The Dirty on Magnesium Stearate

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The Pure TheraPro Team

The Pure TheraPro Education Team is comprised of researchers from diverse backgrounds including nutrition, functional medicine, fitness, supplement formulation & food science. All articles have been reviewed for content, accuracy, and compliance by a holistic integrative nutritionist certified by an accredited institution.
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Magnesium stearate is not an essential mineral form of magnesium, in spite of its deceptive name. Magnesium stearate is a simple salt created when magnesium ions bond to stearic acid, which is a fatty acid. The result is actually a lubricant used in over 95% of supplements for manufacturing purposes. Magnesium stearate prevents capsules and tablets from sticking to one another and to machinery during production.

Additives such as fillers, binders, flow agents and excipients are commonly used in the supplement industry as they facilitate the manufacturing process and also improve profit margins.  


Recent studies are questioning the safety of magnesium stearate. Here are some of the potential effects and risks:

1. According to a 1990 study, stearic acid causes the collapse of cell membrane integrity. Stearic acid was shown to suppress the action of T-cells, a key component of the immune system. Because magnesium stearate is in so many supplements, if you are taking a variety containing this excipient, it may pose a risk to your health. The study indicates that “high amounts of magnesium stearate act as an immunosuppressor.” But what exactly is considered high amounts? Everyone’s toxic load has an individual limit. Prolonged use over years may increase this toxic load and have detrimental health effects in people with immune system and detoxification issues, such as MTHFR. More studies are necessary to better understand the effects on immune function.

2. Magnesium stearate decreases the absorption rates of tablets and capsules, reducing the efficacy of your supplements. Because it coats the tablet or capsule, your digestive enzymes must break down the magnesium stearate first in order to receive the nutrients/vitamins in the tablet or capsule. This reduces the absorption rate. A study demonstrates that stearates reduce the dissolution rate of capsules by 65%, which may affect where the nutrients are dissolved in your digestive tract, impacting absorption rates. This is most concerning to individuals with already- existing digestive issues that impair nutrient absorption, such as Leaky Gut Syndrome, SIBO, Crohns, Ulcerative Colitis and other gut issues. Magnesium stearate may also irritate the bowel mucosal lining, causing digestive issues, such as chronic diarrhea.  

3. Ingredients utilized to create magnesium stearate are made with highly toxic oils, such as hydrogenated cottonseed and palm oil, which are frequently genetically engineered. These possess the highest content of pesticide residues of all commercial oils since cotton crops are heavily sprayed. The high heat and pressure used in the hydrogenation process combined with the presence of a metal catalyst negatively alters the molecules and may contaminate the stearates produced.

Although the concerns about magnesium stearate are not shared by everyone in the supplement and holistic health community, enough evidence exists to raise an eyebrow.

It’s interesting that companies that manufacture and transport magnesium stearate must file a Material Safety Data Sheet with the Environmental Protection Agency because magnesium stearate is considered a “hazardous substance.” Magnesium stearate uses are also vast and disturbing when you think that they are listed as safe for consumption: ammunition, paint and varnish drier, binder, emulsifier, dusting powder to name a few.

Magnesium stearate is not an essential substance in manufacturing supplements, although eliminating it increases costs for supplement companies and affects their bottom line. Read labels, be your own advocate and seek out supplement companies that put your health top of mind over their profit margins.

Rest assured that at Pure TheraPro Rx, purity is our priority. You will not find magnesium stearate or any other fillers, flow agents or excipients in our products. What is on the label is in the bottle with complete transparency.

All of our products are third party laboratory tested post-production for heavy metals and other contaminants. We are also cGMP Certified (Current Good Manufacturing Process) with strict FDA compliance. These are just a few of the measures we undergo to ensure the consistent quality and potency of our formulas.

In addition, our production facility and formulas have physician and scientist oversight. All products are made in the USA; no raw materials are from China. Unlike most other supplement companies, the ingredients that go into our supplements are not selected based on cost. Instead, they are selected based on purity (to ensure contaminants such as microbes and heavy metals comply with regulatory GMP requirements), potency, and chosen based on successful scientific research. Patented ingredients are utilized when appropriate.

The typical company is forced to buy raw materials as cheap as possible to account for the following items:

1) supply/manufacturing costs
2) overhead costs
3) marketing costs
4) wholesale profit margin selling to retailers / doctors / clinics

We chose a different route—direct to you. As a result, we are able to bring you the best possible quality at the lowest possible price. We are the manufacturer and retailer, resulting in greater efficiencies.

If purity is your priority, check out our product line.