Why Do Some Supplements Contain Fillers and Binders?
You see and hear words like binders, fillers and excipients all the time, but what are they? And are they really necessary? Well, it is my intention to increase your label literacy by defining these and more, so that when you read a label, information can actually be assimilated so you will know what is really in the product and you can then decide for yourself if it is a healthy choice.
The overall term for things that are added that are not a part of the product proper but are things that change a quality of it are called excipients. Other names for excipients are Inactive ingredients, Additives, Base or vehicle, Carrier or Filler.
The term excipient was originally coined regarding drug delivery systems. It comes from ex - out and "cip-" from "capere" to take, and "i" a combining syllable "ent-" a thing that ___. So ironically, the principal name for additional things they put in actually means things that “take out”.
Makes no sense, except that it was thought to be a drug delivery system that would enable the body to “take out” the active ingredient for absorption and use.
There is also the angle that excipient means exception regarding the fact that they are outside of or not part of the actual therapeutic action of the product.
Either way an excipient is everything other than the main active ingredient which is added in to effect some purpose.
Common Excipients:
Binders - make things clump together or stick to something. This is necessary to make pills or granules that don’t break apart. Or sometimes to fix a coating onto the surface of a tablet or caplet. An example of a binder is starch, gelatin or cellulose.
Fillers or Diluents - When there is not enough of an active ingredient to fill up a capsule or to make a conveniently sized tablet or caplet, substances can be added to increase the volume so this can be done. These are called fillers.
If there is not enough of a liquid ingredient to make a convenient dose, an additive to dilute it and make enough volume to amount to, let’s say, a teaspoon, would be called a diluent. It looks like it’s missing a “t” doesn’t it? I checked and although dilutant is a word, it is considered a non-standard form of diluent. Go figure. I don’t ever remember hearing diluent in my whole life. Water is a popular diluent.
Fillers and diluents can also be used to thin out a thing if it is too heavy or viscous.
Lubricants - are used in manufacturing to keep powders from sticking to the machine parts. Like when it is being pressed into tablets.
Glidant or Anti-caking agents - make the powder flow better and not clump.
Disintegrants or Dissolution Agents - facilitate the breakup of capsules or tablets in the gastrointestinal tract, overcoming the binders so that the active ingredient can be absorbed and utilized. These work by either swelling, wicking and thereby fragmenting, changing shape when exposed to water or effervescing. These cause a fragmenting and outward flow which breaks up the pill and disperses it. These agents can also be used to make a powder dissolve more easily in a liquid as well.
Coatings - Protect tablets and caplets from moisture and mask unpleasant tastes.
Preservatives - Prevent oxidation or microbial growth.
The most common excipients I have encountered regarding food supplements are microcrystalline cellulose, stearic acid, magnesium stearate, and Silicon Dioxide, so I think it is important to know what these things are.
Microcrystalline Cellulose is a very common additive. It is a refined wood pulp or plant fiber. It is very versatile in its use. It is used as a binder, a diluent, and a disintegrant depending on the circumstances. It is also used to make capsules when a manufacturer wants to cater to people on vegetarian diets.
All microcrystalline cellulose is not created equally. Environmental factors and the quality of plant it is derived from make a big difference. It could be organic and chemical-free or pesticide-laden GMO corn or cotton or anything in between.
Side effects that have been reported are a laxative effect, a feeling of low energy and headaches. But nothing was reported about the purity of microcrystalline cellulose regarding the complaints.
Gelatin, spelled gelatine in the UK, is used as a thickener and a binder and to make soft gel and hard-shell capsules. Gelatin is a natural protein and very digestible. It nourishes the skin and hair and is related to collagen. It is much more nutritious than microcrystalline cellulose, but it comes from animals and so is not suitable for vegetarians.
Stearic Acid and Magnesium Stearate:
Stearic acid is a saturated fatty acid found in many foods. It is also known as octadecanoic acid because it is 18 carbons long and has a -COOH on one end. COOH is carboxylic acid and “octadeca” means 18 in the international scientific naming system.
It is used in supplement manufacture as a lubricant and a binder. It is the most common binder in making tablets. Magnesium stearate is two stearic acid molecules linked by a magnesium and it is used as a lubricant.
Concern has been raised that too much stearic acid in the diet could coat the intestines and block absorption of nutrients, but others have written on this citing that this opinion was based on one in vitro study (meaning it was in glassware not in the body) and extrapolated to apply to humans. So it was not taken into consideration that in the body certain enzymes can easily turn stearic acid into oleic acid which is the main ingredient of olive oil. Oleic acid is also 18 carbons long, but it is unsaturated (has a double bond) in the 9th position.
These compounds are generally regarded as safe.
Silicon Dioxide (SiO₂) or silica has many different forms. It was fascinating to look into. Its most common form on earth is quartz crystal. I love quartz crystal, but not enough to eat. It makes good jewelry though. Silicon is the largest ingredient in sand. I also love sand, but not to eat.
But here’s where it gets interesting. Have you ever heard of a liquid crystal? That term always confused me because I learned in chemistry that a thing was either a liquid or a solid or a gas. And crystals are solid. How could something be a liquid and a crystal?
Well, there is such a thing. Crystals have rigid lattice structures that are attached to each other and that makes a rigid form. A liquid has nothing attached and components swim around at random. A liquid crystal is kind of a hybrid of the two.
Somehow components are not attached to each other, but they still hang out in about the same pattern. This is called amorphous because it doesn’t have a permanently solid form. The fascinating thing is that even though the form is swimming around it still retains the ability to refract light the same way as a crystal. Oh, that’s how LCD screens work! So finally I know what a liquid crystal is and now you do, too.
The silicon dioxide found naturally in food has this amorphous quality. If you remember, shiitake mushrooms are high in silica. Oats, celery, cucumbers, rice hulls, beets, bell peppers and leafy greens also contain it. It is used by the body to strengthen bones, skin, nails and hair because it is used like a trace mineral and has something to do with collagen production.
In industry they make synthetically amorphous silicon dioxide copying the natural amorphous form and use it to absorb excess moisture in supplements so the ingredients don’t become lumpy and to improve stability and therefore the shelf life by preventing reactive ingredients from reacting and degrading the product. So it is a preservative and anti-caking agent.
But synthetic and nature-made, although they look alike, don’t always act alike because things in nature are synergistic with other things. Plus, the concentrations of the additive far exceed the concentrations in food. And if several products in your supplement routine contain it, it adds up to quite a large amount to be ingesting.
Although silica is generally regarded as safe, a study done in 2024 suggests that prolonged high intake of amorphous silicon dioxide could affect immune cell function and increase gut inflammation.
The best supplements to look for are ones designed by nature and if it isn’t broken, don’t fix it. Additives many times are not really needed. Often you can just eliminate the additive and just shake, stir or chew instead.
Herbal Roots was founded on the purpose of providing the purest products possible. You will not find unnecessary additives or fillers in anything we provide. We strive to bring you the best, always.
So there you have it. I hope this increases your shopping IQ. Happy Label Reading.
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