From the Research
For a patient taking 120 mg of Armour Thyroid, an approximate equivalent conversion to Synthroid and Cytomel would be 200 mcg of Synthroid (levothyroxine) and 50 mcg of Cytomel (liothyronine) daily. This conversion is based on the general principle that 1 grain (60 mg) of Armour Thyroid is roughly equivalent to 100 mcg of T4 and 25 mcg of T3, as supported by the study 1. However, it's crucial to note that this is not an exact science, and individual patient responses may vary. The conversion should be done under close medical supervision, with regular monitoring of thyroid function tests and adjustment of dosages as needed. Some key points to consider when making this conversion include:
- The ratio of T4 to T3 in desiccated thyroid extract is approximately 4:1, as noted in the study 1.
- The mean daily dose of desiccated thyroid extract needed to normalize serum TSH contains approximately 11 mcg of T3, but some patients may require higher doses, as seen in the study 1.
- Patients may require a period of dose titration to achieve optimal thyroid hormone levels and symptom control.
- It's also important to remember that switching between different thyroid hormone preparations can affect the body's response, and patients should be educated about potential changes in symptoms during the transition period. Additionally, a study from 2021 2 found that some patients with levothyroxine unresponsive hypothyroidism experienced significant symptomatic benefit and improvement in quality of life when treated with natural desiccated thyroid, suggesting that this may be a viable option for some patients. However, the most recent and highest quality study 1 provides the best guidance for making this conversion, and close medical supervision and monitoring are essential to ensure the best possible outcome for the patient.