From the Guidelines
Dose adjustment is necessary when switching from Natural Products (NP) to Armour Thyroid (dessicated thyroid) due to differences in T3 and T4 hormone content, requiring individualized monitoring and potential adjustments to achieve optimal thyroid hormone levels. When making this switch, it's crucial to consider the equivalent dose based on the thyroid content, but also be prepared for adjustments as individual responses to different thyroid formulations can vary significantly due to differences in absorption, bioavailability, and the ratio of T3 to T4 hormones 1. The initial dose of Armour Thyroid should be equivalent to the NP dose in terms of grain content, but subsequent adjustments should be guided by thyroid function tests performed after 6-8 weeks, as well as clinical assessment of symptoms such as fatigue, weight changes, or heart palpitations. Key considerations include:
- Starting with an equivalent dose based on thyroid content (e.g., 1 grain of NP Thyroid to 1 grain of Armour Thyroid)
- Monitoring thyroid function tests after 6-8 weeks to assess the appropriateness of the dose
- Adjusting the dose based on lab results and clinical symptoms, with increases typically done in 12.5 mcg to 25 mcg increments, as suggested for standard thyroid replacement therapy adjustments 1
- Regular follow-up, at least annually or sooner if the patient's status changes, to ensure the maintenance dose remains appropriate. It's essential to work closely with a healthcare provider to adjust thyroid medication, as individual responses can vary widely and self-adjustment can lead to suboptimal treatment or adverse effects.
From the Research
Dose Adjustment When Switching from Natural Products to Armour Thyroid
- The need for dose adjustment when switching from Natural Products (NP) to Armour Thyroid (desiccated thyroid) is not directly addressed in the provided studies 2, 3, 4, 5, 6.
- However, the studies suggest that desiccated thyroid preparations like Armour Thyroid have a different T4:T3 ratio compared to the body's natural secretion ratio 2.
- A study found that combined T4 and T3 therapy or desiccated thyroid lead to higher T3 and lower T4 levels compared to T4 monotherapy in hypothyroidism 4.
- Another study reported that some individuals with levothyroxine unresponsive hypothyroidism experienced significant symptomatic benefit and improvement in quality of life when treated with natural desiccated thyroid (NDT) preparations like Armour Thyroid 6.
- The dose range of NDT used in this study was 60-180 mg daily, but the study does not provide information on dose adjustment when switching from NP to Armour Thyroid 6.
- A case report highlighted the potential risks of self-administering Armour Thyroid, particularly when combined with other supplements like testosterone, and emphasized the importance of physician monitoring 3.
Key Considerations
- The T4:T3 ratio in desiccated thyroid preparations like Armour Thyroid is different from the body's natural secretion ratio 2.
- Combined T4 and T3 therapy or desiccated thyroid can lead to higher T3 and lower T4 levels compared to T4 monotherapy in hypothyroidism 4.
- Natural desiccated thyroid preparations like Armour Thyroid may be beneficial for some individuals with levothyroxine unresponsive hypothyroidism, but dose adjustment and physician monitoring are crucial 6, 3.