Energy drinks and stimulant supplements tied to heart event reports in young adults

New preliminary research has found that caffeinated energy drinks and stimulant supplements appeared disproportionately more often in FDA reports of serious cardiovascular events, including cardiac arrest and heart attacks. This was particularly apparent among adults aged 18 to 34. 

The study authors from the University of Virginia School of Medicine in Charlottesville, US, will present these findings at the American Heart Association’s Scientific Sessions 2026 (Nov 6–9) in Chicago, US.

While the science behind energy drinks and other stimulant-containing supplements remains limited, the American Heart Association says that healthcare professionals have recorded cases of arrhythmias or sudden cardiac death in people who had consumed these products — many of them young adults with no known heart disease risks.

“These products are marketed as everyday pick-me-ups and sold next to soda and bottled water, so most people assume they carry no real risk,” says study author Sai Samayamanthula, a fourth-year medical student at the University of Virginia School of Medicine.

“For many healthy people, if these products are consumed occasionally, the risk is probably small. However, individuals who consume energy drinks or other stimulant-containing supplements regularly can quickly exceed the recommended daily limit for caffeine, so it’s important for people to know that there may be a risk of cardiovascular harm with these products.”

Authors of the study still do not fully understand why the association between caffeine and stimulant products and heart events was so frequent among young adults.

The FDA data were based on reports submitted by consumers, clinicians, and manufacturers, making it difficult to estimate how many people consumed these products without experiencing any cardiac events or how many experienced these conditions and did not report their experience.

Consolidating reports

The University of Virginia researchers analyzed data from the FDA safety database to compare reports of adverse reactions related to products containing caffeine and other stimulants compared to FDA-regulated foods and dietary supplements such as soft drinks, meal replacement shakes, protein bars, smoothies, and vitamins.

The data included reports from individuals aged 13 and above between 2017 and 2025. In total, the study analyzed 28,345 reports made to an FDA safety database regarding possible adverse events during this period.

Among these reports, 854 mentioned caffeine- or stimulant-containing energy drinks or dietary supplements. Researchers then compared these with 27,491 reports about products without caffeine or other stimulants.

Authors of the study still do not fully understand why the association between caffeine and heart events was so frequent among young adults.

Reports categorized as being related to caffeine and stimulant products included those with certain ingredients: caffeine, methylxanthines and their sources (theobromine, guarana, yerba mate, and green tea/coffee extracts), and sympathomimetics (synephrine, yohimbine, ephedra, methylhexanamine, and higenamine).

In particular, the FDA has banned ephedra and methylhexanamine from dietary supplements.

Researchers grouped products by ingredient rather than by brand, so the findings point toproduct types rather than any single brand or product.

Records of heart abnormalities

According to the analysis, cardiac arrest was reported about 11 times more often in connection with caffeine- and stimulant-containing products compared with products without these ingredients.

Reports involving energy drinks and supplements were around 4.5 times more likely to include heart attacks and four times more likely to include ventricular arrhythmias (abnormal rhythms in the heart’s lower pumping chambers) or heart palpitations.

The analysis highlights similar patterns linking caffeinated energy drinks and stimulant supplements to reports of other heart conditions, including elevated heart rate (nearly three times more often), chest pain (2.71 times more often), and fainting (about two times more often).

Findings reveal around 45% of reports linking caffeine- and stimulant-containing products to cardiovascular events involved adults aged 18 to 34.

Moreover, the researchers observed similar patterns in reports involving both men and women.

“Our findings support the case for more systematic safety monitoring of caffeine- and stimulant-containing products. In addition, healthcare professionals should remember to ask their younger patients who have palpitations, chest pain, or fainting spells if they recently or regularly consume these products,” Samayamanthula comments.

However, the study authors stress that their analysis’ design only highlighted associations between caffeinated products and cardiac events, meaning that these results cannot prove that these products directly caused any heart conditions or events.

Safety guidance

This year’s American Heart Association scientific statement on caffeine and cardiovascular disease advises that consuming up to 400 mg of caffeine per day — or the equivalent of up to five eight-ounce cups of regular black caffeinated coffee — is generally safe for most adults.

The American Heart Association advises that consuming up to 400 mg of caffeine per day is generally safe for most adults.Compared to brewed coffee, some energy drinks contain up to three times as much caffeine per fluid ounce, and some pre-workout supplements contain more than 12 times as much caffeine per fluid ounce, according to the association.

Since the US FDA regulates energy drinks and stimulant supplements as foods or dietary supplements rather than medications, it notes that these products do not go through the same premarket safety testing required for medications.

“This study raises concerns that products with very high amounts of caffeine may be harmful to the cardiovascular system,” says Gregory Marcus, M.D., chair of the 2026 American Heart Association scientific statement on caffeine and cardiovascular disease.

“Although there are biological reasons why that connection could be possible, the study does not prove that caffeine products cause these events, because other factors may have influenced the results found in this analysis. More research is needed to understand whether these stimulant products are truly responsible for the reported heart-related events.”

The findings build on a recent study that linked weekly caffeine intake in children — mainly from soft drinks — to lower cortical surface area and poorer later mental health.

Jitters-free energy in demand

According to American Heart Association figures, sales of caffeinated energy drinks have more than doubled over the past decade, reaching more than US$20 billion in 2024.

Consumers are increasingly seeking “jitters-free” solutions for energy and mental clarity, according to recent consumer research by the AI-native research company Knit. The survey involving US consumers found that 27.3% consider it difficult to obtain more energy without spiking nerves, while 30% are demanding more effective solutions.

One example of formula innovation to address this need is Ethical Naturals’ MachaWave solution, which blends high-grade organic matcha with AlphaWave, the company’s form of L-theanine produced through a proprietary fermentation and purification process. According to the supplier, pairing these ingredients helps reduce nervous tension and deliver balanced energy.