Research highlights:
- In a review of more than 28,000 adverse reaction reports submitted to the FDA over eight years, from 2017 to 2025, caffeinated energy drinks and stimulant supplements were linked to serious heart disease far more often than other products.
- Products containing caffeine or other stimulants were associated with more cardiac arrests and heart attacks, particularly among adults aged 18 to 34, a group not generally considered to be at high risk of cardiovascular events.
- More studies are needed to understand the relationship between caffeinated products and cardiovascular disease, as well as systematic monitoring of the safety of these products, the researchers said.
- Note: The study presented in this press release is a research summary. Abstracts presented at American Heart Association scientific meetings are not peer-reviewed and results are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.
Embargoed until 4 a.m. CT/5 a.m. ET, Monday, November 2, 2026
DALLAS, November 2, 2026 — Caffeinated energy drinks and stimulant supplements appear disproportionately more often in FDA reports of serious cardiovascular events, including cardiac arrest and heart attacks, especially among adults ages 18 to 34, according to new independent preliminary research to be presented at the American Heart Association. Scientific sessions 2026. The meeting, to be held November 6-9 in Chicago, is a premier global exchange on the latest scientific advances, research and evidence-based clinical practice updates in cardiovascular science.
Sales of caffeinated energy drinks have more than doubled over the past decade, reaching more than $20 billion in 2024. Although research on energy drinks and other supplements containing stimulants is limited, available evidence indicates that high doses of caffeine are associated with cardiovascular damage. Healthcare professionals have also described cases of arrhythmias (irregular heart rhythms) or sudden cardiac death in people who consumed these products, many of whom were young adults with no known risk of heart disease.
According to a 2026 scientific statement from the American Heart Association on caffeine and cardiovascular disease, consuming up to 400 mg of caffeine per day (the equivalent of 5, 8-ounce cups of regular black caffeinated coffee) is generally safe for most adults. Compared to brewed coffee, some energy drinks contain up to 3 times more caffeine per fluid ounce, and some pre-workout supplements contain more than 12 times more caffeine per fluid ounce. Because the U.S. Federal Drug Administration (FDA) regulates energy drinks and stimulant supplements as foods or dietary supplements rather than as drugs, these products are not subject to the same pre-market safety testing required for drugs.
“These products are marketed as daily pick-me-ups and sold alongside soda and bottled water, so most people assume they carry no real risk,” said study author Sai Samayamanthula, a fourth-year medical student at the University of Virginia School of Medicine in Charlottesville, Virginia. “For many healthy people, if these products are consumed occasionally, the risk is probably low. However, people who regularly consume energy drinks or other supplements containing stimulants can quickly exceed the recommended daily limit of caffeine. So it is important that people know that there may be a risk of cardiovascular damage with these products.”
Researchers analyzed data from a government safety database to compare reports of adverse reactions linked to products containing caffeine and other stimulants versus FDA-regulated foods and dietary supplements such as soft drinks, meal replacements, protein bars, smoothies and vitamins. The data included reports from people aged 13 or older between 2017 and 2025.
What are the main conclusions of the study analysis?
- Cardiac arrest has been reported approximately 11 times more often in connection with products containing caffeine and stimulants compared to products not containing these 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 (abnormal rhythm in the lower pumping chambers of the heart) or heart palpitations.
- Similar trends existed between consumption of caffeinated energy drinks and stimulant supplements and reports of other heart problems, including elevated heart rate (nearly 3 times more often), chest pain (2.71 times more often), and fainting (about 2 times more often).
- About 45% of reports linking caffeinated products and stimulants to cardiovascular events involved adults aged 18 to 34.
- Similar trends were observed in reports involving both men and women.
“Our findings argue for more systematic safety monitoring of products containing caffeine and stimulants. Additionally, health care professionals should consider asking their younger patients who have palpitations, chest pain, or fainting whether they recently or regularly consume these products,” Samayamanthula said.
Researchers don’t really understand why the association between caffeine and stimulant products and cardiac events was so common among young adults. The pattern of reports among young adults may reflect the frequency with which they consume caffeinated products and stimulants; when and how people tend to consume them (for example, consuming them before strenuous exercise or mixing them with alcohol or drugs); and/or whether they may have undiagnosed heart disease.
“This study raises concerns that products containing very high amounts of caffeine may be harmful to the cardiovascular system,” said Gregory M. Marcus, MD, MAS, FAHA, chair of the American Heart Association’s 2026 Scientific Statement on Caffeine and Cardiovascular Disease. “While there are biological reasons why this link might be possible, the study does not prove that caffeinated products caused these events, as other factors may have influenced the results of this analysis. Further research is needed to understand whether these stimulant products are truly responsible for the reported cardiac events.” Marcus, who was not involved in this study, is also a professor of medicine at the University of California San Francisco School of Medicine and associate chief of the cardiology program for research at University of California San Francisco Health.
What are the details, context, design and limitations of the study?
- Researchers analyzed 28,345 reports in an FDA safety database regarding possible adverse events between 2017 and 2025. Among them, 854 reports mentioned caffeine or energy drinks or dietary supplements containing stimulants. The researchers compared them to 27,491 reports of products without caffeine or other stimulants.
- Reports classified as related to caffeine and stimulant products included those containing these types of ingredients: caffeine, methylxanthines (theobromine, guarana, yerba mate, green tea/coffee extracts), and sympathomimetics (synephrine, yohimbine, ephedra, DMAA, higenamine).
- The researchers grouped products by ingredient, not brand, so the results point to product types rather than a single brand or product.
- The study authors emphasized that the analysis design only identified associations between caffeinated products and cardiac events voluntarily reported to the FDA; results cannot prove that these products directly caused cardiac problems or events.
- Additionally, because reports of adverse events associated with caffeinated products were submitted by consumers/the general public, physicians, and manufacturers who voluntarily informed the FDA of these events, it is not known how many people consumed these products without experiencing cardiac events, or how many people experienced cardiac events and did not report them.
Co-authors, disclosures, and funding sources are listed in the abstract.
Statements and conclusions of studies presented at scientific meetings of the American Heart Association are solely those of the study authors and do not necessarily reflect the policy or position of the Association. The Association makes no representations or warranties as to their accuracy or reliability. Abstracts presented at the Association’s scientific meetings are not peer-reviewed, but rather selected by independent review panels and are reviewed for their potential to add to the diversity of scientific questions and viewpoints discussed at the meeting. The results are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.
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