On March 28th, Kobayashi Pharmaceutical reported to Japan’s Ministry of Health, Labour, and Welfare that an “unexpected” substance, Puberuic acid, was found in a problematic batch of red yeast rice supplements, possibly contaminated at the Osaka factory.
Puberuic acid, a natural compound produced by Penicillium molds, is poorly researched but shows promising anti-malarial properties alongside potential toxicity. A study in 2017 revealed mortality in mice following subcutaneous injections of 5 mg/kg of Puberuic acid, raising concerns about its presence in products and its potential link to kidney damage in consumers, currently under investigation.