Drug-checking (or pill-testing) services aim to reduce drug-related harm by better informing individuals about the contents of the drugs they intend to use. The specific potential harms addressed by drug-checking services vary according to local, national or regional drug scenes.

The service can also help to link people who use drugs with wider harm reduction services and inform public health agencies about the potency and quality of drugs in circulation. Many services include compulsory harm reduction counselling sessions, where people can be given advice on safer use strategies.