Herbal medicine is as central to Traditional Chinese Medicine (TCM) as acupuncture, and in China it is often the larger part of practice. In Canada it sits inside a specific regulatory system that most people never think about. This article explains how Chinese herbal medicine is traditionally used, how herbal products are regulated in Canada, and what the main safety concerns are. It is an educational overview, not advice to use any product.
How herbs are used in TCM
In TCM, herbs are rarely given alone. A practitioner traditionally combines several ingredients into a formula, chosen according to the pattern of imbalance identified in the TCM diagnosis rather than a single named disease. Classic formulas have been recorded and refined over many centuries, and they are adjusted for the individual. Formulas may be prepared as decoctions (herbs boiled in water), powders, granules or pills. How TCM arrives at a diagnostic pattern is explained in How Traditional Chinese Medicine Diagnoses Illness.
Herbal formulas were a regular part of Sherman Lai's practice in Guelph from 1986 to 2017. He presented clinical observations on herbal formulas at conferences in Canada and the United States. These were case series from his own practice, not placebo-controlled trials, and they are listed as a historical bibliography on the Research & Practice page.
How Canada regulates herbal products
In Canada, herbal products sold to the public are regulated by Health Canada as natural health products. The Natural Health Products Regulations came into force on January 1, 2004, and their definition of natural health products explicitly includes traditional medicines such as TCM.
Under the Regulations, a product needs a product licence before it can be sold, and the sites that manufacture, package, label or import it need site licences. A licensed product carries an eight-digit Natural Product Number (NPN) on its label, which consumers can look up in Health Canada's Licensed Natural Health Products Database. For products based on traditional medicine, Health Canada has a separate pathway that assesses a product on its documented traditional use within a recognized system such as TCM.
Health Canada's rules do not cover everything. Products compounded by a health care practitioner for an individual patient do not need a product licence. Products bought abroad or online from outside Canada may not have gone through Canadian licensing at all.
Safety concerns
The U.S. National Center for Complementary and Integrative Health (NCCIH) notes that "natural" does not mean safe. Some herbs used in Chinese medicine can cause serious side effects or interact with prescription drugs. Ephedra (ma huang) is a well-known example, linked to heart attack and stroke. NCCIH also reports that some Chinese herbal products sold in other countries have been found to contain undeclared drugs, such as the blood thinner warfarin, heavy metals such as lead and arsenic, pesticides, or the wrong herb.
On interactions, NCCIH notes that many reported herb-drug interactions come from laboratory or animal studies rather than clinical trials. Concern is highest with drugs that have a narrow safety margin, such as warfarin and digoxin. Health Canada advises people to tell their doctor and pharmacist about any natural health products they take and to look for an NPN on the label.
What the evidence can and cannot say
Research on Chinese herbal medicine is harder to summarize than research on acupuncture, because formulas vary so much from one practitioner and patient to the next. NCCIH notes that there is limited rigorous evidence on whether most Chinese herbal products work for the conditions they are used for. Health Canada's licensing of a traditional medicine reflects its documented traditional use, not proof from modern clinical trials. For context on how the research on TCM is evaluated, see What Does Research Say About Acupuncture?
Sources
- National Center for Complementary and Integrative Health (NIH). Traditional Chinese Medicine: What You Need To Know.
- National Center for Complementary and Integrative Health (NIH). Herb-Drug Interactions. Clinical digest for health professionals.
- Health Canada. Information Kit: Regulation of Natural Health Products.
- Health Canada. Pathway for Licensing Natural Health Products Used as Traditional Medicines.
- Health Canada. Safe Use of Natural Health Products.