Magnesium is an important mineral, but magnesium supplements can interact with some medications. If you take prescription medicines, it’s best to check with a healthcare professional or pharmacist before adding magnesium supplements.
Medications that may interact with magnesium
- Certain antibiotics
- Magnesium can bind to some antibiotics in the digestive tract and reduce how much medicine your body absorbs.
- Examples include:
- Ciprofloxacin and other fluoroquinolone antibiotics
- Doxycycline and other tetracycline antibiotics
- Taking them several hours apart is often recommended, but follow your prescriber’s instructions.
- Thyroid hormone replacement
- Magnesium may reduce absorption of Levothyroxine.
- It is commonly advised to separate doses by several hours.
- Bisphosphonates for osteoporosis
- Magnesium can interfere with absorption of medicines such as Alendronate.
- These medications often require careful timing away from minerals and supplements.
- Some blood pressure medications
- Magnesium may affect blood pressure and, in some cases, may add to the effects of blood pressure-lowering medicines.
- People taking medicines such as calcium channel blockers or other antihypertensives should ask a clinician about appropriate use.
- Diuretics (“water pills”)
- Some diuretics can change magnesium levels in the body.
- Examples include Furosemide and Hydrochlorothiazide.
- Medications that affect kidney function
- People with kidney disease need extra caution because the kidneys remove excess magnesium.
- Too much magnesium can build up and cause problems.
Possible signs of too much magnesium
Seek medical advice if you develop:
- Nausea or vomiting
- Diarrhea
- Unusual weakness
- Low blood pressure
- Confusion
- Slow heartbeat (in severe cases)
Magnesium from food (such as nuts, seeds, legumes, and leafy greens) is generally handled differently from high-dose supplements. If you share the name and dose of your medication(s) and the type of magnesium supplement you’re considering, I can help check for known interactions.
