Acetaminophen -- the active ingredient in Tylenol -- is bad news for your liver if you take too much of it. The same is true for alcohol. So should you avoid popping Tylenol to take the edge off the morning-after hangover? Probably yes -- although the biology behind how the two substances interact is more complex than you might imagine. UPDATED VERSION! (Previous version contained a frustrating error - for which we apologize profusely!) FURTHER RESOURCES Medline Plus: Trusted Health Information for You. Acetaminophen. U.S. National Library of Medicine, National Institute of Health. AHFS Consumer Medication Information. Revised: 15 August 2013. Accessed online: 27 September 2013. http://www.nlm.nih.gov/medlineplus/druginfo/meds/a681004.html FDA information on acetaminophen toxicity: http://www.fda.gov/Drugs/DrugSafety/SafeUseInitiative/ucm230396.htm Mayo Clinic: Acetaminophen and Children: Why Dose Matters: http://www.mayoclinic.com/health/acetaminophen/HO00002 Pro Publica report on acetaminophen risks: http://www.propublica.org/article/tylenol-mcneil-fda-use-only-as-directed L.E. Schmidt, K Dalhoff, H.E. Poulson. Acute versus chronic alcohol consumption in acetaminophen-induced hepatotoxicity. Hepatology (32) 2002; p.876-882. http://www.ncbi.nlm.nih.gov/pubmed/11915034 F. Yang, D. A. Beard. Thermodynamically based profiling of drug metabolism and drug-drug metabolic interactions: A case study of acetaminophen and ethanol toxic interactions. Biophysical Chemistry, 120 (2) p. 121-134. 20 March 2006. Accessed online: 27 September 2013. http://dx.doi.org/10.1016/j.bpc.2005.10.013 P. Zhao, T.K. Kalhourn, J.T. Slattery. Selective mitochondrial glutathione depletion by ethanol enhances acetaminophen toxicity in rats. Hepatology (36); p. 326-335. 2002. K. Thummel, et al. Ethanol and production of hepatotoxic metabolite of acetaminophen in healthy adults. Clinical Pharmacology and Therapeutics (2000) 67; p. 591-599. http://dx.doi.org/10.1067/mcp.2000.106574 THIS WEEK'S RISK BITES TEAM: Producer: Andrew Maynard Research Director: David Faulkner Background Research: Alyssa berry Risk Bites is your guide to making sense of risk. We cover everything from understanding and balancing the risks and benefits of everyday products, to health science more broadly, to the potential impacts of emerging technologies, to making sense of risk perception. If you enjoy our videos, please subscribe, and spread the word!