That headline is too absolute. Magnesium supplements aren’t universally forbidden with particular medications, but magnesium can interfere with absorption of some drugs or have additive effects with others.
Important interactions
-
Certain antibiotics — magnesium can bind to tetracyclines (such as doxycycline) and fluoroquinolones (such as ciprofloxacin), reducing absorption. They generally need to be taken several hours apart.
-
Levothyroxine — magnesium can reduce its absorption. It should generally be separated from magnesium supplements.
-
Bisphosphonates — medicines such as alendronate can have reduced absorption when taken with magnesium.
-
Some diuretics and other medicines affecting magnesium levels — these can alter how much magnesium your body retains or excretes.
-
Kidney disease + magnesium supplements — impaired kidneys may have difficulty removing excess magnesium, making supplementation potentially dangerous.
Don’t interpret this as “never take magnesium”
If you’re taking a prescription medication, check the exact drug and timing with a pharmacist or doctor rather than stopping either medication.
Also remember that magnesium in ordinary foods—such as nuts, beans, whole grains, and leafy vegetables—is generally different from taking a concentrated magnesium supplement.
If you give me the medications you’re taking, I can check which ones interact with magnesium and explain the appropriate spacing between them.
