Magnesium stearate is the magnesium salt of the fatty acid stearic acid (figure 1). It has been used in the food industry for decades as an emulsifier, binder and thickener as well as an anticaking agent, lubricant, release agent and defoamer.

Everything You Should Know About Magnesium Stearate

What is Magnesium Stearate?

Have you ever wondered what the coating is on your medicines and vitamins? It is an additive made from magnesium stearate.

Magnesium stearate is a fine white powder that clings to the skin and feels greasy to the touch. It's a simple salt made up of two substances, a saturated fat called stearic acid and the mineral magnesium. Stearic acid is also found in many foods, such as:

Magnesium stearate is commonly added to many foods, drugs and cosmetics. In medicines and vitamins, its main purpose is to act as a lubricant.

What does magnesium stearate do?

Magnesium stearate is an additive mainly used in pharmaceutical capsules. It is considered a "flow agent". It prevents the various ingredients in the capsule from sticking to each other and the machinery that makes the capsules. It helps to improve the consistency and quality control of pharmaceutical capsules.

It is possible to manufacture drug capsules without magnesium stearate, but it is more difficult to guarantee the consistency and quality of these capsules. Magnesium stearate is used to delay the breakdown and absorption of medications so they are absorbed in the correct area of the intestine.

What are the health risks of magnesium stearate?

Magnesium stearate is generally considered safe for consumption. It can have a laxative effect if taken in excess. It irritates the mucous lining of the gut. This can cause your bowels to spasm, causing bowel movements and even diarrhea.