What Happens to Your Blood Pressure When You Take Magnesium

1Magnesium is found in foods like leafy greens and nuts.Credit: Anastasiia Krivenok / Getty ImagesFact checked by Nick Blackmer

Why this matters: Magnesium supplements may lower blood pressure, especially in people with hypertension.

What you can do: Ask your healthcare provider whether a magnesium supplement makes sense for you.

The payoff: Keeping your blood pressure in a healthy range can lower your risk of heart disease, heart attack, and stroke.

Magnesium supplements are probably best known for helping with sleep and constipation—but what about blood pressure?

Magnesium supplements may help lower blood pressure, particularly for people with hypertension (high blood pressure).

A 2025 research review found that magnesium supplements lowered systolic blood pressure (the top number) by about 3 mm Hg and diastolic blood pressure (the bottom number) by about 2 mm Hg.

The results were even greater for people with hypertension (who were already taking blood pressure medication). That group saw reductions of about 8 mm Hg in systolic blood pressure and 3 mm Hg in diastolic blood pressure.

More research is needed to determine how magnesium lowers blood pressure. But evidence suggests that it may help relax blood vessels and regulate sodium and fluid balance, both of which can reduce pressure within the arteries.

Many people in the U.S. don’t get enough magnesium from their diet, and if you’re falling short, a supplement can help fill the gap. The recommended dietary allowance (RDA) of magnesium per day is:

Ages 19 to 30: 400 mg for men, 310 mg for women

Ages 31 and older: 420 mg for men, 320 for women

If you decide to add a magnesium supplement, the safe upper limit is 350 mg for all adults, not including magnesium found naturally in food.

However, it’s best to check with a healthcare provider before adding a new supplement to your regimen. It’s generally advised to meet your nutritional needs through food if possible. Magnesium supplements can also interfere with certain medications, and too much magnesium may be dangerous for people with kidney disease.