Magnesium and Blood Pressure: Evidence, Usage, and Safety
Reading time: 9–12 minutes • Educational only.
Quick take
A 34-trial meta-analysis (median 368 mg/day for ~3 months) found SBP −2.0 mmHg and DBP −1.8 mmHg on average vs. placebo. Effects are small and vary by dose, duration, baseline BP and study quality.
What it is & why it’s relevant
Magnesium is involved in vascular tone and BP regulation. Mild dietary shortfalls are common, especially with low-legume/green/whole-grain diets. Some supplement forms dissolve/absorb better than others.
How people typically use it (study-aligned)
- Elemental dose: commonly 200–400 mg/day for 8–12+ weeks (do not exceed the UL 350 mg/day from supplements unless under clinician care). Forms that dissolve well (e.g., citrate, lactate, chloride) are generally more bioavailable than poorly soluble forms like oxide. GI tolerance varies; glycinate is often gentler.
- When to take: with food if GI upset; keep a consistent time.
- How to track: use our 7-day average before and after a 2–4-week window: How to Measure & Track.
Medication timing & interactions (important)
- Bisphosphonates (e.g., alendronate): separate magnesium by ≥2 hours.
- Antibiotics (tetracyclines/quinolones): take antibiotic ≥2 hours before or 4–6 hours after magnesium.
- Levothyroxine: minerals can impede absorption; separate by several hours (clinicians commonly advise ~4 hours).
- Diuretics: loops/thiazides can deplete magnesium; potassium-sparing diuretics can raise levels—coordinate testing.
- Long-term PPIs: can cause hypomagnesemia; monitoring may be needed.
Pair magnesium with the fundamentals
Educational Disclaimer: This article is for educational purposes only and is not medical advice.
