OBJECTIVE: To examine existing evidence and inform family physicians about issues concerning herbal product use in Canada. QUALITY OF EVIDENCE: The Canadian Food and Drug Act and findings of an Expert Advisory Committee on Herbs and Botanical Preparations were consulted to provide an overview of the issues regarding herbal product regulation in Canada. Case reports of herbal toxicity were identified to illustrate some of the hazards of herbal products, and references provided to guide health professional in searching the literature for clinical trials that evaluate these drugs' efficacy. MAIN FINDINGS: Herbal products not registered as drugs in Canada are sold as foods and are exempt from the drug review process that evaluates product efficacy and safety. This places the public at risk of unwanted effects from the use of herbal products that are adulterated with other substances and of forgoing effective conventional therapy. Moreover, consumers are exposed to a plethora of information portraying herbal products as harmless. Some progress has been made to address these concerns by facilitating the registration of herbal products as drugs. CONCLUSIONS: Most herbal products that were evaluated were unsafe or ineffective, or no information was available to evaluate their efficacy. Despite the perception that herbal products are innocuous, family physicians need to be aware that herbal therapy can be harmful in order to help their patients make informed choices.