could be 250 milligrams, 500. some even are a full gram of tylenol. the magic number i will tell you they say if you're taking over 4 grams of acetaminophen in a day, that could just be a few extra strength tylenols, they say that's too much. that could potentially cause problems, serious problems with your liver, causing the liver to actually start to fail and requiring more drastic medical measures. >> i mean, a lot of people though take products with acetaminophen without even thinking there might be consequences after a night of drinking to prevent a hangover. is that something bad or somebody who has a shoulder -- i just had shoulder surgery and i've been taking one or two a day just to kind of deal with the pain. is that bad? >> so here's what i would say. first of all, with regard to drinking, i think it's a bad idea to take acetaminophen if you've been drinking to try and prevent a hangover. that's a bad idea. people can write that one down. these both alcohol and acetaminophen are both going to actually do a little bit of an insult to your liver. you just don't need that.