Energy Drinks and Stimulant Supplements Appear Disproportionately in Serious Heart Event Reports
Caffeinated energy drinks and stimulant supplements showed up far more often than comparison products in U.S. FDA adverse-event reports tied to serious cardiovascular outcomes, including cardiac arrest, heart attack and ventricular arrhythmias. The signal was strongest in adults ages 18 to 34, a group usually viewed as low risk for acute coronary disease and malignant rhythm disturbances.
The finding is preliminary, but it lands in a clinically uncomfortable place: products sold as routine pick-me-ups may be exposing younger people to stimulant loads that can exceed what the cardiovascular system tolerates, especially when use is repeated or combined with exercise, alcohol or other drugs.
A Safety Database Review Pointed to a Strong Reporting Signal
Investigators reviewed 28,345 adverse-event reports submitted to an FDA safety database from 2017 through 2025. Of those reports, 854 involved caffeine- or stimulant-containing energy drinks or dietary supplements, while 27,491 involved products without caffeine or other stimulants, including soft drinks, meal replacement shakes, protein bars, smoothies and vitamins.
The products were grouped by ingredient rather than by brand. The caffeine and stimulant category included caffeine itself, methylxanthines such as theobromine, guarana, yerba mate and green tea or coffee extracts, as well as sympathomimetics including synephrine, yohimbine, ephedra, DMAA and higenamine.
This was not a prospective trial and not a direct incidence study. It was a comparison of voluntary reports, which means the analysis can identify disproportionality, not causation. Even so, the contrast between stimulant-containing products and other consumer products was large enough to raise concern.
Cardiac Arrest and Myocardial Infarction Were Reported Much More Often
Cardiac arrest was reported about 11 times more often in connection with caffeine- and stimulant-containing products than with products without those ingredients. Reports involving energy drinks and supplements were about 4.5 times more likely to include heart attacks and four times more likely to include ventricular arrhythmias or heart palpitations.
Other cardiovascular complaints followed the same pattern. Elevated heart rate appeared nearly three times more often, chest pain appeared 2.71 times more often and fainting appeared about twice as often in reports tied to these stimulant products.
These are not trivial symptoms in a young person. Palpitations, chest pain and syncope can represent benign caffeine sensitivity, but they can also be the first warning signs of atrial or ventricular instability, ischemia or an underlying structural or inherited condition that has not yet been diagnosed.
The Young Adult Signal Raises Bedside Questions
About 45% of the reports linking caffeine- and stimulant-containing products to cardiovascular events involved adults ages 18 to 34. Similar patterns appeared in reports from men and women.
That age distribution matters because it shifts the clinical frame. In younger adults, chest pain and fainting are often triaged through a low-risk lens, yet stimulant exposure can move a patient into a much more dangerous physiologic state by raising sympathetic tone, increasing heart rate and blood pressure, and potentially lowering the threshold for ischemia or rhythm instability.
The mechanism is plausible. Very high caffeine doses and other stimulants can intensify adrenergic drive, increase myocardial oxygen demand and destabilize electrical conduction. In susceptible people, that can translate into palpitations, ventricular arrhythmias or acute coronary symptoms. In others, the exposure may simply unmask a condition that was already present but silent.
Daily Use Can Push Intake Beyond a Safe Threshold
A 2026 American Heart Association scientific statement says up to 400 mg of caffeine per day is generally safe for most adults. That amount is roughly equivalent to up to five 8-ounce cups of regular black coffee.
Energy drinks and pre-workout products can carry far higher concentrations than brewed coffee. Some energy drinks contain as much as three times more caffeine per fluid ounce than coffee, and some pre-workout supplements contain more than 12 times as much caffeine per fluid ounce. Repeated use across the day can push intake well beyond the range most adults think they are consuming.
The regulatory context also matters. Energy drinks and stimulant supplements are regulated as foods or dietary supplements rather than medications, so they do not undergo the same premarket safety testing required for drugs. Products with similar stimulant burdens can therefore reach the market without the kind of systematic cardiovascular review that would accompany a new prescription therapy.
What Clinicians Should Ask Young Patients
The abstract’s practical message is straightforward: younger patients with palpitations, chest pain or fainting should be asked directly about energy drinks, pre-workout products and other stimulant supplements. The question belongs in the medication history, not as an afterthought.
Sai Samayamanthula, the study author and a fourth-year medical student at the University of Virginia School of Medicine in Charlottesville, Virginia, said many healthy people probably face little risk when these products are consumed occasionally. Regular use is a different matter, especially when the cumulative caffeine burden can quickly exceed recommended limits.
Gregory M. Marcus, MD, MAS, FAHA, who was not involved in the study, said the findings raise concern that very high caffeine products may harm the cardiovascular system. He also emphasized a key scientific boundary: the analysis does not prove causation, because other factors could have influenced the reporting pattern.
Voluntary Reports Can Signal Harm Without Proving It
The study’s limitations are substantial and important. It relied on voluntarily reported events, so the database cannot show how many people consumed these products without incident, how many events went unreported, or whether the exposed group differed in other meaningful ways from the comparison group.
Young adults may use these products more often, may combine them with alcohol or drugs, or may consume them before intense exercise. Any of those behaviors could amplify cardiovascular stress and confound the association. An undiagnosed heart condition could also be part of the explanation in some cases, especially when the first presentation is a serious rhythm disturbance or sudden collapse.
Even with those limits, the pattern is difficult to ignore. A disproportionate share of serious heart event reports involved products that are widely marketed as ordinary lifestyle items rather than potent stimulants. For clinicians, the immediate consequence is a lower threshold to ask about these products when a young person presents with palpitations, chest pain or syncope. For regulators and researchers, the study argues for better safety surveillance and more rigorous prospective work to clarify which ingredients, doses and use patterns carry the highest cardiovascular risk.