NAC is valued primarily for its role in antioxidant production.
Along with two other amino acids — glutamine and glycine — NAC is needed to make and replenish glutathione.
Glutathione is one of the body’s most important antioxidants, which helps neutralize free radicals that can damage cells and tissues in your body.
It’s essential for immune health and fighting cellular damage. Some researchers believe it may even contribute to longevity (1Trusted Source).
Its antioxidant properties are also important for combatting numerous other ailments caused by oxidative stress, such as heart disease, infertility and some psychiatric conditions (2Trusted Source).
NAC plays an important role in your body’s detoxification process.
It can help prevent side effects of drugs and environmental toxins (3Trusted Source).
In fact, doctors regularly give intravenous (IV) NAC to people with an acetaminophen overdose to prevent or reduce kidney and liver damage (4Trusted Source).
NAC also has applications for other liver diseases due to its antioxidant and anti-inflammatory benefits (5Trusted Source).
NAC helps regulate levels of glutamate — the most important neurotransmitter in your brain
While glutamate is required for normal brain action, excess glutamate paired with glutathione depletion can cause brain damage.
This may contribute to mental health conditions, such as bipolar disorder, schizophrenia, obsessive-compulsive disorder (OCD) and addictive behavior
For people with bipolar disease and depression, NAC may help decrease symptoms and improve your overall ability to function. What’s more, research suggests that it may play a role in treating moderate to severe OCD
Likewise, an animal study implied that NAC may minimize negative effects of schizophrenia, such as social withdrawal, apathy and reduced attention spans
NAC supplements can also help decrease withdrawal symptoms and prevent relapse in cocaine addicts
Additionally, preliminary studies show that NAC may decrease marijuana and nicotine use and cravings
Many of these disorders have limited or currently ineffective treatment options. NAC may be an effective aid for individuals with these conditions
NAC can relieve symptoms of respiratory conditions by acting as an antioxidant and expectorant, loosening mucus in your air passageways.
As an antioxidant, NAC helps replenish glutathione levels in your lungs and reduces inflammation in your bronchial tubes and lung tissue.
People with chronic obstructive pulmonary disease (COPD) experience long-term oxidative damage and inflammation of lung tissue, which causes airways to constrict — leading to shortness of breath and coughing.
NAC supplements have been used to improve COPD symptoms, exacerbations and lung decline
In a one-year study, 600 mg of NAC twice a day significantly improved lung function and symptoms in those with stable COPD
Those with chronic bronchitis can also benefit from NAC.
Bronchitis occurs when the mucous membranes in your lungs’ bronchial passageways become inflamed, swell and shut off airways to your lungs
By thinning mucus in your bronchial tubes and boosting glutathione levels, NAC may help decrease the severity and frequency of wheezing, coughing and respiratory attacks
In addition to relieving COPD and bronchitis, NAC may improve other lung and respiratory tract conditions like cystic fibrosis, asthma and pulmonary fibrosis, as well as symptoms of nasal and sinus congestion due to allergies or infections
NAC’s ability to replenish glutathione and regulate brain glutamate levels can boost brain health.
The brain neurotransmitter glutamate is involved in a broad range of learning, behavior and memory actions, while the antioxidant glutathione helps reduce oxidative damage to brain cells associated with aging
Because NAC helps regulate glutamate levels and replenish glutathione, it may benefit those with brain and memory ailments
The neurological disorder Alzheimer’s disease slows down a person’s learning and memory capacity. Animal studies suggest that NAC may slow the loss of cognitive ability in people with Alzheimer’s
Another brain condition, Parkinson’s disease, is characterized by the deterioration of cells that generate the neurotransmitter dopamine. Both oxidative damage to cells and a decrease in antioxidant ability contribute to this disease.
NAC supplements appear to improve both dopamine function and disease symptoms such as tremors
Approximately 15% of all couples trying to conceive are affected by infertility. In almost half of these cases, male infertility is the main contributing factor
Many male infertility issues increase when antioxidant levels are insufficient to combat free radical formation in your reproductive system. The oxidative stress can cause cell death and reduced fertility
In some cases, NAC has been shown to improve male fertility.
One condition that contributes to male infertility is varicocele — when veins inside the scrotum become enlarged due to free radical damage. Surgery is the primary treatment.
In one study, 35 men with varicocele were given 600 mg of NAC per day for three months post-surgery. The combination of surgery and NAC supplement improved semen integrity and partner pregnancy rate by 22% compared to the control group
Another study in 468 men with infertility found that supplementing with 600 mg of NAC and 200 mcg of selenium for 26 weeks improved semen quality
Researchers suggested that this combined supplement should be considered as a treatment option for male infertility.