The only fail-proof cure for hangovers is not to drink alcohol. Besides that, taking milk thistle for hangovers is a good idea. If, after heavy drinking one night, you wake up with a dreaded, yet anticipated, headache and stomach ache, then milk thistle is for you.
When a person drinks alcoholic beverages, his or her liver has to work over time to remove the alcohol from the body. The liver leaves compounds such as glutathione reductase and glutathione peroxidase behind during the process. The build-up of these chemicals can irritate the liver. If one takes milk thistle after drinking, then the liver does not produce as much of those chemicals. That means that the liver can work on filtering the alcohol from the body faster and reducing the effects of the hangover because there is less interference from the glutathione-based chemicals, all thanks to milk thistle.