I also think that it takes several months for the toxins to be removed & replaced by Iodine and for the thyroid to recover. I can't say how long exactly, but it took a good 6 months before my prostate recovered from its problems after starting iodine. The prostate is one of the organs impacted by Iodine deficiency. Also, the Lugols skin test showed a remarkable change over 6 months. The stain on my wrist disappeared in just less than 3 minutes when I started, and well over 3 hrs after 6 months.