What trials found
34 trials involving about 2,000 people, taking around 370 mg a day for about 3 months, found about −2.0/−1.8 mmHg.
What “natural” means here
Magnesium is sometimes called a “natural calcium channel blocker” because it competes with calcium in blood vessel muscle. But it's far weaker than the medicine, and it isn't a “natural beta blocker”. It's a cofactor that helps your body use vitamin D.
Food first
Magnesium-rich foods include pumpkin and sunflower seeds, almonds, beans, spinach and leafy greens, and whole grains. Magnesium isn't in the AHA lifestyle recommendations; DASH-style eating naturally includes magnesium-rich foods.
Supplement cautions
Supplements can cause diarrhea, can build up with kidney disease, and can interact with some antibiotics and other medicines.
In-app “Myth or fact?” cards offer short, sourced answers to common blood pressure claims.
How FourNumbers helps
FourNumbers can't tell you whether a supplement or diet is right for you — that's for you and your doctor. What it can do is show what's actually happening to your numbers: log readings the right way, keep your medicines and supplements in one list, and bring a report to your doctor.
Download on iPhoneQuestions people also ask
Sources
Related guides
- Does vitamin D lower blood pressure?
- Potassium and blood pressure: food, powders and salt substitutes
- Supplements for blood pressure: what the evidence says
Last checked: October 2026.