N-Acetyl Cysteine (NAC) has been investigated as a potential aid for treating addictions, including tobacco smoking and chewing, based on scientific rationale rather than traditional use. The primary mechanism relates to NAC’s role in modulating the brain’s glutamatergic system. Chronic use of addictive substances, such as nicotine, disrupts glutamate homeostasis, particularly in areas like the nucleus accumbens, which is central to reward and addiction pathways. NAC is a precursor to the antioxidant glutathione and appears to restore glutamate balance by stimulating the cystine-glutamate antiporter, potentially reducing cravings and the risk of relapse.

Multiple randomized controlled trials and systematic reviews have assessed NAC’s efficacy in substance use disorders. For tobacco use, a few small clinical studies (e.g., Knackstedt et al., 2009; Schmaal et al., 2011) found that NAC may reduce craving and, to a lesser extent, cigarette consumption. However, results have been mixed, with some trials reporting no significant benefit over placebo. Meta-analyses and reviews (e.g., Dean et al., 2011; Duailibi et al., 2017) generally conclude that while NAC is promising and well-tolerated, the evidence base is still limited, and larger, more rigorous studies are needed.

In summary, the use of NAC for tobacco addiction is supported by plausible neurobiological mechanisms and preliminary clinical evidence, but it is not yet established as a first-line or standard treatment.