Magnesium stearate is often used as a diluent in the manufacture of medical tablets, capsules and powders. In this regard, the substance is also useful, because it has lubricating properties, preventing ingredients from sticking to manufacturing equipment during the compression of chemical powders into solid tablets.
Magnesium stearate is the most commonly used lubricant for tablets. Studies have shown that magnesium stearate may affect the release time of the active ingredients in tablets, but not that it reduces the over-all bioavailability of those ingredients.