffeine and Cardiovascular Disease: A Scientific Statement From the American Heart Association. Circulation, 2026
- The Takeout: Popular energy drinks ranked by caffeine content (brand amounts; check your label)