Drug safety is not a matter for healthcare professionals alone. Patients are also involved, at three different levels: (i) in the behaviours patients adopt to reduce the adverse effects of the drugs; (ii) in regard to what some doctors say to their patients about drug risks; and (iii) in what the pharmaceutical industry says about self-medication and risks. This article will examine these aspects on the basis of information gathered in France during anthropological studies on drug use. (i) Patients' concerns about reducing adverse effects give rise to a series of behaviours relating to drug use. Patients start with the identification of what they regard as a risk inherent in the substances or linked to the uncontrolled use of drugs, and try to neutralize the risk by modifying or modulating the prescriptions in line with various parameters. Dimensions as varied as the nature of the prescribed drugs, the quantity, the dosage and the preservation of certain functions or organs are taken into account, and patients follow their own rules of conduct in order to reduce risks. These dimensions bring into play characteristics of both the drug and the individual, and take into account the effects or the risks of drugs in their physical, psychic, behavioural and social aspects. (ii) Doctors' discourse towards patients regarding the risks and possible effects of drugs is examined, in particular the discourse of those who choose to hide the undesirable effects of drugs from their patients with the aim of not jeopardizing the patient's compliance. This situation involves comparing two logics: ethics of care versus ethics of information. (iii) Regarding the pharmaceutical industry's discourse on self-medication and risks, although on the one hand it promotes self-medication on the basis of patients' growing desire for autonomy and competency, on the other hand it discourages the use of the home medicine cabinet for reasons of safety, which questions the ability of patients to use drugs properly. This article aims to demonstrate that the various behaviours and discourses relating to the risks of drugs are embedded with symbolic, ethical and cultural logics. As a consequence, above and beyond work carried out on the question of pharmacovigilance, examining the issue of safe drug use involves studying the human - social and cultural - aspects that govern part of the behaviours and practices relating to drug safety.