Regulation and Formulation of OTC NAC Supplements

Quality Control and Standardization

• The American Society of Health-System Pharmacists notes that OTC NAC supplements may have variable concentrations of NAC and inconsistent quality control, highlighting the need for caution when using these products 1
• The lack of governmental regulation of herbal supplements and dietary formulations, including OTC NAC products, can lead to variable NAC concentrations between different manufacturers and potential contamination or adulteration 1

Active Ingredients and Concentrations

• OTC NAC supplements may contain silymarin, a component of milk thistle products, at concentrations of 70-80%, although these concentrations are not governmentally regulated and may vary considerably between preparations and manufacturers 1