Dietary Supplement Excipients, Fillers and Binders: What’s Hot and What’s Not?


Transparency is a big issue with consumers these days so it’s no wonder they want to know everything that goes into their dietary supplements, including the excipients, fillers and binders. Lifting the lid on this topic we find a full range of options from the good and the not-so-good.

There’s almost no way around it, most dietary supplements contain some sort of excipients, fillers or binders. Powders have to flow into tablet molds and capsule shells. Active ingredients have to stick together in tablets. And shells for capsules and softgels have to be made out of something. So let’s break it down by looking at some of the most used “other ingredients”.

Dicalcium phosphate is an easy one to start with because you are getting calcium and phosphorus, two essential nutrients, in a well absorbed form – a form that is found in dairy products such as milk and yogurt. It’s often used to bind powders together allowing a tablet to be formed. It’s also used as a filler, for example, when there’s not enough of the active ingredient to make a tab or fill a cap.

Silica is another easy one. It provides tiny “ball bearings” helping powders flow smoothly in the manufacturing process. Silicon is ubiquitous in nature and in foods, especially high fiber foods. It’s necessary for bone growth and maturation, and there is some evidence that it may have an additional benefit of counteracting aluminum. The role of aluminum in human brain pathology is debated, but in preliminary research, silicon has helped to reduce neuronal toxicity of aluminum. (By the way, beer intake was equally effective as silicon in some preliminary research. Cheers!).

Stearic acid and magnesium stearate, (also known as mag stearate), are lubricants made from plant sources. Stearic acid is actually considered a good fat because it does not make blood cholesterol go up, it does not oxidize or go rancid like a lot of fats, and it’s the main fatty acid in chocolate. (If you like chocolate, choose one with cocoa butter, not partially hydrogenated fat). Mag stearate is the combination of stearic acid and magnesium.

There is at least one source which claims that mag stearate and stearic acid are harmful to your T cells, a type of white blood cell that destroys tumor cells. This claim is based on research that may not be relevant to the human body because the T cells were incubated in the lab with stearic acid.

“This claim is based on research that is not relevant to the human body. T cells were incubated with stearic acid in a way that would never happen in real life,” said Gerda Endemann, Ph.D Sr. Research Manger R&D at Threshold Enterprises, Ltd.

Another binder is gum Arabic, or acacia gum, which is sticky and used to bind ingredients together. This natural gum is made from the sap of an acacia tree. Acacia gum is actually sold as a standalone fiber product, because like most fibers, it is considered a healthy food. We don’t digest it, so it helps intestinal flora proliferate.

Maltodextrin is also used as a binder and as a filler. It’s a starch that has been partially broken down. Starches are long chains of glucose and are broken down into medium length chains in maltodextrin. The starch typically comes from corn so there are non-GMO versions of maltodextrin used in dietary supplements.

If you eat 1/10th teaspoon cooked rice, the enzyme amylase in your mouth will start digesting it, and pretty soon you’ll have the equivalent amount of maltodextrin to what you’d get from a supplement pill.

Various kinds of cellulose are also used in supplements typically to help tablets disintegrate. It wicks water into the tablet, expands, and helps the tablet disintegrate in our stomachs. Cellulose is a fiber from plants – we don’t digest it or absorb it so it doesn’t have any calories – like celery or bran.

Most caps are made of gelatin, which is partially hydrolyzed collagen, which is a protein made from bovine or porcine sources. Some people may like gelatin as a source of protein that is probably good for brittle nails. However, the amount in capsules won’t provide enough to make a difference. Others don’t want animal protein, and may prefer veggie caps.

Veggie caps can be made from modified cellulose, which we just talked about, or from carrageenan. Carrageenan is extracted from seaweed, and consists of sulfated polysaccharides. It’s a fiber that has been used in China and Ireland as a thickener for centuries. Claims have been made about carrageenan being undesirable, but according to the research the negative aspects were experienced mostly when injecting it into animals’ paws, not by humans eating it.

There’s almost no way around it, most supplements will contain an excipient, filler and/or a binder. Get to know your supplements, read the labels from top to bottom. Lift the lid. Ask the questions and get the answers until you find the cleanest product for your usage.

Note: a lot of this data was taken from a webinar hosted by Threshold Enterprises, Ltd. with special guest Dr. Gerda Endemann.

The Supplement Issue: Vegetarians and Vegans Julie Dennis has been a lecturer, writer and consultant in the natural products industry for over 20 years. Currently she lectures nationwide discussing health-related topics and intelligent usage of nutraceutical and botanical supplements. She graduated from Dr. Michael Tierra’s East West School of Herbology in 1996, contributed to major natural products industry trade publications, and assisted with editing on books including the American Botanical Council’s Clinical Guide to Herbs, and The Handbook of Clinically Tested Herbal Products, Haworth Press.

EDITOR’S NOTE: The statements presented in this blog should not be considered medical advice or a way to diagnose or treat any disease or illness. Dietary supplements do not treat, cure or prevent any disease. Always seek the advice of a medical professional before adding a dietary supplement to (or removing one from) your daily regimen. WholeFoods Magazine does not endorse any specific brand or product. The opinions expressed in bylined articles are not necessarily those of the publisher.

Posted on WholeFoods Magazine Online, 6/7/2016