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Can I take 50 and Calcium together?

Drug interaction guide

Taking calcium supplements at the same time as levothyroxine can stop your body from absorbing the thyroid medicine properly. This means your thyroid levels could drop, leading to symptoms of an underactive thyroid such as tiredness, feeling cold, weight gain, and dry skin.

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Why this happens

Calcium carbonate (and other calcium salts) can bind to the levothyroxine in your stomach or intestines. This creates a 'clump' that is too large for your body to absorb into the bloodstream, so the medicine simply passes through your system without working.

You must separate the time you take these two medicines. Take your levothyroxine on an empty stomach, at least 30 to 60 minutes before breakfast. Wait at least 4 hours after taking your levothyroxine before taking any calcium supplements or antacids containing calcium.

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Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

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Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 14 Mar 2026 | Originally published
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