I've used milkthistle with Sam, the best way to use any type of supplement (so they say!), is to use for say a month (or two), and have a break for a few weeks. I havent had his alt levels checked afterward, but know that it does work to support and rejuvenate the liver. I would usually use it after a course of antis for a couple of months. I used the adult strength dose, just because pwcf are always put on double the usual dose for a 'normal' person their weight/age etc., so I figured the higher dose has greater chance of absorbtion.