If you ever look at the list of ingredients on your supplement bottles, you’ll notice there’s a section called “other ingredients”, also known as excipients.

What does excipient mean? In this article, we’ll define excipient, note important considerations about excipients, and list the most common ingredients to look for.

Man holding a supplement bottle and looking at more supplements

An excipient is any component other than the active ingredients that’s present in a supplement or pharmaceutical medication.

What is an excipient?

An excipient is any component other than the active ingredients that’s present in a supplement or pharmaceutical medication. Excipients in supplements are comparable to food additives, which are ingredients added to manufactured or packaged food for the purpose of improving taste, texture, appearance, nutritional value, and preservation. (8)

Although excipients don’t have active effects, the formulation of many supplements requires the combination of active ingredients with some additional non-dietary ingredients during the manufacturing process and in the finished product. It’s even possible that an excipient used during manufacturing is not present in the final product. (2)(3)

Why are excipients in my products?

Excipients are often used to facilitate the manufacturing process, assist in product identification, and act as the carrier or component of the carrier of the active substance. (2)

Excipients may be used to enhance the finished product’s appearance, stability, patient acceptance (satisfaction), and bioavailability (proportion of the active ingredient that is absorbed and available for use). Protecting, supporting, and enhancing stability improves overall safety and function of the product during transport, storage, and use. (2) Many excipient ingredients are used for more than one function or purpose. (9)

Excipients in supplements are used for various functions, which include:

  • Acidifying/alkalizing agent
  • Aerosol propellant
  • Antifoaming agent
  • Antioxidant
  • Binding agent
  • Buffering agent
  • Carrier/vehicle
  • Chelating/sequestering agent
  • Coating agent
  • Coloring, flavor, perfume
  • Diluting/bulking agent (to improve dose accuracy)
  • Disintegrant (to aid dissolution in the gastrointestinal tract)
  • Emulsifier
  • Glidant/anticaking agent
  • Granulating agent
  • Humectant (to preserve moisture)
  • Lubricant
  • Ointment/suppository base
  • Plasticizer
  • Preservation agent
  • Stiffening agent
  • Suspending agent
  • Sweetener (2)(3)
Hand holding a supplement bottle with more bottles in the background

Excipients commonly have more than one function or desired effect that they are used for.

Health effects of common excipients

Certain excipient ingredients have been found to increase the effectiveness of dietary supplements. For example, a study investigated the bioavailability of a formulation called CoQ10 phytosome that combines the active ingredient, coenzyme Q10 (CoQ10), with an excipient, sunflower lecithin, used to increase the solubility of the product. The study found that CoQ10 absorption with CoQ10 phytosome was three times higher compared to CoQ10 alone. (5)

Excipients are also used to ensure the survival and stability of active ingredients during the digestive process. One experimental study examined the effects of various additives on the survival of an encapsulated Lactobacillus casei probiotic strain in conditions that simulate digestive bile salts and the environment in the colon. The findings demonstrate that adding maize starch (corn starch) and a stearic acid coating protected the probiotic in these conditions. When these two excipients were used, the probiotic cells were also fully released in a solution mimicking the pH (acid-base balance) in the colon, suggesting that products manufactured in this way will release probiotics in the target area of the body. (4)

Certain ingredients that are used as excipients are sometimes also used as active ingredients. For instance, ascorbic acid and ɑ-tocopherol are used as excipients for their antioxidant properties, and are also used as active ingredients in vitamin C and E supplements, respectively. (2)

Excipients in supplements

Excipients that are used in supplements and pharmaceuticals can be derived from plant and animal sources or be chemically manufactured. (6) Commonly used excipients in supplements include:

  • Ascorbic acid
  • Aspartic acid
  • Aspartame
  • Carrageenan
  • Castor oil
  • Cellulose
  • Glycerides, polyglycerides (of hydrogenated vegetable oils)
  • Glyceryl behenate
  • Lactose
  • Lecithin
  • Magnesium stearate
  • Mineral oil
  • Polyethylene glycol
  • Polyacrylamide
  • Polydextrose
  • Polysorbate 80
  • Polyvinylpyrrolidone
  • Propyl gallate
  • Silicon dioxide
  • Soybean oil fatty acids
  • Stearic acid
  • Terpene resin (9)

For more information on reading dietary supplement labels, visit the Fullscript blog.

What kind of regulations are there about excipients in products?

In the United States, food additives are regulated by the Food and Drug Administration (FDA). Non-dietary ingredients, including excipients, that are present in dietary supplements must comply with regulations for food additives or be “Generally Recognized as Safe” (GRAS) for their intended use. (7)

Any non-dietary ingredient has to meet the following criteria:

  • A premarket approval based on data demonstrating safety
  • Both evidence of safety and a basis to conclude that this evidence is generally known and accepted by qualified experts
  • Regulations specifying the conditions under which the additive has been demonstrated to be safe and, therefore, may be lawfully used
  • Scientific evidence generally available to establish the safety of the substance for its intended use (7)

Safety of excipients in supplements

A common concern with additives or excipients is their potential negative health effects. When used as directed, excipients are generally safe to use and pose few health risks. Some of the most common adverse effects of excipients include allergic reactions, gastrointestinal upset, and skin hypersensitivity reactions. (1)(6)(10) Individuals with sensitivities or allergies to certain ingredients, such as artificial sweeteners or lactose, should carefully read supplement labels to ensure the product doesn’t contain the offending ingredient.

The bottom line

Excipients are inactive ingredients commonly used as additives in supplements for numerous purposes, such as enhancing appearance, improving bioavailability, and enhancing the stability of active ingredients. Excipients in supplements must meet regulations for food additives, ensuring their safety for human consumption.

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  1. Balbani, A. P. S., Stelzer, L. B., & Montovani, J. C. (2006). Pharmaceutical excipients and the information on drug labels. Brazilian Journal of Otorhinolaryngology, 72(3), 400–406.
  2. Furrer, P. (2018, January 5). The central role of excipients in drug formulation. Retrieved from https://www.europeanpharmaceuticalreview.com/article/18434/the-central-role-of-excipients-in-drug-formulation-2/
  3. Haywood, A., & Glass, B. D. (2011). Pharmaceutical excipients – where do we begin? Australian Prescriber, 34(4), 112–114.
  4. Mandal, S., Hati, S., Puniya, A. K., Khamrui, K., & Singh, K. (2014). Enhancement of survival of alginate-encapsulated Lactobacillus casei NCDC 298. Journal of the Science of Food and Agriculture, 94(10), 1994–2001.
  5. Petrangolini, G., Ronchi, M., Frattini, E., De Combarieu, E., Allegrini, P., & Riva, A. (2019). A new food-grade coenzyme q10 formulation improves bioavailability: Single and repeated pharmacokinetic studies in healthy volunteers. Current Drug Delivery, 16(8), 759–767.
  6. Reker, D., Blum, S. M., Steiger, C., Anger, K. E., Sommer, J. M., Fanikos, J., & Traverso, G. (2019). “Inactive” ingredients in oral medications. Science Translational Medicine, 11(483), eaau6753.
  7. U.S. Food and Drug Administration. (2014, January). Guidance for industry considerations regarding substances added to foods, including beverages and dietary supplements. Retrieved from https://www.fda.gov/media/87680/download
  8. U.S. Food and Drug Administration. (2018, February 6). Overview of food ingredients, additives & colors. https://www.fda.gov/food/food-ingredients-packaging/overview-food-ingredients-additives-colors
  9. U.S. Food and Drug Administration. (2019, October 24). Food additive status list. Retrieved from https://www.fda.gov/food/food-additives-petitions/food-additive-status-list
  10. Woods, D. (2001). Adverse effects of excipients. Retrieved from http://www.fshealth.gov.za/subsites/DWoods/Frontpages/excipients.HTML