Magnesium stearate is a compound consisting of the mineral magnesium and the saturated fat stearic acid that is sometimes used in making medications and supplements. It is a white powder that helps keep the ingredients in these pharmaceuticals flowing smoothly through the machinery during production. This helps ensure a consistent dose winds up in each tablet. If you'd like to avoid this inactive ingredient, there are supplements available that come in different forms or use a different inactive ingredient for the same purpose.
What to Look For
Supplements in forms that aren't based on powders, such as liquid or gummy supplements, typically don't contain magnesium stearate. Substances called glycerin fatty acid esters can serve the same purpose, so not all vitamins in tablet form contain magnesium stearate. If you're purchasing a vitamin in powder, tablet or capsule form, check the "inactive ingredients" or "other ingredients" section of the label to see whether magnesium stearate is included.