Is magnesium stearate from supplements dangerous?

Magnesium stearate is present in up to 95% of supplements produced by the pharmaceutical industry. However, its effect on health is not really known.

Last update: 01 October, 2022

Magnesium stearate is a chalk-like excipient that used in vitamin supplements and foods to prevent ingredients from clumping together. This improves manufacturing processes and transit through the gastrointestinal tract.

It is useful as an anti-caking agent, emulsifier, release agent, thickener and lubricant.

Even though magnesium stearate has magnesium in its name, is not a source of this nutrient. Is its use harmful to health?

What is magnesium stearate?

Magnesium stearate is a salt that is formed by the union of a magnesium ion with 2 molecules of stearate. Stearate is the anionic form of stearic acid. It has no odor and is insoluble in water, widely used in the pharmaceutical, food and cosmetic industries.

Stearic acid is a saturated fatty acid found in vegetable and animal oils, such as cocoa, coconut oil, red meat, and flaxseed. Despite containing magnesium, its content is very low and it does not really provide the mineral.

Currently, magnesium stearate It is the most used ingredient as an anti-caking agent and lubricant for capsules and tablets.. Its function speeds up the production process in the industry, thus reducing costs and production times.

The pharmaceutical industry uses this compound to speed up its production processes.


Its importance in the pharmaceutical industry

Magnesium stearate is needed only in very small amounts. In addition, it facilitates production, because it prevents drugs from sticking to the machinery. So it is an economical and efficient way to make medicines and supplements.

Besides, in a gastrointestinal tract facilitates transit of capsules and tablets. As an excipient, it can enhance therapeutic effects. In this way, absorption, solubility and consistency are improved.

In addition to its traditional name, it can be found on labels with the following names:

  • magnesium salts.
  • Magnesium salts of fatty acids.
  • Magnesium salts of fatty acids.
  • Octadecanoic acid.
  • E-572.


Health Effects of Magnesium Stearate

According to the US Food and Drug Administration (FDA), magnesium stearate is classified as a safe substance. Therefore, its use as an additive in supplements and foods does not contemplate any risk, as long as it is added in low quantities.

Also, according to the National Center for Biotechnology Information, it is considered safe if consumed in amounts less than 2.5 grams per kilogram per day. Therefore, it is assumed that the small amounts present in the pharmaceutical industry do not have harmful effects.

However, there is a lot of controversy. There are no scientific studies that show in a clear and forceful way its effects.

Effects of magnesium stearate on the immune system

For years it has been believed that magnesium stearate affects the function of T-lymphocytes. The scientific evidence that has been published is a study carried out in 1990 in a single mouse.

In this case, T cells were incubated with stearic acid (not magnesium stearate). Over time, cell membranes collapsed.

But the results cannot be replicated in humans. Mouse T cells do not contain an enzyme capable of converting stearic acid to oleic acid.

May be contaminated with pesticides

Magnesium stearate is obtained from cottonseed oil, so it is believed that it may contain pesticides or come from genetically modified organisms. However, the raw material is purified before being incorporated as an ingredient.

Cottonseed oil is the raw material for magnesium stearate.

Magnesium stearate can be laxative

May have a laxative effect if ingested in excess, because irritates the mucosal lining of the intestine, causing spasms and increased gastrointestinal transit. In very high doses it can damage the skin and be toxic to the liver.

So is magnesium stearate harmful to health?

There is no definitive consensus that demonstrates its harmful effects on health because there does not seem to be enough scientific evidence.

According to the FDA, It is considered that its use as an additive in supplements and foods does not contemplate any risk, provided it is used in small quantities. So there are no harmful effects in the doses of the pharmaceutical industries.

Of course, for the pharmaceutical industry it is key in manufacturing, because it lowers its costs. It also improves digestion and mobilization of pills through the gastrointestinal tract.

That is why, from an economic point of view, industries do not invest in exhaustive studies on the subject. Removing the substance from its ingredients would mean higher manufacturing costs.

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