Acetaminophen like Tylenol depletes glutathione and damages the liver (1), but chances are people won't be getting away from using them anytime soon. What can be done is help protect the liver from damage induced through supplementation.
Silymarin (from milk thistle) may serve as a support while taking acetaminophen. In a rat study, acetaminophen decreased glutathione and glycogen quickly (1). Unlike the control, rats taking silymarin showed no significant increase in lipid peroxidation or disruption of enzyme activities (1). Thus, while the silymarin didn't prevent glutathione depletion in rats, it did protect the liver possibly through antioxidant properties and helped with restoring glycogen (1).
Human studies have not yet been conducted, but many doctors already recommend silymarin supplements based on its recent research (2).
Reference
1. Muriel, P; Garciapina, T; Perez Alvarez, V; Mourelle, M. Silymarin protects against paracetamol-induced lipid peroxidation and liver damage. J Appl Toxicol. 1992 Dec; 12(6): 439-42
2. http://health.med.umich.edu/healthcontent.cfm?xyzpdqabc=0&id=6&action=detail&AEProductID=HW_CAM&AEArticleID=hn-1072008&AEArticleType=Cam
