Men and women often start replacing hormones between the ages of 35 and 40. It’s best to not wait. If you’ve been to your doctor and have been told that your levels are “normal,” that isn’t necessarily good news to you. “Optimal” levels fight disease AND make you feel better. In addition, your doctor may not be testing all essential hormone levels. There’s more to your body than your thyroid, and there’s more to your thyroid than a TSH level.