It has been known for several decades that L-cysteine (a nonessential amino acid) is able to eliminate the toxicity of acetaldehyde by reacting covalently with acetaldehyde to form a stable 2-methylthiazolidine-4-carboxylic acid (MTCA). This simple principle was used in the recent innovation of Biohit HealthCare's Acetium™ capsule containing 100mg L-cysteine. Oral administration of Acetium was confirmed to effectively bind acetaldehyde originated from ethanol metabolism in the stomach, raising the idea that L-cysteine could also be used to eliminate acetaldehyde dissolved into the saliva during smoking. Indeed, Salaspuro et al. (2006) confirmed that orally administered L-cysteine (5mg)-containing sucking tablet (lozenge) totally inactivated acetaldehyde in the saliva during smoking.