"Strength" brings up a good point. I have been told by more than one naturopathic doctor friend that using Thyroid Support together with Adrenal Support is often necessary in order to help correct problems of lethargy, weight-gain and weakened immunity. More often than not, adrenal fatigue (low adrenal function) goes hand-in-hand with low thyroid function. Not surprisingly, mercury toxicity can be a cause for both.