Herbal products contain unlisted fillers

Users of natural health products should be careful. According to a new study from the University of Guelph, the majority of herbal products sold contain ingredients not listed on the label. Most companies use substitutes and cheaper alternatives and fillers.


The study was published in BMC Medicine and used barcoding technology to test 44 herbal products sold by 12 companies.
Only two of the companies tested provided authentic products without substitutes, contaminants or fillers. Overall, almost 60% of the products contained plant species that were not listed on the label. Researchers detected product substitutes in 32% of samples. More than 20% of the products contained fillers such as rice, soybeans and wheat that were not mentioned on the label.

Health risks

Contamination and substitutes in herbal products can pose significant health risks to consumers. Contamination with plants known to be poisonous was found in several products. These have side effects that interact negatively with other herbs, supplements and medications. Senna Alexandrina (Senna pod), a plant with a laxative effect, was found in one product . This is not intended for long-term use as it can cause chronic diarrhea and liver damage and negatively affect immune cells in the colon.
Several herbal products contain Parthenium Hysterophorus , which can cause swelling and numbness in the mouth, as well as tongue blisters and nausea. In addition, this herb reacts with medications for liver metabolism. One ginkgo product was contaminated with Juglans Nigra (black walnut), which could endanger people with nut allergies.


Off-label fillers such as wheat, soybeans and rice are also a concern for allergy sufferers seeking gluten-free products. It is common in natural products to use these types of fillers, which are mixed with the active ingredients. But a consumer has the right to see all plant species used in the production of a natural product listed.
Until now it has been very difficult to verify what was in capsules or tablets, but the research team has developed standard methods and tests that use DNA barcodes to detect the authentic ingredients in the herbal products.


It is necessary to protect consumers from the economic and health risks of herbal product fraud. There are now no standards to monitor herbal products.
Medicinal herbs are now the fastest growing segment of the North American alternative medicine market, with more than 29,000 herbal substances sold. More than 1,000 companies worldwide produce medicinal plant products worth more than 60 billion annually. About 80% of people in developed countries use natural health products, including vitamins, minerals and herbal remedies. Canada has regulated natural health products since 2004. Regulators are faced with a backlog of permit applications, and thousands of products on the market lack a full product permit. Globally, regulatory issues surrounding natural health products impact consistency and safety. The industry suffers from unethical activities by a number of manufacturers.