Thyroid medicine (T4 or T3) is absolutely necessary and something “you’ll probably need for life” one minute if your blood tests are low. Then, the medicine automatically becomes very bad for you the next if your tests are normal.

Wait a minute. Thyroid hormones (T4 or T3) have been floating around in our bodies since birth, and they are absolutely necessary for good health. There is nothing inherently bad about the molecules; they can’t and haven’t directly damaged the tissue of your heart, brain, or other tissues. There is no evidence that suggests that thyroid hormones, when used properly, can damage the body in any way. But of course, thyroid hormones are medicine, and as with all medicines, should be used only under the thoughtful supervision of a doctor. Taking thyroid medicine is not completely without risk, as nothing is.