Botanical Dietary Supplements

Background Information

Botanical dietary supplements, sometimes called herbals or herbal dietary supplements, are products made from plants, plant parts, or plant extracts. They are meant to be consumed and contain one or more ingredients meant to supplement the diet. One recent nationwide government survey found that natural products, including dietary supplements, are used by approximately 18% of adults.

Botanical dietary supplements are used in both traditional and complementary medicine, and take many forms, including:

  • Tablets
  • Capsules
  • Softgels
  • Gelcaps
  • Liquids
  • Powders

Echinacea, green tea extract, garlic, and evening primrose oil are common examples of botanical dietary supplements used for health.

If a manufacturer wants to distribute a supplement containing a new dietary ingredient, they first must notify the U.S. Food and Drug Administration (FDA) before it can be sold. But notifying the FDA doesn't mean the FDA deems the ingredients or supplement as safe. The FDA is only responsible for taking action against products found to be harmful after they have started selling in the market.

NTP has received multiple nominations from the public and other federal agencies to study various botanical dietary supplements. This research is not concerned with the benefits of the supplement. Instead, NTP studies are designed to identify any potential harm from short and long-term exposure to these substances.

NTP Studies & Findings

NTP is conducting multiple studies to identify the potential harm of short and long-term exposure to botanical dietary supplements. These studies may provide toxicology data and help in determining the safety or risk of certain supplements. This data can be used by:

  • U.S. Food and Drug Administration
  • National Institutes of Health
  • Public
  • Health care providers
  • Foreign Governments
  • Other stakeholders

Below are NTP's ongoing and completed studies, each with a link to the testing status page, any recent updates, and any available reports.

Ongoing NTP Studies
Botanical Dietary Supplement Commonly Used For Testing Status
Black Cohosh Menstrual and menopausal symptoms Ongoing
Echinacea Purpurea Common cold and other infections Ongoing
Garcinia Cambogia Appetite suppression and weight loss Ongoing
Valerian Root Insomnia and other sleep disorders Ongoing
Completed NTP Studies
Botanical Dietary Supplement Commonly Used For Testing Status
Aloe Vera Constipation and gastrointestinal disorders Completed
Bitter Orange Heartburn, congestion, weight loss Completed
Black Cohosh Menstrual and menopausal symptoms
Ephedra Weight loss, energy, performance Completed
Ginkgo Biloba Brain function and memory Completed
Ginseng General well-being, improved physical stamina, and concentration Completed
Goldenseal Skin disorders, ulcers, and fevers Completed
Green Tea Extract Mental alertness, digestive symptoms, headaches, and weight loss Completed
Gum Guggul Lowering cholesterol, acne, and weight loss Completed
Kava Kava Anxiety Completed
Milk Thistle Liver cirrhosis, chronic hepatitis, and gall bladder disorders, in addition to other ailments Completed
Senna Constipation, irritable bowel syndrome, hemorrhoids, and weight loss Completed
Usnea Lichen Weight loss Completed
Vinpocetine Memory enhancement Completed

Informational Resources

Fact Sheets and FAQs
Other Resources
  • Catlin, N.R., Collins, B.J., Auerbach, S.S., Ferguson, S.S., Harnly, J.M., Gennings, C., Waidyanatha, S., Rice, G.E., Smith-Roe, S.L., Witt, K.L., Rider C.V. How similar is similar enough? A sufficient similarity case study with Ginkgo biloba extract. (2018). Food Chem. Toxicol. 118:328-339;
  • Collins BJ, Kerns SP, Aillon K Mueller G, Rider CV, DeRose EF, London RE, Harnly JM, Waidyanatha S. Comparison of phytochemical composition of Ginkgo biloba extracts using a combination of non-targeted and targeted analytical approaches. Anal Bioanal Chem 412, 6789–6809 (2020);
  • Hubbard, T.D., Hsieh, J.H., Rider, C.V., Sipes, N.S., Sedykh, A., Collins, B.J., Auerbach, S.S., Xia, M., Huang, R., Walker, N.J., DeVito, M.J. (2019). Using Tox21 High-Throughput Screening Assays for the Evaluation of Botanical and Dietary Supplements. Appl. In Vitro Toxicol. 5(1):10-25;
  • Rider, C.V., Walker, N.J., Waidyanatha, S. Getting to the Root of the Matter: Challenges and Recommendations for Assessing the Safety of Botanical Dietary Supplements. (2018). Clin. Pharmacol. Ther. 104(3): 429-431;
  • Roberts, G.K., Gardner, D., Foster, P.M., Howard, P.C., Lui, E., Walker, L., van Breemen, R.B., Auerbach, S.S., Rider, C. Finding the bad actor: Challenges in identifying toxic constituents in botanical dietary supplements. (2019). Food Chem. Toxicol. 124: 431-438;
  • Ryan, K.R., Huang, M.C., Ferguson, S.S., Waidyanatha, S., Ramaiahgari, S., Rice, J.R., Dunlap, P.E., Auerbach, S.S., Mutlu, E., Cristy, T., Peirfelice, J., DeVito, M.J., Smith-Roe, S.L., Rider, C.V. (2019). Evaluating Sufficient Similarity of Botanical Dietary Supplements: Combining Chemical and In Vitro Biological Data. Toxicol. Sci. 172(2): 316-329;
  • Shipkowski, K.A., Betz, J.M., Birnbaum, L.S., Bucher, J.R., Coates, P.M., Hopp, D.C., MacKay, D., Oketch-Rabah H., Walker, N.J., Welch, C., Rider, C.V. (2018). Naturally complex: Perspectives and challenges associated with Botanical Dietary Supplement Safety assessment. Food Chem. Toxicol. 118: 963-971;
  • Waidyanatha, S., Mutlu, E., Gibbs S., Stiffler, B., Andre, J., Burback, B., Rider, C.V. (2019). Systemic exposure to Ginkgo biloba extract in male F344/NCrl rats: Relevance to humans. Food Chem. Toxicol. 131;
  • Waidyanatha, S., Pierfelice, J., Cristy, T., Mutlu, E., Burback, B., Rider, C.V., Ryan, K. (2020). A strategy for test article selection and phytochemical characterization of Echinacea purpurea extract for safety testing. Food Chem. Toxicol. 137;
  • Waidyanatha, S., Ryan, K., Roe, A.L., Jia, W., Paine, M.F., Ferguson, S., Gurley, B.J., Welch, K., Chow, M.S.S., Devito, M., Rider, C. Follow that botanical: Challenges and recommendations for assessing absorption, distribution, metabolism and excretion of botanical dietary supplements. (2019). 121: 194-202;

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