Herbal product safety
Lessons from the red yeast rice contamination
The safety of herbal products hinges on quality at every stage, from plant identity and purity to processing and storage. When these controls fail, the consequences can be severe. A well-documented case of herbal quality failure is the 2024 red yeast rice contamination in Japan. A widely-used cholesterol-lowering supplement became a public health disaster when contaminated batches containing poorly controlled fermentation produced puberulic acid, a nephrotoxin that caused Fanconi syndrome, acute kidney injury, and over 70 deaths (Maruyama et al., 2025; Chikasue et al., 2024). Most patients did not fully recover, underscoring the irreversibility of harm that can occur when unsafe products reach the public.
What made this event especially alarming is that red yeast rice is a mainstream product. Its active compound, monacolin K, is chemically identical to lovastatin, providing RYR with the pharmaceutical effects without requiring pharmaceutical oversight. RYR also has a history of contamination with citrinin, a nephrotoxin mycotoxin. Even in controlled settings, the margin for error with this ingredient is razor-thin (Vanhee et al., 2024).
In response, regulatory frameworks have begun evolving to prevent such outcomes. Japan is mandating Good Manufacturing Practices (GMP) by 2026 for supplements labeled under its Foods with Function Claims (Sato et al., 2025). In Europe, caps on certain compounds were imposed following the discovery of RYR adulteration and contamination in 11% of products tested (Vanhee et al., 2024). These standards aim to enforce consistency, safety, and accurate labeling, deficiencies that remain widespread globally. While these responses were necessary, they were not entirely effective. Recalls and future GMP mandates were reactive, and the scale of injury in the RYR case suggests there were systemic blind spots long before these products reached consumers. Implementing GMP by 2026 in Japan is a step forward but it does not undo the harm already caused, and it raises questions about why those controls were not in place earlier for such widely used products.
Similarly, while the EU’s limitations on monacolin K and citrinin show progress, they still rely heavily on post-market enforcement. In reality, what is needed is a shift from catching problems downstream to preventing them upstream through enforceable standards, transparent sourcing, and proactive testing.
In low-resource settings, challenges are more acute. A 2025 assessment in Uganda revealed that most herbal manufacturers fail to adhere to basic Good Manufacturing Practice (GMP) standards, characterized by inadequate sanitation, the absence of quality documentation, and a lack of systems for managing consumer complaints (Shubham & Pandey, 2025). The authors suggest introducing tiered GMP models to help resource-limited producers gradually improve compliance without compromising safety. Even in high-income countries, we are mostly responding after the fact. Testing products after they have already harmed someone is not a viable safety strategy. Real quality means upstream controls, including verified plant identity, contamination thresholds, processing transparency, and the application of GM at every phase.
Ultimately, the safety of herbal products is essentially a matter of execution. Herbs can offer therapeutic value, but without robust quality systems, they can carry unnecessary risks. The RYR case was not a failure of traditional medicine; it was a failure of oversight. As the herbal market continues to grow, particularly in the context of chronic disease and preventive health, regulators, manufacturers, and practitioners share a responsibility to prioritize quality. Not just to meet requirements but because people's health depends on it.
References
Vanhee, C., Jacobs, B., Canfyn, M., Malysheva, S. V., Willocx, M., Masquelier, J., & Van Hoorde, K. (2024). Quality Control and Safety Assessment of Online-Purchased Food Supplements Containing Red Yeast Rice (RYR). Foods (Basel, Switzerland), 13(12), 1919. https://doi.org/10.3390/foods13121919
Chikasue, A., Taguchi, K., Iwatani, R., Kimura, K., Okuda, S., Uesugi, N., & Fukami, K. (2025). Three Cases of Red Yeast Rice-Containing Supplement-Induced Acute Kidney Injury and Fanconi Syndrome. American journal of kidney diseases : the official journal of the National Kidney Foundation, 85(4), 522–526. https://doi.org/10.1053/j.ajkd.2024.08.007
Maruyama, H., Sada, K. E., Oka, M., Yanai, M., Hidaka, S., & Kobayashi, S. (2025). Successful Resolution of Suspected Red Yeast Rice-induced Nephropathy. Internal medicine (Tokyo, Japan), 10.2169/internalmedicine.4908-24. Advance online publication. https://doi.org/10.2169/internalmedicine.4908-24
Sato, K., Kodama, K., & Sengoku, S. (2025). The Co-Evolution of Markets and Regulation in the Japanese Functional Food Industry: Balancing Risk and Benefit. Foods (Basel, Switzerland), 14(9), 1581. https://doi.org/10.3390/foods14091581