Magnesium stearate

The controversial ingredient in every tablet

Magnesium stearate is one of the most common additives used in the production of food supplements. You can find it in all kinds of food supplement tablets, capsules, powders from multivitamins, digestive enzymes to products for joints and even for hair loss. It is very difficult to find a dietary supplement that does not contain magnesium stearate (1).

As in the many areas of medicine, there are hundreds of gray zones instead of white or black zones, and in recent years magnesium stearate has become a controversial debate among some nutritionists, pharmacists and experts in health area. 

What is magnesium stearate?

Magnesium stearate is used as a filler which allows raw materials to be mixed without agglomeration. It also allows the machines to work at high pressure without overheating, that’s why it is used as a lubricant since it is composed of 90% fatty acid and only 5% magnesium (2). 

When magnesium stearate is added, raw materials mix evenly. This is how the pharmaceutical and health food companies make sure that each tablet or capsule is uniform, with exact quantity of active ingredients (3). Its composition is made of two molecules of a fatty acid called stearic acid and a magnesium ion. 





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Is magnesium stearate really safe?

I will try to be as objective as possible avoiding the extreme opinions that are commonly found on the internet. 

Currently there is not enough medical information or scientific studies that can ensure that stearate is a completely safe additive, or on the contrary, whether it is unhealthy and has it negative side effects for health. 

But please think about that: how many scientific studies have shown that some additive is safe, and decades later it has been associated with cellular alterations or autoimmune diseases? Can this be the case of magnesium stearate? Only time can show.

Good judgment is the key


Obviously, the extremes are never good, and it is important to make careful decision what kind of supplementation to take.

You may have some food supplements that already contain magnesium stearate and you may think of stopping of consuming them. But in the other hand amount of magnesium stearate in food supplements is usually relatively low.

Of course, the decision is personal, but as a precaution you can always buy supplements that do not contain magnesium stearate. In fact, companies that don’t use magnesium stearate, show that they undoubtedly work in favor of quality and security of their products.

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Some studies about stearate

One of the most important function of the immune system to fight antigens is the production of T cells, since they are responsible for detecting and eliminating pathogenic micro-organisms. The journal Immunology published already in 1990 says that T cells can be affected in the presence of steric acid (main component of magnesium stearate). The study says that the response of T cells was inhibited. (4)

It has been also reported that magnesium stearate may affect the speed at which capsules or tablets dissolve in the gastrointestinal tract. Another study revealed that the presence of steric acid can affect the absorption of nutrients in the gastrointestinal tract by inhibiting the autoinducer-2 (AL-2) molecules that are used by micro-organisms to modulate different biochemical processes. (4)

Allergies or hypersensitivity to magnesium stearate are not so common even though there are many comments on blogs from people who claim to have had allergic reactions and joint pains. One published study showed a patient who has suffered an urticaria because of the magnesium stearate. But we must recognize that it is not so common, even though it can happen. (5,6)


One of the main sources of stearate acid is cotton seed or palm oil. In recent years, we were warned about cotton seed oil because it can be a GMO product since it can be rich in pesticides. Although many say that the final product should not be contaminated, the truth is that it does not always meet the strictest quality standards.



Unfortunately, the debate on whether magnesium stearate should be used or not, isn’t clear. But never forget that, as often happens in medicine, there are a number of conflicts in gray zones and the lack of studies is not an indication that good is bad and bad is good. 


In Aarja Health we have invested in technology in order to avoid using magnesium stearate in our products. We ensure every process, from the selection of raw materials with high quality standards and own production to final destination to our customers.

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