Magnesium can absolutely cause diarrhea—especially when taken in the wrong form or dose. If your magnesium supplement is sending you running to the bathroom, it’s time to take a look at what’s really going on and how to fix it.
Why Does Magnesium Cause Diarrhea?
The most common culprit is magnesium oxide, a form with notoriously low absorption—some studies estimate only about 4% is absorbed by the body. The unabsorbed portion stays in the gut and draws water into the intestines, often resulting in diarrhea. This laxative effect may be useful for occasional constipation, but not when you’re aiming for stress support, better sleep, or muscle recovery.
Many magnesium supplements are buffered—meaning they claim to contain a highly absorbable form like magnesium bisglycinate, but are actually bulked up with magnesium oxide. If you’ve experienced digestive upset from one of these buffered forms of magnesium, you’re not alone.
Other Reasons Magnesium Might Upset Your Stomach
Even well-absorbed forms like magnesium citrate can cause diarrhea if taken in high doses or all at once. Those with sensitive digestion may also react to fillers, additives, or rapid-release formulas that overwhelm the GI tract.
Search terms like “magnesium diarrhea fix” or “best magnesium for sensitive stomachs” often point to the same truth: form matters.
How to Choose a Gentle Magnesium Supplement
-
PrizMAG is our pure magnesium bisglycinate—unbuffered, magnesium oxide-free, and the gentlest option for people who frequently experience diarrhea or have sensitive digestion.
-
MAGtrio combines magnesium bisglycinate, magnesium taurate, and magnesium L-threonate—all highly absorbable, well-tolerated forms. It’s gentle and effective without unwanted bathroom trips.
-
MAG365, our ionic magnesium citrate powder, is suitable for most people and is highly absorbable. While our ionic magnesium citrate is more gentle than most magnesium citrate supplements, it may still cause diarrhea if too much is taken at once. If that happens, simply:
- Split your dose throughout the day for more steady absorption
- Reduce your dose until your stools are comfortably loose, not runny
- Or switch to PrizMAG or MAGtrio if you're still experiencing diarrhea after splitting or reducing your dose of MAG365.
Final Thoughts
If your magnesium supplement is giving you diarrhea, don’t ditch magnesium altogether—just change your formula. The right supplement can deliver all the benefits without the bathroom drama.
All ITL Health magnesium supplements are genuinely pure and formulated for optimal absorption for everyone. Whether you need ultra-gentle support (PrizMAG), a well-rounded trio (MAGtrio), or fast-absorbing powder (MAG365), we’ve got your gut—and your wellness—covered.
SHOP PrizMAG Pure Magnesium Bisglycinate
SHOP MAGtrio: Magnesium Taurate, Magnesium Bisglycinate & Magnesium L-Threonate
Explore our articles on magnesium and digestion: