Restrictions on monetary payments for human biological substances in Japan: The mu-shou principle and its ethical implications for stem cell research

Restrictions on financial gains from the sale of human body parts is a leading policy issue surrounding the use of human tissues and cells. However, discrepancies exist between regulations and reality. In stem cell research, in which diverse sources of tissues and cells can be used, unclear regulations can impede research. Thus, using the Japanese system as a case study, we examined the challenges in the implementation of the “no payment” or the mu-shou principle in stem-cell research over the years. We reviewed 28 Japanese laws and governmental guidelines and summarized the scope of restrictions on payments for the donation and supply of human biological samples (HBS). As part of restrictions on financial rewards, the mu-shou principle emerged in Japanese laws and administrative documents in the 1990s. Although the Japanese mu-shou generally means “free” or “gratis” in English, its interpretation in research and development settings remains ambiguous. Traditionally, this principle was used to deny remuneration to donors. However, it is also inconsistently applied while processing and transferring human tissue after donation, which creates confusion among the various stakeholders. Recent policies have interpreted the principle in multiple ways: (1) treating the use of HBS for cell-processing as a non-profit activity; (2) a flexible interpretation of the principle to broaden the scope of user payments; and (3) removal of the principle itself to allow for commercial use. The inconsistencies in the monetary payment requirements for HBS could hinder research and development. After scrutinizing the principle's background, an effective approach is needed that considers the concerns of the providers, users, and society alike. •Japan’s mu-shou principle regulates payments to donors for human biological samples.•The scope of the mu-shou principle varies and is often not explicitly stated.•Inconsistent monetary payment requirements for samples are a destabilizing factor.•An effective approach must consider the needs of the providers and society alike.