Drug interactions
Glandular products + Levothyroxine
Severity: Moderate
Glandular products and Levothyroxine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Thyroid glandular extracts contain thyroid hormones, so taking them with levothyroxine duplicates therapy. This can cause excess thyroid hormone effect, with palpitations, tachyarrhythmia, anxiety, weight loss and bone loss over time.
What this interaction means in plain words
Glandular products and Levothyroxine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Additive thyroid hormone activity from duplicate thyroid hormone sources.
What to do
Avoid combining thyroid extracts with levothyroxine and use a single standardized thyroid preparation. Check TSH and free T4 and adjust the levothyroxine dose if an extract has been used.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Glandular products and Levothyroxine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Levothyroxine
Frequently asked questions
Can I take Glandular products with Levothyroxine?
MediHelp rates the interaction as moderate. Glandular products and Levothyroxine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Thyroid glandular extracts contain thyroid hormones, so taking them with levothyroxine duplicates therapy. This can cause excess thyroid hormone effect, with palpitations, tachyarrhythmia, anxiety, weight loss and bone loss over time.
How serious is the interaction between Glandular products and Levothyroxine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining thyroid extracts with levothyroxine and use a single standardized thyroid preparation. Check TSH and free T4 and adjust the levothyroxine dose if an extract has been used.
What other medicines interact with Levothyroxine?
MediHelp also lists interactions of Levothyroxine with, for example, Cholestyramine, Sodium iodide i-131, Tiratricol. The full list is on the Levothyroxine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
