mineral · for irregular digestion
Magnesium Glycinate
Magnesium relaxes gut muscle and draws water in, which would soften stool.
Say that in clinical terms
Magnesium relaxes intestinal smooth muscle, supports peristaltic contractions, draws water into the intestinal lumen for softer stools, and is a cofactor for digestive enzymes. Glycinate form provides gentle, non-osmotic bowel support.
How strong is the research?
2 papers read, 2 supporting.
Tested as: Magnesium oxide (the only form with RCT evidence for constipation/irregular digestion)
Who was studied: The cited study was 3,835 Japanese dietetics students aged 18 to 20.
A proper search found trials of this compound, but not in the form named here — Magnesium oxide (the only form with RCT evidence for constipation/irregular digestion). Evidence for one form is not evidence for another.
How much to take
daily
200–400 mg
Magnesium supports healthy bowel motility. Glycinate form is gentler than citrate or oxide on the GI tract.
Before you take it
- NIH ODS Tolerable Upper Intake Level (UL) for supplemental magnesium is 350 mg/day for adults; the principal adverse effect above the UL is osmotic diarrhea; hypermagnesemia is rare with intact renal function but possible with chronically elevated doses.
- Tetracycline antibiotics (e.g., doxycycline, demeclocycline) and quinolone antibiotics (e.g., ciprofloxacin, levofloxacin): take the antibiotic at least 2 hours BEFORE or 4-6 hours AFTER magnesium supplementation, per NIH ODS. Note: this timing requirement is asymmetric.
- Bisphosphonates (e.g., alendronate): magnesium reduces oral bisphosphonate absorption; take at least 2 hours apart, per NIH ODS.
- Antihypertensive medications (ACE inhibitors, ARBs, calcium channel blockers): magnesium may potentiate blood-pressure-lowering effects; blood pressure should be monitored when these are combined.
- Loop diuretics (furosemide) and thiazide diuretics increase renal magnesium excretion; potassium-sparing diuretics decrease magnesium excretion — both are clinically relevant interactions in common patient populations.
- Long-term proton pump inhibitor (PPI) use reduces intestinal magnesium absorption and causes hypomagnesemia independent of dietary intake.
- Renal insufficiency and chronic kidney disease: impaired renal magnesium excretion substantially increases hypermagnesemia risk; supplementation requires medical supervision.
- The antacid effect seen with magnesium hydroxide, carbonate, and oxide forms is form-specific and does not apply to magnesium glycinate at typical supplement doses.
- Magnesium glycinate produces substantially weaker osmotic laxative activity compared with magnesium oxide, hydroxide, and citrate at equivalent elemental doses — the constipation benefit seen in studies of dietary magnesium or laxative-form supplements may not generalize to glycinate at typical supplement doses
When to take it
Best taken: evening
What we make of it
A snapshot survey of diet in young Japanese women, not a trial of supplements.
The detail
The study is cross-sectional — a snapshot of what young Japanese women ate — not a trial and not about supplements. It cannot show that taking magnesium changes anything.