The Specific Substances category focuses on health issues related to substances humans deliberately put into their bodies. Sites appropriate for this category include consumer information, professional information, organizations, services, and personal experiences. Sites not listed in this category:

• Topics related to public policy issues are organized in Society: Issues: Health.
• Topics related to environmental exposure to toxic substances are organized in Science: Environment: Environmental Health: Toxic Substances.
• Topics related to occupational exposure to hazardous substances are organized in Health: Occupational Health and Safety: Hazardous Substances.
• Topics related to drugs and medications synthesized and manufactured for treating specific conditions and diseases are organized in Health: Pharmacy: Drugs and Medications.
• Topics related to herbal medications are organized in Health: Alternative: Herbs.
• Online retailers of products are organized in Shopping.