My 3 year old son is currently going through chelation for mercury and his DAN doctor also instructed me to administer DMSA (100 mg)3x daily on days 1-3 of the 14 day cycle. I also read somewhere about the spacing dosing at 4 hour intervals and was doing so but my son seemed to be sleeping a lot. I questioned his doctor who said that 4 hour dosing schedule should not be followed. He advised that DMSA should be given at breakfast, again in the afternoon and then at bedtime. The DAN protocol called for the same amount of DMSA over the course of one day but at 150mg, 2x 8 hours apart. Otherwise if I followed the 4 hour dosing schedule, my son would have been getting 300mg/day in a 12 hour period. The DAN protocol called for 300mg/day in a 16 hour period. Indeed, you most definitely know your child best. However, DMSA can have serious consequences and I would follow your doctor's instructions on administration of it or question your doctor if you have further concerns.