Topic overview

Start with the big picture

Evaluating an herbal product requires attention to both its claimed benefits and the reliability of the evidence supporting them. Few products have extensive high-quality trial data, while species, growing conditions, harvest, and processing can affect composition and potency. Standardization and quality systems aim to improve consistency, but contamination or adulteration can still pose risks. Clinically important issues include interactions involving drug-metabolizing enzymes or transporters, well-documented toxicities, and under-reporting of adverse events. Regulatory pathways differ between the United States and the European Union, and product claims and labeling are subject to distinct requirements. This preview introduces these connected issues; the deeper lesson develops them across evidence, quality, clinical safety, regulation, and related topics.