We are Bespoke Biotics founded by research scientists, making food nutritional products with love, tailoring our formulations to suit your health goals. Great supplements, developed in London & produced in the UK, in hygienic GMP facilities. OPTINAC N-Acetyl-Cysteine 600mg 120 capsules.N-Acetyl Cysteine (NAC) is a non-toxic stable form of L-Cysteine. OPTINAC also has a high bioavailability, and can therefore be used by the body more efficiently. NAC is an amino acid. Amino acids are the building blocks of protein.Suitable for vegetarians and vegans. Allergy Advice: According to our suppliers of raw material this product is free from all common allergens, including gluten, wheat, dairy, eggs, fish, crustaceans, molluscs, soy, sesame, celery and mustard.