Should you take a magnesium supplement to lower your blood pressure?

Taking magnesium supplements has become popular in recent years, especially among people hoping to ease muscle cramps or sleep more soundly. But for both of those possible perks, the evidence has been mixed. As far as the FDA is concerned, a reduced risk of high blood pressure is the only potential advantage from magnesium intake that warrants a mention (see “A qualified health claim for magnesium”).

An analysis published Sept. 26, 2025, in Hypertension summarized the latest evidence. When researchers pooled findings from 38 randomized controlled trials, they found that magnesium supplements may modestly lower blood pressure, especially in two groups: people with high blood pressure and those with low magnesium levels. In fact, dietary surveys suggest that most people in the United States — especially men over age 70 — don’t get the recommended amount of magnesium from the foods they eat. Men should get 420 milligrams (mg) a day, and women should consume 320 mg a day.

Compared with taking a magnesium supplement, however, a dietary approach may be a more effective strategy for controlling blood pressure, says Dr. Stephen Juraschek, associate professor of medicine at Harvard Medical School. One way is to make an effort to include magnesium-rich foods in your diet (see “Good sources of magnesium”). But the heart-healthy Dietary Approaches to Stop Hypertension (DASH) diet is an even better (and evidence-based) way to reduce your blood pressure, he says.

How DASH delivers

The DASH diet recommends eating four to five servings of fruits and a similar number of servings of vegetables each day. Fresh produce is naturally low in sodium (a main dietary demon when it comes to high blood pressure) but high in magnesium and potassium, another mineral that seems to help lower blood pressure. The DASH diet also includes two to three daily servings of low-fat or fat-free dairy products, which provide calcium, yet another mineral linked to healthy blood pressure. Other key components — whole grains, lean protein, beans, and nuts — also provide an array of vitamins, minerals, and other nutrients.

“The whole idea behind DASH was to create a healthy eating pattern instead of a reductionist, silver-bullet approach focused on single foods or nutrients,” says Dr. Juraschek.

Source: Office of Dietary Supplements, National Institutes of Health.

Does anyone need a magnesium supplement?

Certain medical problems may leave people prone to low magnesium levels, such as Crohn’s disease, celiac disease, or poorly controlled diabetes. A blood test can measure whether you’re getting enough magnesium. The normal range for blood magnesium is 1.7 to 2.2 milligrams per deciliter (mg/dL). But check with your doctor before taking a magnesium supplement.

“In general, it’s best to stay within the recommended dietary amounts for nutrients and not take an excess of any single micronutrient,” says Dr. Juraschek. To make sure you’re meeting the dietary allowance for most vitamins and minerals, you might consider taking a multivitamin. “People often get into a pattern of eating the same foods week after week, and some may end up with deficits in certain micronutrients that can be difficult to pinpoint. A multivitamin covers the bases,” says Dr. Juraschek. However, it’s worth noting that there’s no evidence that taking a daily multivitamin prevents cardiovascular disease, he adds.

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