N-AcetylCysteine (NAC) -1


Clinical use

Bronchial Disease

Chronic Bronchitis
Chronic Obstructive Pulmonary Disease (COPD)
Angina Pectoris
Mucolytic therapy
Colon Cancer Prevention
Nephroprotective agent
Paracetamol overdose
Insulin Resistance Syndrome
Hepatorenal Syndrome

Other Usages & Dosage forms

Other usages
Dosage forms

HSCH2CH(NHCOCH3)COOH Crystals with a melting point of 109-110°C; used as a mucolytic drug.

Acetylcysteine, also known as N-acetylcysteine (abbreviated NAC), is a pharmacological agent used mainly as a mucolytic and in the management of Paracetamol overdose.
NAC (N-Acetyl-Cysteine) is a precursor of glutathione in the body. This valuable glutathione precursor boosts cellular antioxidant protection.
This sulfur-containing compound, derived from the amino acid cysteine, can serve as a nutritional substrate for synthesis of intercellular glutathione, an important antioxidant.
Unlike cysteine, NAC is virtually non-toxic and is the preferred nutrient for enhancing glutathione levels inside cells. Take with multi-vitamins and minerals for maximum benefit.

  • Acetylcysteine
  • Acetylcysteine is the N-acetyl derivative of the amino acid L-cysteine, and is a precursor in the formation of the antioxidant glutathione in the body. The thiol (sulfhydryl) group confers antioxidant effects and is able to reduce free radicals.

Clinical use:
Evidence suggests that regular use of N-acetyl-cysteine (NAC) is helpful for individuals with chronic bronchitis, a condition commonly associated with smoking and emphysema. NAC is a natural expectorant which help thin mucus and loosen phlegm and bronchial secretions.

Mixed evidence suggests that NAC may be helpful for people who take the drug nitroglycerin for angina. NAC may also be helpful in a life-threatening condition called
Acute respiratory distress syndrome'(ARDS):also known as respiratory distress syndrome (RDS) or adult respiratory distress syndrome (in contrast with IRDS) is a serious reaction to various forms of injuries to the lung.'
Very preliminary evidence indicates that NAC may help prevent colon cancer and slow the progression of
Alzheimer's Disease'Alzheimers is a degenerative and terminal disease for which there is no known cure. In its most common form, it afflicts individuals over 65 years old, although a less prevalent early-onset form also exists '
. NAC is often used by people with HIV in hopes of enhancing immune function.

Chronic Bronchitis:
Individuals who have smoked cigarettes for many years eventually develop deterioration in their lungs leading to various symptoms, including chronic production of thick mucus. This so-called chronic bronchitis tends to flare up periodically into severe acute attacks possibly requiring hospitalization.
Regular use of NAC may diminish the number of these attacks. A review and meta-analysis selected eight double-blind placebo-controlled trials of NAC for chronic bronchitis. 1-9 The results of these studies, involving a total of about 1,400 individuals, suggest that NAC taken daily at a dose of 400 to 1,200 mg can reduce the number of acute attacks of severe bronchitis.

Chronic Obstructive Pulmonary Disease (COPD):
A chronic lung disease, such as asthma or emphysema, in which breathing becomes slowed or forced.

The main risk factor in the development of COPD is smoking. Approximately 15% of all chronic smokers will develop the disease. In susceptible people, this causes chronic inflammation of the bronchi and eventual airway obstruction.

Other etiologies include:
  • Alpha 1-antitrypsin deficiency'is a genetic disorder caused by defective production of alpha 1-antitrypsin (A1AT),leading to decreased A1AT activity in the blood and lungs, and deposition of excessive abnormal A1AT protein in liver cells'
    (augmented by smoking)
  • Byssinosis'Byssinosis:also called (brown lung), is an occupational lung disease caused by exposure to cotton dust in inadequately ventilated working environments.It commonly occurs in workers who are employed in yarn and fabric manufacture industries'

  • Idiopathic pulmonary fibrosis'Idiopathic pulmonary fibrosis: Scarring throughout the lungs without an identifiable cause.'

COPD can also be caused by prolonged exposure to certain dusty environments. For example, many people develop COPD after working in the coal mining industry and being exposed to high levels of respirable coal dust.
Among people over 70 who have never smoked, women make up 85 percent of those with COPD. This appears to be tied to decreases in estrogen as women age. Female mice that had their ovaries removed to deprive them of estrogen lost 45 percent of their working alveoli from their lungs. Upon receiving estrogen, the mice recovered full lung function. Two proteins that are activated by estrogen play distinct roles in breathing. One protein builds new alveoli, the other stimulates the alveoli to expel carbon dioxide. Loss of estrogen hampered both functions in the test mice. (Massaro & Massaro, 2004).

Angina Pectoris:
One 4-month double-blind placebo-controlled study of 200 individuals with heart disease found that the combination of nitroglycerin and NAC significantly reduced the incidence of heart attacks and other severe heart problems.10 NAC alone and nitroglycerin alone were not as effective. The only problem was that the combination of nitroglycerin and NAC caused severe headaches in many participants.

Mucolytic therapy:
mucolytic agent:
A mucolytic agent is any agent which dissolves thick mucus to help relieve respiratory difficulties. (hydrolyzing glycosaminoglycans: tending to break down/lower the viscosity of mucin-containing body secretions/components).
The viscosity of mucous secretions in the lungs is dependent upon the concentrations of mucoproteins, the presence of disulfide bonds between these macromolecules and DNA.
Inhaled acetylcysteine is indicated for mucolytic "mucus dissolving" therapy as an adjuvant in respiratory conditions with excessive and/or thick mucus production.

Such conditions include:
  • Emphysema
  • Bronchitis
  • Tuberculosis'Tuberculosis(abbreviated as TB for tubercle bacillus or Tuberculosis) is a common and deadly infectious disease caused by mycobacteria, mainly Mycobacterium tuberculosis.'

  • Bronchiectasis' Bronchiectasis : is a disease that causes localized, irreversible dilatation of part of the bronchial tree. Involved bronchi are dilated, inflamed, and easily collapsible, resulting in airflow obstruction and impaired clearance of secretions'

  • Amyloidosis' Amyloidosis refers to a variety of conditions in which amyloid proteins are abnormally deposited in organs and/or tissues, causing disease'

  • Pneumonia.


  • Unpleasant physical effects following the heavy use of alcohol.
  • A letdown, as after a period of excitement.
  • A vestige; a holdover: hangovers from prewar legislation.

Cysteine, which is available as the over-the-counter supplement N-acetylcysteine (NAC), is known to assist in processing acetaldehyde, best taken while already drinking and/or before going to bed.
N-acetylcysteine (NAC) is known to assist in processing acetaldehyde in the body and therefore can help to relieve hangover symptoms.

Acetylcysteine taken together with vitamin C and B1 can be used to prevent and relieve symptoms of Veisalgia'hangover following ethanol (alcohol) consumption'.
The claimed mechanism is through scavenging of acetaldehyde, a toxic intermediate in the metabolism of ethanol.

Egg yolk is also rich in cysteine, and it is notable that many hangover folk remedies or morning-after breakfasts incorporate eggs.