If a person is given thyroid medicine when the thyroid blood tests are normal, or when the thyroid gland is normal, it will damage the thyroid gland.

FALSE. Whereas thyroid medicine can rest a person’s thyroid system for a time no studies have ever shown that it can damage a previously healthy gland, preventing it from functioning normally again after the medicine is discontinued. Actually, resting the thyroid system in the right way can often reset it, much like birth control pills can suppress a woman’s own female hormone system for a time to restore a normal menstrual cycle. For example, the thyroid gland function of patients who come in with their thyroid glands suppressed with thyroid medicine for the past 20 years routinely have their own thyroid gland function come back up again when they’re weaned off.