Is magnesium stearate safe in supplements?

The Food and Drug Administration (FDA) has approved magnesium stearate for use as an additive in food and supplements. According to the National Center for Biotechnology Information, it's considered safe for consumption at amounts below 2,500 milligrams (mg) per kilogram per day.

Is magnesium stearate bad for kidneys?

Magnesium supplements can cause excessive accumulation of magnesium in the blood, especially with patients who have chronic kidney disease. Accumulation of magnesium in the blood can cause muscle weakness, but does not damage the kidney directly.