CD4 and hyperthyroidism: They administrated 120 mg of iodide (5 drops of Lugol's solution three times per day) to eight patients with hyperthyroidism and found that T4 secretion decreased as early as 12 hours after administration, reached a plateau effect within 3.5–6 days, and caused a sharp rise in serum T4 concentration to thyrotoxicosis range within 4 or 5 days after withdrawal of iodide [6].