This lecture delves into the stringent compliance requirements of drug testing programs within legal, ethical, and scientific frameworks. It underscores the necessity of both substantive and procedural fairness in these programs, emphasising due legal processes such as notice, impartial hearings, and the opportunity for defence alongside rigorous analytical testing procedures. Ethical guidelines further bolster these legal principles, demanding consent, confidentiality, and the avoidance of medical malpractice. The lecture also highlights the importance of scientific rigour in testing, where accuracy and the veracity of results are paramount, and any deviation or ignorance in testing protocols can lead to serious legal and ethical consequences, including potential charges of medical malpractice or delict. Additionally, the concept of “zero-tolerance” in South Africa is critically examined, advocating for a shift towards a more precise “no tolerance” policy to better align with legal and ethical standards.