N-ACETYLCYSTEINE

What is N-acetylcysteine or NAC?

N-acetylcysteine, or NAC, is often used to treat acetaminophen overdose. It is a precursor of L-cystine, which boosts the formation of L-cysteine. NAC is a powerful antioxidant. It protects mitochondria, which are the energy powerhouses of cells. It can treat diseases by itself or in conjunction with other medications. Bronchitis, colitis, liver cancer, hemodialysis, asthma, concussions [^[1]], and neurodegenerative diseases are some therapeutic targets that are evidenced to be improved with NAC [^[2]].

What does NAC do in the body?

NAC is a potent antioxidant and anti-inflammatory compound [^[3]].It is considered a mucolytic, which means it breaks up mucus in the lungs to make breathing easier [^[4]]. As an antioxidant, NAC reduces levels of inflammatory substances [^[3]]. It can scavenge free radicals as an antioxidant, protecting the lungs from stressors such as infections and pollution [^[4]]. It also can improve brain damage produced from ischemic events, reduce pain in an infection, and reduce the inflammatory response in the thyroid [^[3]].

How can NAC help alleviate certain Long COVID symptoms and/or pathophysiology? 

Research shows that COVID-19 can benefit from NAC in the acute phase. NAC led to decreased C-reactive protein levels, a marker of inflammation, and a significant oxygen saturation increase, reducing COVID-19 mortality [^[5]].

Long COVID patients can also benefit from NAC. NAC lowers homocysteine levels, a marker of cardiovascular stress, reducing heart risks for long COVID patients, who are already at greater risk of clotting events than those not long-haulers [^[6]].

In one study combining guanfacine with NAC, patients saw a decrease in Long COVID “brain fog.” Eight out of twelve patients participating in the study experienced improvements in working memory, concentration, and executive function. Some patients were able to go back to their normal workloads [^[7]]. While more research is needed to elucidate other benefits of NAC and how its antioxidant and cellular health mechanisms work in different conditions, the cognitive benefits of NAC for long COVID are promising. The fact that NAC has good safety, absorption, and bioavailability, and is available cheaply, is another advantage for people suffering from Long COVID [^[3]].