Drug checking or pill testing is a way to reduce the harm from drug consumption by allowing users to find out the content and purity of substances that they intend to consume. This enables users to make safer choices: to avoid more dangerous substances, to use smaller quantities, and to avoid dangerous combinations.

A counterfeit medication or a counterfeit drug is a medication or pharmaceutical item which is produced and sold with the intent to deceptively represent its origin, authenticity, or effectiveness. A counterfeit drug may contain inappropriate quantities of active ingredients, or none, may be improperly processed within the body, may contain ingredients that are not on the label, or may be supplied with inaccurate or fake packaging and labeling. Counterfeit drugs are related to pharma fraud. Drug manufacturers and distributors are increasingly investing in countermeasures, such as traceability and authentication technologies, to try to minimise the impact of counterfeit drugs. Antibiotics with insufficient quantities of an active ingredient add to the problem of antibiotic resistance.