Thorne has been recognized since 1984 for its high standards, quality, and purity. Part of that recognition derives from not using unnecessary ingredients like the fillers, additives, and other excipients that are ubiquitous in the nutritional supplement industry.

These are the substances that other manufacturers use to decrease production time and maximize productivity, regardless of an excipient’s impact on absorption or health. 

At Thorne, we refuse to include unnecessary excipients that can interfere with a product’s dissolution and absorption or otherwise detract from the optimum health of the user.

Thorne maintains a running list of more than 35 substances that will never be included in our products – our well-known “No List.”

Thorne’s “No List” includes artificial sweeteners, artificial flavors, chemical preservatives, hydrogenated oils, high fructose corn syrup, colorants, large fatty acids like stearic acid and magnesium stearate, sulfites, BPA, plasticizers, irradiated ingredients, gluten, eggs, and nut-derived ingredients.

We consider all of these ingredients to be unnecessary and potentially problematic, and we will never use them.

However, because Thorne does use various inactive ingredients to manufacture our high-quality product line, we think it’s important that you know that the ingredients listed in the “Other Ingredients” portion of our product labels do not detract from health, absorption, or a product’s function.

Fillers 101 – What are these “Other Ingredients” used for?

Most nutritional supplements contain some forms of excipients – including fillers, flavor enhancers, or manufacturing agents like binders or lubricants – that contribute functional or structural properties.

For example:

  • Flowing agents and lubricants make manufacturing faster and more efficient by ensuring ingredients won’t clump together or stick to manufacturing equipment.
  • Preservatives protect from microbial growth and product degradation and, in so doing, extend the life of a supplement.
  • Colorants maintain consistency and enhance appearance.
  • Fillers contribute volume so capsules don’t appear to only be partially filled when there is not enough active ingredient volume to fill the capsule.
  • Binders hold ingredients together, and so are more often used in tablets than capsules. 
  • Sweeteners and flavorings improve taste and palatability.

Unfortunately, although individuals choose a supplement in hopes of improving their health, not all of the “Other Ingredients” in a supplement are totally benign. 

For example, stearic acid/magnesium stearate, generally used as a lubricant, can interfere with dissolution and consequently absorption.

Although many health-care professionals recommend the avoidance of sucralose, acesulfame K, high fructose corn syrup, and sugar, it’s not uncommon to find these ingredients in protein powders, powdered mineral supplements, and electrolyte replacement supplements.

Instead of high fructose corn syrup and artificial sweeteners, Thorne uses monk fruit, stevia, and occasionally evaporated cane juice sugar to lend a sweet taste to powdered products.

Rather than using noxious preservatives, Thorne uses mixed tocopherols, rosemary extract, or citric acid to prevent rancidity or microbial contamination. 

Instead of artificial flavoring agents and synthetic imitation vanilla, our vanilla and other flavors are derived from natural sources that present little risk of reactivity.

Still, people want to know just what Thorne’s “Other Ingredients” are and why they are used. Here’s the rundown on the most common “Other Ingredients” you’ll see on a Thorne product label.

1. Calcium laurate

Made from the mineral calcium and lauric acid. Lauric acid is a medium-length fatty acid found in coconut milk and breast milk (it comprises about six percent of the fat content of breast milk). Calcium laurate helps powders flow into capsules and holds those powders together. 

2. Calcium, magnesium, and potassium citrate

Natural mineral chelates used to regulate acidity and to emulsify or stabilize a formula.

3. Citric acid 

A weak organic acid that is used to preserve or stabilize a formula, enhance flavor, and regulate acidity. It is also used in making Thorne’s chelated mineral formulas, such as Magnesium Citramate.

4. Leucine

A naturally derived essential amino acid that helps powdered ingredients flow through manufacturing equipment and into capsules. 

5. Maltodextrin

Holds ingredients together during manufacturing, as well as providing a base for a formula. Instead of using maltodextrin made from genetically modified corn, Thorne uses gluten-free, hypoallergenic maltodextrin derived from tapioca and cassava.

Although maltodextrin can have a high glycemic index when used in a large amount, there is not enough in a Thorne formula to affect blood sugars. And, in fact, maltodextrin is used in only two Thorne products.

6. Time-Sorb®

High- and low-viscosity hydroxypropyl methylcellulose complexed with magnesium citrate laurate is used instead of plasticizers, magnesium stearate, and waxes to provide for the delayed release of the active ingredient and to protect the active ingredient during passage through the harsh conditions of the stomach.

7. Hypromellose

Also known as hydroxypropyl methylcellulose (HPMC), is used to make our vegetarian capsules. Most of the HPMC used to make our vegetarian capsules is naturally derived from wood pulp. In addition, Thorne’s vegetarian capsules are organic compliant, non-GMO, Kosher and Halal certified, vegan, and hypoallergenic.

8. Medium chain triglycerides (MCTs)

A type of fatty acid found in several foods like coconut and dairy products. MCTs are used as carriers to help powders efficiently flow through manufacturing equipment and to enhance solubility. The MCTs Thorne uses are derived from coconut or palm oil. The palm-derived MCT oil in Thorne products is certified by the Roundtable on Sustainable Palm Oil (RSPO) to be sustainably harvested.

9. Microcrystalline cellulose (MCC)

Used to fill space in a capsule when the active ingredients in the formula can’t do that alone. MCC is also used to prevent clumping and to help ingredients flow through manufacturing equipment. Like HPMC, Thorne’s MCC is derived from wood pulp and is hypoallergenic, non-GMO, Halal and Kosher certified, and much cleaner than the starches and sugars such as lactose that are often used as fillers by other manufacturers. 

10. Silicon dioxide

Also known as silica, is a naturally-occurring compound that contains silicon, a mineral that is ubiquitous in nature and found in many foods, especially those high in fiber, and, because it is necessary for bone growth and maturation, it is also often added to nutritional supplements designed for bone support.

Silicon dioxide is used to control moisture content and to help powders flow into capsules. Although silicon is sometimes confused with silicone (the synthetic substance used in breast implants), there is no chemical similarity between these two substances.

At Thorne, we take product quality extremely seriously.

We manufacture the great majority of our products to ensure complete supply chain transparency. This includes clean labels with full label disclosure and transparency. In addition, we have invested significantly in comprehensive testing, in sourcing the highest quality ingredients, and in creating “clean” manufacturing processes.

Although some supplement labels don’t declare the inactive ingredients used during manufacturing, Thorne does not hide anything. There are no hidden inactive ingredients – like preservatives, solvents, fillers, binders, or excipients.

What’s on a Thorne label is what’s in a Thorne product. All of the ingredients we put in the product are on the label. That is why Thorne is the brand trusted by health-care practitioners, U.S. National Teams, numerous professional sports teams, the UFC, and families around the world for 35 years.