The safety of red yeast rice products has not been established. Some commercial supplements have been found to contain high levels of the toxin citrinin. As commercial products will have highly variable amounts of monacolins, and rarely declare this content on the label, defining risk is difficult. Ingredient suppliers have also been suspected of "spiking" red yeast rice preparations with purified lovastatin. As evidence, one published analysis reported several commercial products as being almost entirely monacolin K – which would occur if the drug lovastatin was illegally added – rather than the expected composition of many monacolin compounds.