mineral · for high blood pressure
Magnesium Glycinate
Relaxes the muscle in your blood vessel walls, so blood meets less resistance.
Say that in clinical terms
Magnesium acts as a natural calcium channel blocker, relaxing vascular smooth muscle and reducing peripheral vascular resistance. It also improves endothelial function, increases nitric oxide production, and reduces angiotensin II effects.
How strong is the research?
2 papers read, 2 supporting.
Who was studied: Pooled 34 trials of people with and without high blood pressure. The effect showed up mainly in those who already had it.
How much to take
daily
300–500 mg
Magnesium has modest but consistent blood pressure-lowering effects. Take consistently and monitor BP.
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 may potentiate the BP-lowering effect of antihypertensive medications (ACE inhibitors, ARBs, calcium channel blockers); blood pressure monitoring is specifically warranted in this symptom population when combining magnesium with prescription antihypertensives
When to take it
Best taken: evening
What we make of it
Real but small — about 2 mmHg — and none of the trials used the glycinate form.
The detail
The pooled analysis is sound: 34 trials, 2,028 people, and blood pressure fell by about 2 points top and bottom at a median dose of 368 mg a day over three months. A 2025 update in 2,709 people found much the same, with bigger effects in people who were hypertensive or low in magnesium to start with. Two caveats. None of those trials used glycinate. And no blood pressure guideline recommends magnesium as a first-line treatment.