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 contami…