The Council for Responsible Nutrition has completed an updated evaluation of magnesium safety, raising its recommended safe upper level for supplements to 500 milligrams per day for healthy adults, based on new human clinical data that the organization said shows that higher levels are well tolerated.

The revised supplemental UL—up from the previous 400 mg/day—comes as part of CRN’s ongoing release of updated nutrient safety chapters from its flagship reference book, Vitamin and Mineral Safety (4th edition). The new magnesium chapter is the latest installment in a series of updates to provide industry, practitioners and policymakers with timely access to current science on nutrient safety.

“This updated UL reflects a growing body of evidence that magnesium is well tolerated—even at higher levels than previously recognized,” said Andrea Wong, CRN’s senior vice president, scientific and regulatory affairs. “For formulators of magnesium supplements to support bone, muscle, nerve, or heart health, this offers greater confidence in the safety of levels up to 500 mg/day.”

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Magnesium is one of the top five most used dietary supplements, taken by nearly one in four supplement users (23%) – up from about one in five in 2023, based on CRN survey data. The same survey found magnesium use is especially high among women and older adults and it tends to increase with higher household incomes. 

About 27% of female supplement users take magnesium, compared to 19% of males, and those aged 55 and older report higher usage than younger adults. Consumers cite a variety of reasons for taking magnesium, including helping with relaxation and for better sleep. Overall, these findings highlight magnesium’s growing appeal as a go-to supplement for broad health and wellness benefits, CRN said.