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What / Who is RetzlerRX™?

Founded by Dr. Kathryn Retzler, RetzlerRX and HormoneSynergy® Clinic LLC is a private membership (concierge), age management and functional medicine clinic (also known as "anti-aging medicine"). We focus on the underlying causes of aging and disease, integrating evidence-based therapies and recommendations based on physiology (how the body works).  We provide the most advanced treatments for slowing the effects of aging and cognitive decline, while restoring health and vitality with the use of natural therapies, lifestyle recommendations, bioidentical hormones, pharmaceutical grade supplements, medication if and when necessary and individualized treatment plans.

What should I consider when purchasing supplements?

It’s important to keep in mind that not all products are alike, no matter what the label or packaging may claim. Make sure the supplements you take are manufactured in facilities that have pharmaceutical certification or are certified for good manufacturing practices (GMP) by the NPA (Natural Products Association), TGA (Therapeutic Goods Administration of Australia). Note: there is a difference between GMP compliance and GMP certification. GMP compliance means the company monitors itself for adherence to GMP standards. GMP certification means an independent organization monitors the company for GMP standards. It’s very expensive to become GMP certified; however, this certification ensures that the products you use are of exceptional quality.

Besides coming from GMP-certified companies, ideally the supplements you take should be scientifically evaluated to verify the presence and concentration of active constituents. Very few supplement manufacturers conduct clinical trials on their formulas to document safety and effectiveness. This is because research is very expensive to perform. However, purchasing supplements with documented safety and effectiveness is a reliable investment in your health. In addition to quality assurance and evaluation via clinical trials, look for optimal forms of nutrients and dosages.

Consider the supplements you take to be as important as any medications prescribed by your doctor; in fact, you may consider them to be more important than medications since they can help you prevent the “polypharmacy” that is standard of care for aging Americans (remember, 25% of all Medicare patients use 6 or more drugs every day).

What's all the fuss about Magnesium Stearate / Stearic Acid?

A few companies and some alternative health “professionals” have whipped up pointless concern over the inert flowing agent used in dietary supplements known as magnesium stearate. In each case the motivation appears to be one of promoting their own products - "Free of Magnesium Stearate" - as having some benefit over products containing it.

Let's look at the facts.

Magnesium stearate is a simple salt made of two common nutritional substances, the mineral magnesium and the saturated fat stearic acid. It is used as a “flow agent” in many nutritional supplements and pharmaceuticals. Magnesium stearate contains two molecules of stearic acid and one molecule of magnesium. The molecule is held together by ionic bonds — the definition of a salt — that break apart easily in acid, the condition found in the human stomach.

Though the name may make it sound like a synthetic, space-age toxic molecule, both magnesium and stearic acid are abundantly available in many foods in our diet.
Consider these facts:

  • The daily adult intake of stearic acid from food (US adult) averages about 7,000 mg/day.
  • A person taking 20 vitamin capsules weighing 500 mg each and containing 1% magnesium stearate would take in less than 96 mg of stearic acid per day. Manufacturers typically use 0.25% – 5% magnesium stearate in nutritional formulations.
  • The amount of stearic acid from supplements in the above scenario is 1.3% of the total daily adult intake.
  • Four ounces of human breast milk contains more than 5,000 mg of stearic acid. A 2-ounce chocolate bar will also provide well over 5,000 mg of stearic acid.
  • Magnesium stearate is considered safe for human consumption at levels below 2,500 mg/kg per day. This equates to 170,000 mg per day as a safe dose for a 150-pound adult. That’s almost 6 ounces of pure magnesium stearate.

Magnesium is an essential mineral, the major mineral most likely to be deficient in the American diet. Stearic acid is a saturated fatty acid found in many foods including eggs, chicken, grass-fed beef, coconut oil, walnuts, cheese, chocolate, salmon and human breast milk, to name just a few. Both magnesium and stearic acid are not only safe, they are beneficial to human health. Magnesium stearate is simply a salt that combines both of these molecules.

The use of magnesium stearate in dietary supplements is very safe and is an effective way to help produce quality dietary supplements by preventing clumping and ensures strict quality control, and guarantees. There is simply no known risk or technical reason not to use magnesium stearate in small and appropriate amounts during the production of dietary supplements. To the contrary, when used properly magnesium stearate assists in making a uniform and better quality product.

This has been proven by decades of use in the dietary supplement industry and health benefit by millions of consumers. Critics most often point to one rat study and a T-cell study, neither of which have any relevance whatsoever to human consumption of magnesium stearate / stearic acid. As a matter of fact, in the rat study, magnesium stearate was only shown to be harmful where the rats were force-fed such as exorbitant amount that no human on the planet could ever consume that much.

Companies not using the industry standard magnesium stearate may be hard pressed to prove that their vitamin capsules or tablets have a consistent dose. The FDA will be looking into this issue as part of their cGMP guidelines—as the quality and consistency of fill and legality of label claims will come front and center for companies that are not making products in ways that are understood to be good manufacturing practice. Right now, many of these companies say whatever they want and don’t have to prove anything - times are changing.

There is simply no known risk or technical reason not to use magnesium stearate in small and appropriate amounts during the production of dietary supplements. To the contrary, when used properly magnesium stearate assists in making a uniform and better quality product.