Biotherapeutic medicines, which are produced from biological sources such as living organisms rather than synthesised chemicals, are important treatments for many chronic diseases, such as cancers, diabetes, and rheumatoid arthritis, and other non-communicable diseases. Although a lot of research and development efforts are focused on innovative biotherapeutic products, the high cost and restricted market availability has limited their use. Biosimilars are a part of biotherapeutics that are structurally and functionally similar to an already-authorized reference biotherapeutics. Like generic medicines, biosimilars can be much less expensive versions of innovator biotherapeutics. As the patents of some biotherapeutics have expired, more biosimilars are being produced. Like generic medicines, biosimilars could help to increase access to treatment in lower-resourced countries and provide a solution to escalating health costs in high-income countries.