In people who are deficient in these nutrients (not uncommon, particularly in those who have been taking synthetic thyroid drugs for years) this conversion doesn't happen optimally. (stonetreeclinic.com)
Natural thyroid drugs contain natural forms of the thyroid hormones T4 and T3, as well as other co-factors, and some patients and practitioners find them more effective than the conventional hypothyroidism treatment, levothyroxine (a synthetic form of the T4 hormone.) (holtorfmed.com)
Alternative physicians tend to prefer natural desiccated thyroid drugs like Armour or Naturethroid, drugs that include both hormones. (verywellhealth.com)