Magnesium stearate is a very fine, light white, precipitated or milled, impalpable powder of low bulk density, having a faint odor of stearic acid and a characteristic taste. It mainly consists of variable proportions of magnesium stearate and magnesium palmitate obtained from vegetable sources.
Magnesium stearate increases the time it takes for tablets and capsules to dissolve due to the film it forms on capsule or tablet ingredients. Magnesium stearate coats a good portion of the molecules in a tablet or capsule, requiring digestive enzymes to break down the magnesium stearate coating before being able to access the nutrients it envelops.