Levothyroxine and Oral Magnesium: Drug Interaction Guide

Quick answer: This combination requires caution. Levothyroxine and Oral Magnesium can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Levothyroxine interacts with Oral Magnesium

Magnesium salts bind or adsorb levothyroxine in the gastrointestinal tract, reducing and destabilizing levothyroxine absorption.

What you should do

Separate administration by at least four hours. Recheck thyroid-stimulating hormone after regular magnesium use begins or ends.

Key facts

Severity

Moderate — caution required

Mechanism

Magnesium salts bind or adsorb levothyroxine in the gastrointestinal tract, reducing and destabilizing levothyroxine abs...

Action

Separate administration by at least four hours. Recheck thyroid-stimulating hormone after regular magnesium use begins o...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Levothyroxine and Oral Magnesium together?

With caution. Separate administration by at least four hours. Recheck thyroid-stimulating hormone after regular magnesium use begins or ends.

What is the severity of this interaction?

The interaction between Levothyroxine and Oral Magnesium is classified as Moderate — caution required. Magnesium salts bind or adsorb levothyroxine in the gastrointestinal tract, reducing and destabilizing levothyroxine absorption.

What should I do if I'm prescribed both?

Separate administration by at least four hours. Recheck thyroid-stimulating hormone after regular magnesium use begins or ends. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.