Magnesium Stearate: What is it? Is it Safe to Consume?

Magnesium Stearate What is it Is it Safe to Consume

What is Magnesium Stearate?

Magnesium stearate is a salt that is produced when a magnesium ion bonds with two stearate molecules.

Stearate is just the anion form of stearic acid, which you’ve most likely heard of before.

Stearic acid is a long-chain saturated fat that is abundant in beef, cocoa butter, coconut oil, and other natural foods.

It’s also the only long-chain saturated fat that scientists and medical practitioners agree doesn’t raise cholesterol levels, and doesn’t increase risk of heart disease.

Magnesium stearate is most commonly used in supplement manufacturing as a ‘flow agent,’ which helps ensure that the equipment runs smoothly and the ingredients stay blended together in the correct proportions.

Given the seemingly benign components of this additive, it’s a little surprising how controversial it is.

There are a lot of misconceptions and inaccurate statements about it floating around the internet.

And while I wouldn’t recommend consuming vats of the stuff (not that you’d want to). I think the concern over magnesium stearate is largely overblown.

But lets look at some potentially harmful effects…

Potentially Harmful Effects of Magnesium Stearate

Magnesium stearate is formed by adding a magnesium ion to stearic acid.

The compound has lubricating properties, which is why it’s often used in the making of supplements.

As it allows the machinery to run faster and smoother, and prevents the pills or capsules from sticking to each other.

However, previous research has shown that stearic acid suppresses T cells—your natural killer cells—which are a key component of your immune system.

According to that study, stearic acid causes the collapse of cell membrane integrity—an effect that was found to be time and dose dependent—which, ultimately, can destroy cell function.

In my view, if you’re taking a supplement, making sure it’s a high quality.

Natural food-based supplement that does not include potentially harmful fillers and additives such as magnesium stearate.

Contamination Issues

Another issue that has been raised in relation to magnesium stearate is the fact that the stearate is commonly sourced from hydrogenated oils such as cottonseed oil.

This crop is oftentimes genetically engineered.

But even when it’s not, cottonseed oil tends to have very high levels of pesticide residues.

Other contamination can also occur during the manufacturing process of the magnesium stearate.

According to a December 2011 report by the World Health Organization (WHO)2.

Several batches of magnesium stearate manufactured by Ferro Corporation were found to contain various levels of harmful contaminants such as:

  • Calcium hydroxide: aka “slaked lime,” which is considered toxic, according to the National Institutes of Health
  • Bisphenol-A: a toxic chemical and potent endocrine disrupter
  • Irganox 1010: a “moderately hazardous” chemical with potential developmental toxicity, according to the Environmental Protection Agency3


The cross contamination was determined to be due to incomplete cleaning of air milling equipment introduced into the Ohio Ferro plant in February that same year.

Granted, this is not a chronic problem, as far as I know, but it just goes to show how easily contamination can occur in general.

Will Magnesium Stearate Get Axed?

As recently explained in the featured article, magnesium stearate might be on the verge of getting axed from supplements altogether.

Which probably would not be a bad thing; at least from a health perspective.

During the March 2010 session of the Codex Committee on Food Additives (CCFA), it was recommended that “magnesium salts of fatty acids” (ie magnesium stearate) be deleted from the Codex, as it has no known use in food.

The following year, at the March 2011 CCFA session, the International Alliance of Dietary Supplement Associations (IADSA) submitted a request to reinstate magnesium stearate as a food additive. It was subsequently reinstated under INS number 470(iii).

However, as explained in the featured article:

“…the Joint Expert Committee on Food Additives (JECFA) now requires toxicity data to substantiate magnesium stearate’s new standing, despite its existing history of use in supplements. According to John Venardos, senior vice president of regulatory affairs for the global network marketing company Herbalife, who presented this issue at the recent NIA West conference in Laguna Beach, the estimated cost of this tox data on magnesium stearate would cost $180,000. No manufacturer has yet volunteered to foot the bill.”

It would appear as though, unless someone accepts the task of doing the research necessary to prove its safety as a food additive. It will likely get eliminated from the market.

Considering the fact that a vast majority of supplement makers use magnesium stearate, backlash is to be expected.

But for companies that already operate without this. It’s just proof that they’ve been right all along.

Eliminating this component from the product equates to slightly higher manufacturing costs.

As the machines cannot run as fast and hence cannot produce as much on any given day.

But I believe the increase in cost is well worth it.

It’s really important to me to first do no harm, and to take the extra precautions to ensure the products sold on this site are of the highest quality and purity possible.

How much is safe to consume?

The U.S. Food and Drug Administration (FDA) has approved magnesium stearate for use as an additive in food and supplements.

According to the National Center for Biotechnology Information, it’s considered safe for consumption at amounts below 2,500 milligrams (mg) per kilogram per day.

For a 150-pound adult, that equals 170,000 mg per day.

Capsule and medication manufacturers typically only use small amounts of magnesium stearate in their products.

When you take their products at the recommended dose, they don’t contain enough magnesium stearate to cause negative side effects.