It seems to vary from individual to individual. I started very slow at less than 30 mg (1 drop of Trapper's SSKI ) and seem to do better placing it on my skin for absorption. There are some testimonials here (search High On Water) of people using even up to 1 gram or thereabouts per day! Also, it seems most tolerate SSKI better than Lugol's or they mix the dosages as well.