Is Magnesium Stearate Harmful In Supplements?

Magnesium stearate is found in some dietary supplements. It is often said that it is harmful and that it should be avoided as a matter of urgency, as it prevents the absorption of the corresponding vital substances. Is that really the case? Or is magnesium stearate not a problem?

Magnesium stearate: That’s why it’s said to be harmful

Magnesium stearate is added to some dietary supplements, not as a source of magnesium, but as an additive. Because the compound would not even be suitable as a source of magnesium, as it only consists of 4 percent magnesium, the rest, i.e. 96 percent, consists of fatty acid stearic acid.

It is now repeatedly claimed that magnesium stearate is harmful for various reasons, which is why you should never take any dietary supplements that contain this substance. The allegations are as follows:

• Magnesium stearate harms the immune system.
• Magnesium stearate prevents the active ingredients of the corresponding food supplements from being able to be absorbed in the intestine at all.
• Magnesium stearate forms a harmful (slimy) biofilm in the intestine.
• Magnesium stearate is made from genetically modified raw materials (cottonseed oil) and can be contaminated with pesticides.
• Magnesium stearate can trigger allergies.
• Magnesium stearate is toxic.

Are all of these claims true? First, let’s clarify what magnesium stearate is and what properties it has.

What is magnesium stearate?

Magnesium stearate is a compound of magnesium and stearic acid. Stearic acid, on the other hand, is a long-chain saturated fatty acid also found in beef, cocoa butter, and coconut oil. It is considered the only long-chain saturated fatty acid that, even according to official opinion, should not increase cholesterol levels or the risk of cardiovascular disease.

Magnesium stearate can perform various tasks and is therefore referred to as a filler, binder, carrier, or mixing agent depending on the area of ​​application – for example in the manufacture of tablets, capsules, and powders. In its function as a mixing agent, the salt ensures the correct mixing ratio of the individual raw materials in medicines and food supplements.

The food industry uses magnesium stearate as an emulsifier, foaming agent, or release agent. And in cosmetics, it is used as a humectant, colorant (white), or anti-caking agent.

However, magnesium stearate can also be used to protect production machines, as it lubricates them and prevents them from sticking. It is therefore often said that the production of magnesium stearate-free food supplements is more complex and expensive and indicates higher quality preparations, while products with magnesium stearate are almost described as cheap mass-produced goods.

How is magnesium stearate declared?

Other names for magnesium stearate are “magnesium salt of fatty acids” (although this can also mean other fatty acids) or E470b. Cosmetic items say “Magnesium Stearate”.

Now let’s look at the individual allegations made against magnesium stearate and see if they are true or not. Always keep in mind that the amount of magnesium stearate used in supplements is minimal. On the whole, this is no more than 1 percent of the capsule content:

• Does magnesium stearate damage the immune system?

Magnesium stearate is said to have a negative effect on the immune system and to a certain extent suppress it, it is sometimes argued. A study from 1990, which was carried out with stearic acid but not with magnesium stearate – and also with isolated mouse cells, is considered proof.

The T and B cells (immune cells) of the mice were bathed in stearic acid (and other components) in a petri dish and the T cells were observed to incorporate the stearic acid into their cell membrane. This led to an unstable cell membrane and the cells died.

Since stearic acid was used but not magnesium stearate, the study could be used against foods that contain stearic acid (beef, chocolate, coconut oil) but not against magnesium stearate, especially since magnesium stearate is not eaten nearly as much as one food. Coconut oil contains only 1 to 3 percent stearic acid, while beef fat contains around 12 percent.

In real life, however, our cells are not “bathed” in stearic acid even when we include coconut oil or cocoa butter in our diet, so the study or its results cannot be applied to real events.

In this case, mouse cells also react differently than human T cells. The former can’t desaturate (desaturate) saturated fat, but human T cells can, so even if you bathed them in stearic acid, they could maintain their healthy functions.

• Can magnesium stearate inhibit the absorption of active ingredients?

It is often said that magnesium stearate ensures that the body cannot absorb the active ingredients taken from the dietary supplement. Magnesium stearate, therefore, worsens the bioavailability of dietary supplements.

And indeed, in 2007 in vitro study, tablets with magnesium stearate were shown to dissolve more slowly in artificial gastric acid than tablets without magnesium stearate.

However, an earlier study had already shown that the increased dissolution time had no effect on the bioavailability, which could be demonstrated in the test persons’ blood, where a reliable level of the corresponding active ingredient could be determined. Another study even showed that magnesium stearate does not affect the dissolving time of tablets, from which one could conclude that the dissolving time also depends on the active ingredient.

But even if magnesium stearate should increase the dissolution time, this has no negative effects, since sooner or later the active ingredient will still reach the blood completely. In addition, slow absorption is often desirable so that the active substance reaches the blood continuously and short-term peaks are avoided.

• Does magnesium stearate form a harmful biofilm in the intestine?

Another accusation against magnesium stearate is that a harmful biofilm develops on the intestinal mucosa under its influence. A biofilm consists of bacterial colonies that attach themselves firmly to a surface (here the intestinal mucosa) and surround or protect themselves with mucus that is difficult to remove. One knows such biofilms z. B. from drainpipes, but also dental plaque is such a biofilm.

The biofilm statement probably comes from the fact that soap scum contains magnesium and calcium stearate and contributes to deposits and biofilms in the drain. So it is believed that such a film can also develop from magnesium stearate in the intestine.

However, it should be clear that, first of all, the gut of a living being is very different from a relatively dead drain, and also that the amount of magnesium stearate in a capsule is significantly less than what shower gels and soaps end up in the drain every day.

Of course, there are still biofilms in the intestines, but they develop as a result of an overall unfavorable diet and lifestyle, including medication, etc. B. regularly takes a capsule with intestinal cleansing zeolite, which i.a. also contains some magnesium stearate, then the zeolite is more likely to lead to the breakdown of the biofilm than the magnesium stearate it contains could contribute to the build-up of the same.

Does Magnesium Stearate Contain Pesticides? Is it made from genetically modified raw materials?
Another criticism is that magnesium stearate may be genetically modified and/or contaminated with pesticides, as it is often made from cottonseed oil, which can be both.

The magnesium stearate can actually come from genetically modified raw materials, which one would have to ask the manufacturer about since there are usually also non-genetically modified versions on the market so manufacturers would have to have a choice here.

Since magnesium stearate is an isolated, refined, and highly purified substance, i.e. it contains no other components of cottonseed oil (or other possible oils of origin), it can be assumed that no pesticides found their way into magnesium stearate or dietary supplements. And even if that were the case, the amounts would be so small that they would hardly be relevant. Here the pesticide contamination of the main ingredients of the dietary supplements would really be more important to check.

• Can magnesium stearate cause an allergy?

A 2012 study called it “magnesium stearate: an underestimated allergen” (9). It was reported on a 28-year-old woman who was allergic to magnesium stearate. However, everyone knows that individual case reports are hardly suitable for making statements about the effect of a substance on the general public.

Of course, individual intolerances are always possible – and should allergic reactions occur, then of course we will immediately try to find the cause. However, magnesium stearate – which is known to consist of just magnesium and fatty acid – will rarely be the trigger.

• Is magnesium stearate toxic?

If one wanted to poison oneself with magnesium stearate, this would not be possible with dietary supplements containing magnesium stearate. You would have to consume 2.5 g of pure magnesium stearate per kilogram of body weight, i.e. 175 g if you were e.g. B. would weigh 70 kg to experience acute discomfort from a magnesium stearate overdose.

However, a capsule with a dietary supplement contains completely different amounts, namely – as in the example of these zeolite capsules – only 6 mg per capsule.

Conclusion: Can you take magnesium stearate supplements?

Yes, you can, as the above data shows. However, dietary supplements containing magnesium stearate often contain many other unnecessary additives, some of which may actually be of concern. We would therefore always resort to dietary supplements that do not contain these additives and therefore also without magnesium stearate. However, if there were to be a product with only magnesium stearate, then taking it would probably not pose a health risk.