Why do doctors not use T3?
In nature, T4 often is converted into T3 so doctors feel that it is not necessary to replace both hormones. However, in nature, many people’s bodies cannot convert these hormones. Often conditions such as depression, medications, certain foods, lack of sleep, or just genetics prevent this normal conversion. This results in a deficiency of active thyroid (T3). These individuals then experience the symptoms of hypothyroidism even in the presence of their replacement T4. This is why they can be on adequate levels of Synthroid for instance and fail to feel better.
