From the Research
Thyroid labs should be rechecked approximately 6-8 weeks after completely stopping Armour (desiccated thyroid) therapy. This timeframe allows the body's hypothalamic-pituitary-thyroid axis to reset and for endogenous thyroid function to stabilize, as suggested by the most recent and highest quality study available 1. When discontinuing Armour, it's generally recommended to taper the dose gradually rather than stopping abruptly, especially if you've been on treatment long-term or at higher doses. During this transition period, patients should monitor for symptoms of hypothyroidism such as fatigue, cold intolerance, weight gain, or constipation. The specific labs that should be checked include TSH (thyroid stimulating hormone), free T4, and possibly free T3. These tests will help determine if the patient's natural thyroid function has recovered adequately or if alternative thyroid replacement therapy is needed. If symptoms of thyroid dysfunction occur before the 6-8 week mark, earlier testing may be warranted. After initial testing, follow-up labs may be needed at 3-6 month intervals until thyroid function stabilizes.
Some key points to consider when stopping Armour thyroid therapy include:
- Gradually tapering the dose to avoid abrupt withdrawal
- Monitoring for symptoms of hypothyroidism during the transition period
- Checking TSH, free T4, and possibly free T3 levels to assess thyroid function
- Considering earlier testing if symptoms of thyroid dysfunction occur before the 6-8 week mark
- Following up with labs at 3-6 month intervals until thyroid function stabilizes, as recommended by recent studies 2, 1.
It's also important to note that the decision to stop Armour thyroid therapy should be made under the guidance of a healthcare provider, taking into account individual patient factors and medical history. Additionally, some studies suggest that desiccated thyroid extract may be beneficial for certain patients with hypothyroidism, particularly those who have not responded to levothyroxine therapy 3, 4. However, the most recent and highest quality study available 1 provides the best guidance for clinical practice.