Re-evaluating the ordre public bar to cannabis patents in South Africa after decriminalisation

Background South African law treats different activities involving cannabis in distinct ways. Prince protects an adult's private use, possession, and cultivation for personal consumption, but the law still prohibits dealing and other activities. Parliament enacted the Cannabis for Private Purposes Act 7 of 2024, which currently awaits a presidential proclamation to take effect. This review assesses whether this legal framework causes every cannabis-related invention to fall under s 25(4)(a) of the Patents Act 57 of 1978. Main body This review doctrinally analyses s 25(4)(a) of South Africa's Patents Act. It compares that provision with the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS), the European Patent Convention (EPC), and materials from the African Regional Intellectual Property Organization (ARIPO). It also uses selected public patent records to test what available databases disclose. The analysis separates the moral controversy over cannabis, the legality of particular conduct, and the statutory effect of publishing or exploiting the claimed invention. The Prince decision addresses only part of this legal context. However, its privacy holding makes blanket criminality an unviable basis for refusing all cannabis patents. Section 25(4)(a) directs the inquiry into whether publishing or exploiting a particular invention would generally be expected to encourage offensive or immoral behaviour. The review also considers agrarian participation, genetic resource disclosure, and South Africa's unfinished move from depository registration to substantive search and examination. Conclusion Partial decriminalisation does not automatically entitle a cannabis invention to patent protection. Conversely, moral debate or strict regulation surrounding cannabis does not justify an automatic refusal. Standard patentability requirements perform most of the screening work. However, s 25(4)(a) remains available if publishing or exploiting a specific invention would generally encourage offensive or immoral conduct. Patent administration requires simultaneous improvement through rigorous examination, clear public records, and dependable safeguards for biodiversity, origin disclosure, and benefit sharing.