Magnesium is a popular supplement for improving sleep, but it may also help lower blood pressure. Although there\u2019s no single ideal time to take it, other factors may influence how effectively it supports blood pressure.\n<\/p>\n
Scientists are still learning how magnesium supplements affect blood pressure<\/a>. So far, results are most promising for people with abnormally high blood pressure who are deficient in the mineral, said Jocelyn Edwards<\/a>, Pharm.D, a clinical assistant professor of cardiology at the University of Maryland School of Pharmacy.\u00a0\n<\/p>\n A 2025 review of 38 randomized controlled trials found that magnesium was more effective than a placebo at lowering blood pressure in people with hypertension<\/a> or magnesium-related electrolyte imbalances. Notably, however, there was no statistically significant reduction in those with normal blood pressure or magnesium levels.\u00a0\n<\/p>\n Even for groups that may see greater benefit, experts said there is no one best time to take magnesium. \u201cIn general, magnesium supplements can be taken at any time in the day,\u201d Edwards said.\u00a0 \u201cThe best time of day,\u201d she added, \u201cis ultimately whatever allows the patient to take their medication conveniently and consistently.\u201d\n<\/p>\n There are several potential ways magnesium may affect blood pressure. First, it reduces inflammation. It also helps blood vessels relax and widen by stimulating their inner lining to release prostaglandins and nitric oxide, Edwards said.\u00a0\n<\/p>\n Magnesium also acts as a calcium blocker. \u201cWhen calcium enters the cells of blood vessels, it causes them to constrict, which increases pressure,\u201d Edwards said. \u201cInhibition of this process results in relaxation of the blood vessels and reduction of blood pressure.\u201d<\/p>\n While timing may not play a role in how well magnesium works, other factors can. Certain medications, such as proton pump inhibitors<\/a>, can decrease the absorption of magnesium, as can taking high doses of calcium, zinc, or iron at the same time.\u00a0That’s why it’s best to take these drugs or supplements at least two hours before or after your magnesium supplement, according to experts.\n<\/p>\n It’s also “important to consult with your healthcare provider or pharmacist before starting magnesium if you are on other medications,\u201d Edwards said.\u00a0\n<\/p>\n Meanwhile, some vitamins\u2014namely, D, C, and B6\u2014may improve the absorption of magnesium, Edwards pointed out.\u00a0\n<\/p>\n