Recent research indicates that American livers have been facing increasing challenges over the past few decades, and you might find the primary cause quite unexpected.
A study from the University of Virginia examined national poison center data focusing on liver injuries linked to external substances. Since 2000, cases of such injuries have surged, with acetaminophen—commonly known as Tylenol—being the leading culprit when taken alone.
The results reveal that liver injuries caused by external factors “have significantly increased over the past 25 years, with [acetaminophen taken alone] becoming a major and persistent cause,” the researchers noted in their paper, published Wednesday in the journal Clinical Gastroenterology and Hepatology.
Liver injuries
The study aimed to track shifts in liver injuries caused by xenobiotics, which are substances foreign to the body. This category covers medications, dietary supplements, recreational drugs like alcohol, and environmental pollutants.
Utilizing the National Poison Data System, the researchers focused on reports of lab-confirmed liver injuries related to xenobiotics. They gathered around 220,000 such reports involving individuals over 15 from the years 2000 to 2024. They found that the adjusted rate of these injuries increased from 10.9 exposures per million to 52.9 per million during the study period—a more than fourfold rise. Notably, over 80% of annual exposures resulted in hospitalizations, indicating the seriousness of the injuries.
Most liver injuries—about 90%—were tied to medications, with acetaminophen alone making up a significant proportion (33% in men and 45% in women). This trend mirrors the overall increase in acetaminophen-related injuries over time. Alcohol was the second-largest contributor, with cases rising during the pandemic, which echoes findings from other studies. While recreational drugs and dietary supplements also showed an uptick in injuries, they remained relatively minor contributors.
Lessons to take away
Acetaminophen is a widely used pain and fever reducer. It’s generally easier on the stomach compared to other common pain relievers, and it’s often deemed safe for pregnant women. Contrary to recent claims suggesting a link to autism, research indicates that using it during pregnancy does not seem to elevate autism risk. However, it’s long been recognized that acetaminophen can lead to liver damage, particularly when consumed in excessive amounts.
The researchers pointed out that incidents involving medications combining acetaminophen with other drugs fell significantly—by 60% to 85%—after the FDA implemented new limits in the 2010s on the amount of acetaminophen allowed in these combinations. This suggests that effective regulatory measures can help mitigate such injuries. On a positive note, recent poison center data indicates that rates of acetaminophen-related injuries have stabilized over the last three years.
Nevertheless, at least 90,000 Americans report toxic exposures to acetaminophen annually. The ongoing rise in cases specifically linked to acetaminophen alone highlights the need for better public education about the potential dangers of the drug.
While taking Tylenol occasionally for a headache is generally safe, moderation is key in both medicine and life.
People might exceed the recommended dosage to manage severe pain or because they mistakenly believe that more is always better. However, the risk of liver injury escalates with overdose. Product guidelines suggest a maximum of 4,000 milligrams per day, yet experts typically recommend aiming for no more than 3,000 milligrams if possible. If higher doses seem necessary, consulting a doctor is advisable.
