5mg Average Dose

from reading these forums it seems 5mg is the average dose, but some people experience a die down of positive effects after taking 5mg in the long term and or detox effects such as headaches.

am i reading this correctly? i would like to try this out but am uncertain as to the dosage, i currently have sea kelp which is 250ug (micrograms) per tablet and the label says not to exceed 3 a day which would be less than 1mg, i know its recommended to build up slowly so should i start on 1mg? or how soon should i build up to 5mg?