The Plummer effect is one of several physiological feedforward mechanisms taking place in follicular cells of the healthy thyroid gland and preventing the development of thyrotoxicosis in situations of extremely high supply with iodine.
[1] In 1923 the American physician Henry Stanley Plummer discovered that high-dose iodine may be effective in the treatment of Graves’ disease.
[8] The three different mechanisms of high iodine response, the Plummer effect, the Wolff-Chaikoff inhibition effect, and the adaptive escape phenomenon, synergistically work together to fend off potentially harmful consequences of excess iodine load and ensure thyroid homeostasis.
Therefore, "plummering" with high-dose iodine is only effective in a short time window after the release of radionuclides.
[9] Wrong timing of iodine use may even increase the risk by triggering the Plummer effect.