The headline “NEVER use magnesium if you are taking any of the following medications” is an oversimplification. Magnesium supplements can interact with certain medications, but they are not universally unsafe. Often, the interaction can be managed by taking the medications at different times.
Here are some important interactions:
- Certain antibiotics
- Magnesium can reduce the absorption of some antibiotics, including tetracyclines and fluoroquinolones. They are usually taken several hours apart.
- Levothyroxine
- Magnesium can decrease its absorption. It is generally recommended to separate the doses by at least 4 hours.
- Bisphosphonates (used for osteoporosis)
- Magnesium can interfere with absorption. Follow the timing instructions provided with the medication.
- Some HIV medications
- Certain antiretroviral drugs can interact with magnesium-containing products.
- Some oral iron supplements
- Taking magnesium and iron together may reduce absorption of one or both.
Other considerations
- People with significant kidney disease should not take magnesium supplements without medical advice because the kidneys may not be able to remove excess magnesium.
- Magnesium can also interact with some other medications or supplements depending on the specific product and dose.
Does this apply to magnesium-rich foods?
Usually no. These interactions are mainly a concern with magnesium supplements or magnesium-containing antacids/laxatives, not the amount of magnesium found naturally in foods such as nuts, seeds, legumes, and leafy green vegetables.
Before starting a magnesium supplement
Tell your healthcare professional or pharmacist about all the medicines and supplements you take. They can advise whether magnesium is appropriate and whether doses should be separated to avoid interactions.
If you tell me which medications you’re taking, I can explain whether magnesium is likely to interact with them.
