The TRUTH about Magnesium stearate: A safe, effective ingredient that adds value to dietary supplements & benefits the consumer

November 26, 2014

If you find you'd like to read something OTHER than Black Friday pre-sale adverts (don't worry, we've got ours, too), then take a look at this post I originally penned for our FB page back in January 2013. Unfortunately Magnesium Stearate is still be maligned by so-called experts who have no science background and/or simply have a different agenda. Feel free to post your comments. 


The TRUTH about Magnesium stearate: A safe, effective ingredient that adds value to dietary supplements and benefits the consumer




Recently Magnesium Stearate, a compound widely used as a manufacturing lubricant in the dietary supplement industry, has come under fire from certain companies, health gurus and self-appointed nutritionists who claim that it is harmful. With scientific references in hand they have impressed laypersons and even mislead some well-known health professionals. Ironically in so doing, these anti-Magnesium Stearate advocates have exhibited their fundamental ignorance of chemistry, biology, the mechanism of human digestion as well as an alarming ability to misconstrue published scientific data.


Given the serious accusation made against Magnesium Stearate (MgSte) we at Intensive Nutrition have decided to comment.  Is the evidence used to support the negative claims based on carefully evaluated clinical studies? Do those studies duplicate the action of Magnesium Stearate as it performs in dietary supplements or are they in vitro exercises that bear little relevance to actual Magnesium Stearate metabolism?


After considerable review it is our position at Intensive Nutrition Inc. that claims made against Magnesium Stearate are patently false. In addition we contend that those who have sought to discredit Magnesium Stearate have done so for reasons other than science, to the detriment of the industry and the consumer. Magnesium Stearate, a chemically inert material, is eminently safe. For over 40 years it has helped dietary supplement companies achieve greater finished product uniformity, allowing for improved product efficacy and value to the consumer.


THE FACTS: Basic, factual information about Magnesium Stearate, Stearic Acid and Magnesium Stearate’s role in dietary supplements


There are a lot of basic misconceptions surrounding Magnesium Stearate from what it is, to the role it plays in dietary supplements to how it is metabolized by the body. Magnesium stearate is essentially a chemically inert, waxy substance, and a salt of Magnesium and Stearic acid. Stearic Acid, a hydrolysate of MgSte, is a very weak fatty acid. It has an 18-carbon long aliphatic straight chain and as it contains no double bond it cannot be hydrogenated or harbor “trans” isomers. This is indisputable chemistry. To repeat, stearic acid is a saturated fatty acid, it is NOT a hydrogenated fat or trans fat and can never become one. 


Many industries utilize MgSte because of its versatility and benign nature. Dietary supplement and pharmaceutical manufacturers extensively employ MgSte as a lubricant in the manufacture of tablets and capsules. The amount of MgSte found in finished products is insignificant. It usually comprises between .2% to .3% of the total unit, which equals .5 mg to 2 mg of MgSte total per tablet or capsule. This translates into even less Stearic Acid per tablet or capsule. An individual, by comparison, regularly consumes significantly more Stearic Acid on a daily basis because Stearic Acid is ubiquitous in food. For example, a single pork chop yields approximately 5000 times as much Stearic Acid (5 grams), 3.52 ounces of yellowtail fish contains 3700 times as much Stearic Acid (3.37 grams), and for those who are vegetarians, one avocado contains 70 times as much Stearic Acid (144 mg) (



What happens to MgSte in the body?


When taken orally, a capsule containing MgSte will disintegrate within 10 to 20 minutes. The capsule will then release its contents into the peptic/HCL emulsifying juices of the stomach. The miniscule amount of MgSte present dissolves and undergoes rapid hydrolysis into Stearic Acid and magnesium chloride. The hydrolysis of MgSte is a well-known and well-understood biological process. It follows the route of lipid metabolism shared by all saturated fatty acids regardless of their origin (animal, vegetable, grain, fruit, or other). Most importantly, hydrolysis of MgSte occurs even for individuals with compromised digestion or low stomach acid levels because an extremely strong acid (HCL) will always destabilize a very weak acid (Stearic Acid).


After hydrolysis, free Stearic Acid proceeds through the lumen where it is transformed in the lumen wall into mono and triglycerides via esterification. It is then further oxidized into oleostearate and then complexed with cholesterol proteins into high-density lipoproteins (HDLs), otherwise known as GOOD fats. Stearic Acid does not contribute to the formation of LDLS (low density lipoproteins) or bad fats. HDLs then enter systemic circulation via the lymphatic system or proceed through the hepatic vein for further metabolism by the liver.


In Summary


  • The amount of Magnesium Stearate in dietary supplements is insignificant.
  • The relevance of Magnesium Stearate to the body is further minimized by the fact that Magnesium Stearate is chemically inert and it is broken down in the stomach. This is true even for those with low stomach acid levels.
  • Contrary to circulating online information, Stearic Acid is a saturated fatty acid NOT a hydrogenated fat and it is impossible for Stearic Acid to become one.
  • The amount of Stearic Acid in each capsule is miniscule. Individuals, including vegetarians and vegans, readily consume at least 10 to 100 times as much Stearic Acid in a single meal on a regular basis.
  • Stearic Acid actually contributes in part to the production of GOOD FATS (HDLs)



Why manufacturers use Magnesium Stearate:  MgSte improves nutrient absorption


Why include Magnesium Stearate in supplements? In addition to ensuring uniform nutrient quantity or 100% conformity to the product label, Magnesium Stearate also exerts a sustained release effect on dietary supplement nutrients. Contrary to what has been reported this sustained release does not hinder absorption. What MgSte does do is ensure that nutrients do not flood nutrient receptors soon after a tablet or capsule disintegrates. This sustained release effect is particularly important for compounds that have complex and time sensitive metabolism like free amino acids. The hydrolysate of MgSte, Stearic Acid, also improves nutrient absorption in dietary supplements. As a lipid proper, Stearic Acid increases the bioavailability of fat-soluble Vitamins like Vitamins A, D and E, and the very popular Coenzyme Q10 (CoQ10).


The addition of MgSte solves potential absorption issues for free amino acid formulas as well as many other nutrients. In conclusion, one can say that MgSte actually aids in absorption and metabolism of dietary supplements.


In Summary


  • MgSte exerts a sustained release effect on dietary supplement nutrients
  • This effect aids absorption
  • Stearic Acid supports greater bioavailability of fat-soluble vitamins and nutrients (CoQ10)




Magnesium Stearate and “Negative” Scientific Studies:  What those studies actually mean


At the crux of the argument against MgSte are a few studies that show how Stearic Acid, the hydrolysate of MgSte, is harmful to cells. Detractors point out that the results clearly correlate Stearic Acid with Tcell death and consequently immunosuppression. While it is true that in these laboratory settings Stearic Acid does prove cytotoxic to Tcells, it is simply wrong and ignorant to conclude that Stearic Acid is toxic to humans under normal circumstances (i.e. when one consumes Stearic Acid in food or from dietary supplements). Why? Well, first of all, in these in vitro, manipulated environments researchers flooded the cell culture with Stearic Acid at an 18:0 concentration. Any time a cell culture environment is bombarded with an external ingredient (let alone at the magnitude of 18:0) cellular malfunction will occur, even when that ingredient is WATER. Second, stearic acid never comes into contact with a cellular environment in the manner or volume these experiments demonstrate; after ingestion Stearic Acid is immediately emulsified and then absorbed by the lumen.


These in vitro studies, therefore, have no relevance to how humans normally process MgSte or Stearic Acid through diet nor were they intended to malign stearic acid. In fact, if one actually reads the earliest of these studies led by researcher P.W. Tebbey (Tebbey), one will conclude that it was performed to investigate if stearic acid had “clinical relevance to allograft situations” not to how stearic acid performs after ingestion. Lastly, one must remember that stearic acid is the most common fat in our diet; it could even be described as ubiquitous. It is found in chicken, eggs, beef, fish, milk and milk products, grains and whole grains and vegetables and is consumed in great amounts even by vegetarians and vegans. If stearic acid were as dangerous as detractors have stated then simply put, one could not survive for very long.




  • Anti-MgSte proponents have misunderstood and misconstrued scientific studies to falsely claim that Stearic Acid is harmful to cells
  • Stearic Acid, the fatty acid consumed in our diet and in dietary supplements is not harmful to cells





There are a few other claims made against MgSte but they do not merit consideration in a rational debate. Based on our own research and over 40 plus years of experience in compounding nutritional supplements we have concluded that MgSte is safe and supports improved nutrient bioavailability and absorption. Critics’ arguments against MgSte are simply wrong and in some instances intentionally misleading.


We support the movement towards more effective and more environmentally friendly manufacturing methods and environments. We take pride in using no chemical solvents, additives or colorants in our products and have had established manufacturing and quality control protocols since our inception in 1968. We do not support, however, maligning a product that is conclusively helpful and question the motives of those who persist in spreading a falsehood.  We do not know why they do it; perhaps they feel it is an effective marketing strategy. Nevertheless, they have almost succeeded in establishing junk science as truth thereby short changing the public.



Olivia B. Melaugh, CIO

Intensive Nutrition Incorporated



Works Cited:


  1. ND. Ministry of Education, Culture, Sports, Science and Technology of Japan. Web. 10/01/12.

2.  Tebbey PW, Buttke, TM. “Molecular basis for the immunosuppressive action of stearic acid on T cells.” Immunology. 1990 October; 71(2): 306.


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