I posted this earlier in this thread, but we bought 240mg Milkthistle, open the capsule and give her 120 mg per day, split between morning and evening. Sprinkled on food or a treat. So that's about 1/4 capsule per serving. She's a bantam BR, so she weighs about 3 lbs. Might need more for a bigger hen, but probably not much more.
So possibly half a capsle?