Free Radical Protection*/Normal Immune System Function*: N-Acetyl Cysteine (Nac) Is A Stable Form Of The Non-Essential Amino Acid Cysteine Maintains Cellular Health*: Nac Can Help To Support Healthy Brain And Neuronal Tissues Important Note About This Product: Black Spots May Appear In Nac Because Of A Normal Oxidative Reaction, But Product Is Safe To Consume. These Spots Are Not Mold Or Any Other Micro-Contamination. Micro-Testing Has Been Performed To Assess Product Safety Gmp Quality Assured: Npa A-Rated Gmp Certification Means That Every Aspect Of The Now Manufacturing Process Has Been Examined, Including Our Laboratory/Testing Methods (For Stability, Potency, And Product Formulation) Packaged In The Usa By A Family Owned And Operated Company Since 1968