Magnesium stearate is among the most polarizing nonmedicinal ingredients employed in the supplement industry. Yet, it keeps appearing on the ingredient decks in the majority of natural health products in capsule or tablet form. Let’s discuss its essential role and whether it genuinely deserves the criticism it receives.

Defining Magnesium Stearate

It’s a simple salt made up of two common nutritional substances, the mineral magnesium bound to stearic fatty acid. Stearic acid is an organic long-chain fatty acid which occurs naturally in chicken, eggs, cheese, salmon, walnuts, almonds, cashews, Brazil nuts, and coconut and palm oils, to name but a few sources. Magnesium ranks among the most critical minerals for virtually every aspect of our health, with good sources being spinach, bananas, beans, and whole grains. Far from being harmful, they’re both beneficial to human health. The good news is that magnesium and its stearic fatty acid component break down within the digestive tract to support energy, metabolism, immunity, and countless biological processes essential for life.

The Role of Magnesium Stearate in Supplements.

Magnesium stearate has a slick texture, which makes it an excellent flow agent when formulating supplements as capsules or tablets. This means that, when added in small quantities, it ensures ingredients mix into a homogenous blend, which ensures consistent dosage. Magnesium stearate is also an anticaking agent, as it improves efficiency by preventing powder from clumping and sticking to production equipment.

Magnesium Stearate: Of Mice and Men

Damaging gossip and publicity have been generated within our industry regarding the potential “dangers” associated with magnesium-stearate consumption. Social-media so-called “warnings” describe the suppression of immune T‑cell function, by means of the erosion of their cell membranes.

These claims are based on a study conducted in 1990 which examined T‑cell function in mice, not humans. In this experiment, T‑cells were isolated, then immersed within a petri dish of stearic fatty acid (not magnesium stearate), an amount exponentially higher than normal dietary intake. This indeed compromised their function.[i] The basic fact which makes this trial irrelevant for human safety is that mice lack the enzyme required to break down stearic acid (not magnesium stearate) to oleic fatty acid, a healthy and beneficial omega‑9 fatty acid. Humans have the delta‑9‑desaturase enzyme responsible for this conversion.[ii] This refutes speculation for potential accumulation within the intestines. When reviewing research studies, it is important to verify that they are applicable to humans, as many studies may specifically involve murine models, which refer to a subfamily in rodent classification, derived from the Latin term murine.

Exploring Safe Consumption Levels

The National Center for Biotechnology Information considers consumption of 2,500 mg per kilogram of body weight safe. This translates to 170,000 mg per day for a 150-pound adult! Supplements typically employ between 0.25 and 5 mg of magnesium stearate per capsule or tablet. Let’s make an extreme approximation regarding consumption: Twenty capsules containing the upper end of magnesium stearate (5 mg per capsule) would still amount to only 100 mg. Typical stearic-acid consumption from all food sources for North American adults is 7,000 mg daily. For example, ½ cup of breastmilk or a small chocolate bar contain 5,000 mg stearic acid.

Magnesium Stearate’s Respected Legacy

Magnesium stearate has a “generally regarded as safe” (or GRAS) status throughout the world. It is accepted for use as a food and supplement additive by Health Canada, the Food and Drug Administration (FDA) in the United States, the European Union, China, Japan, Australia, and New Zealand.

The global wellness economy is expected to soar to 7 trillion dollars U.S. by the year 2025. Magnesium stearate has earned its place to ensure safe, effective, and affordable natural health products worldwide.

To your health!

Gordon Raza, BSc

A graduate in biology from Acadia University, Gord serves as the supplement specialist for Flourish, where he shares his unique perspective on natural health products, nutrition, and active living.