Energy drinks are beverages that often contain high levels of caffeine and other stimulants. Previous research has linked energy drink consumption, particularly excessive intake, with various potential health risks.
While moderate caffeine intake may offer health benefits, excessive energy drink consumption has been linked to potential cardiovascular risks, including arrhythmias, tachycardia, and hypertension, particularly among young adults. Although there is currently no federal age limit for purchasing energy drinks in the U.S., there are proposals to restrict sales to minors.
Now, preliminary research presented at the American Heart Association (AHA) Scientific Sessions 2026 suggests that energy drinks and stimulant supplements may be associated with an increased likelihood of reports of serious heart-related events, particularly among young adults.
The findings are notable because cardiovascular events are generally less common among younger adults than older people, and almost half of the reports linking stimulant-containing products to cardiovascular events involved adults between the ages of 18 and 34.
However, the researchers emphasize that the findings demonstrate an association rather than a cause-and-effect relationship. The study also relies on voluntary reports of adverse events, meaning it cannot establish how frequently these events occur among people who consume energy drinks or supplements.
Additionally, it is important to note that these are preliminary findings and, as such, are not yet peer-reviewed.
For the study, researchers analyzed 28,345 reports of potential adverse events recorded in a U.S. Food and Drug Administration (FDA) safety database between 2017 and 2025.
Of these reports, 854 involved energy drinks or dietary supplements containing caffeine or other stimulants. The researchers compared these reports with 27,491 reports involving products without these ingredients, including soft drinks, protein bars, meal replacement shakes, smoothies, and vitamins. The analysis revealed several differences in the frequency of reported cardiovascular events.
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Compared with reports involving products without caffeine or other stimulants, reports involving stimulant-containing products were:
Importantly, these figures represent differences in the frequency of events reported to the FDA, rather than differences in the actual risk of experiencing a cardiovascular event. The study did not establish how many people consumed these products without experiencing adverse effects.
“These findings are concerning, but they are not entirely surprising,” Cheng-Han Chen, MD, board certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, who was not involved in the study, told Medical News Today.
“We know that energy drinks can have significant effects on the cardiovascular system, primarily because of their stimulant properties. Caffeine can increase blood pressure and heart rate, while other ingredients, such as guarana and taurine, may further contribute to cardiovascular stimulation and increased stress hormone levels.”
— Cheng-Han Chen, MD
“What is particularly concerning is the potential for these products to trigger serious complications, including abnormal heart rhythms, especially in people with underlying cardiovascular conditions,” continued Chen.
While occasional energy drink consumption is not likely to result in long-term consequences for most healthy individuals, frequent or excessive consumption can potentially increase the risk of hypertension and cardiac arrhythmias,” he added.
Caffeine is a stimulant that acts on the central nervous system, helping people feel more alert and less tired. However, it can also affect cardiovascular function, particularly at higher doses or in people who are sensitive to its effects.
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Research suggests that consuming up to 400 milligrams (mg) of caffeine per day is generally considered safe for most healthy adults. This is equivalent to roughly four to five 8-ounce cups of regular brewed coffee, although caffeine content varies by preparation.
Energy drinks and pre-workout supplements can contain substantially more caffeine per fluid ounce than brewed coffee. Some products also contain additional stimulant ingredients, which may contribute to their overall physiological effects.
The combination of caffeine and other stimulants may be relevant when assessing potential cardiovascular effects. However, the current study did not establish which ingredients, doses, or combinations were responsible for the patterns observed in the reports.
Energy drinks and stimulant supplements are also regulated differently from medications in the U.S. Because they are generally regulated as foods or dietary supplements, they do not undergo the same premarket approval and safety testing requirements as prescription medications.
“Caffeine stimulates the cardiovascular system, primarily by increasing sympathetic nervous system activity. This can cause the heart to beat faster, raise blood pressure, and increase the workload on the heart. Energy drinks may contain additional stimulants, such as guarana and taurine, which can further increase blood pressure and stress hormone levels,” Chen explained to MNT.
“With excessive consumption, these effects can become more pronounced and potentially interfere with the heart’s normal electrical activity, increasing the risk of abnormal heart rhythms. People with underlying cardiovascular conditions, particularly hypertension or a predisposition to arrhythmias, may be especially vulnerable to these effects.”
— Cheng-Han Chen, MD
The researchers found that adults ages 18 to 34 accounted for approximately 45% of reports linking caffeine- and stimulant-containing products to cardiovascular events. The study did not determine why this age group was so prominently represented. However, the researchers suggest some possible explanations.
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Younger adults may consume energy drinks and stimulant supplements more frequently, particularly to improve alertness, support exercise, or manage fatigue. The timing and circumstances of consumption could also be relevant, including taking stimulant products before intense physical activity or combining them with alcohol or other substances.
They also note that many people may underestimate the potential risks and exceed recommended daily caffeine limits without realizing it, given how widely available energy drinks and supplements are. The findings suggest that healthcare professionals may benefit from asking younger people who experience palpitations, chest pain, or fainting about their use of energy drinks and stimulant supplements.
“There is growing concern about the cardiovascular effects of energy drinks and stimulant-containing supplements, particularly among younger adults. One challenge is that younger individuals may not recognize that these products can have significant effects on their heart and blood pressure, especially when consumed frequently or in combination with other caffeinated products.”
— Cheng-Han Chen, MD
The researchers also suggest that some individuals may have underlying heart conditions that have not yet been diagnosed.
“As a cardiologist, I am particularly concerned about people who may have underlying cardiovascular conditions that have not yet been diagnosed. Excessive stimulant intake can potentially trigger symptoms such as palpitations, chest discomfort, and lightheadedness. In susceptible individuals, it may also increase the risk of more serious complications, including abnormal heart rhythms,” Chen explained.
However, it is also important to consider that the proportion of reports involving young adults does not necessarily mean that young adults have a higher risk of cardiovascular complications than other age groups. Differences in consumption habits, reporting behavior, and the number of people using these products could influence the results.
While the findings suggest a link, the study cannot establish that energy drinks or stimulant supplements directly cause cardiac arrest, heart attacks, or other cardiovascular events.
Although the FDA reports can help identify potential safety signals, they do not provide a complete picture of how often adverse events occur.
Additionally, the analysis cannot account for other factors that may have contributed to the reported events, including preexisting medical conditions, other medications or substances, exercise, and the amount of caffeine consumption.
Further research is necessary to determine whether stimulant-containing products are directly responsible for cardiovascular complications and to identify which ingredients, doses, and patterns of consumption may pose the greatest risks.
The findings highlight the importance of understanding how much caffeine and other stimulants people consume, particularly when using multiple products throughout the day.
Caffeine may be present in coffee, tea, energy drinks, pre-workout supplements, and other dietary products. Consumers who combine these products may find it difficult to estimate their total daily intake.
Checking product labels and considering caffeine intake from all sources may help people avoid unintentionally consuming excessive amounts. It is also important to remember that the amount of caffeine in a product does not necessarily reflect the effects of its other stimulant ingredients.
“Some warning signs of excessive stimulant intake include heart palpitations, chest pain, and lightheadedness. Depending on the severity of these symptoms, medical attention may be necessary,” Chen highlighted.
“For most healthy adults, we generally recommend limiting total daily caffeine intake to no more than 400 milligrams. However, individual tolerance varies, and people with underlying cardiovascular conditions, particularly high blood pressure, or abnormal heart rhythms, may need to limit or avoid caffeine altogether.”
— Cheng-Han Chen, MD
Chen also pointed out that energy drinks may have varying caffeine contents and serving sizes, which affect the amount consumed.
“Depending on the product, a single can may contain anywhere from 80 to 300 milligrams of caffeine. This means that consuming even one or two energy drinks can put someone close to or above the recommended daily limit, particularly when combined with coffee, tea, or other caffeinated supplements,” he said.
“I encourage people to read product labels carefully and be aware of their total daily caffeine consumption. It is also important to remember that caffeine is not necessarily the only concern, as many energy drinks contain additional stimulants that can further increase blood pressure and cardiovascular stress,” Chen said.
“I particularly recommend that people with underlying cardiovascular conditions avoid energy drinks,” he concluded.
It is advisable for people who experience symptoms such as chest pain, fainting, or a rapid or irregular heartbeat to seek appropriate medical evaluation.
Although the findings raise concerns about the possible risks associated with these products, larger and more rigorous studies are necessary to establish the direct effect of caffeine and other stimulants on heart health.
