tudca is the best liver support you can find but thats far from enough when using an oral... what about your blood pressure, kidneys, lipids just to name a few? here is a link to my all in one organ st product which is covering all the bases for you... https://www.dganutrition.com/product/organ-st/
research indicates anywhere from 500-2000 mg per day... if you are running an all in one, 250 mg is more than sufficient, if ran alone, at least 500 per day..
TUDCA is probably the best ingredient for keeping the liver healthy. I would just take N2Guard since it not only has a full serving of TUDCA but also tons of other ingredients like NAC and milk thistle.