N-Acetylcysteine Health Benefits, Properties, and Uses

N-Acetylcysteine, or NAC, is a thiol-containing amino acid that is oxidized in the human body to form cysteine. As a non-essential amino acid that also contains sulfur, cysteine plays an important health role in building and synthesizing proteins, detoxifying harmful free radicals and performing other metabolic functions. ^1,2
 
N-Acetylcysteine is found in minute quantities in most proteins but is not found directly in food. However, the human body requires high protein foods in order to convert NAC to cysteine. Cysteine is then made into glutathione which is a powerful antioxidant.¹
 
Cysteine is unique among natural amino acids as it contains a thiol group that undergoes reduction of oxidation making it crucial in forming protein structures.

N-Acetylcysteine Health Uses and Health Benefits
 
As an antioxidant, cysteine is highly effective at fighting free radicals which are harmful compounds that damage cell membranes and DNA. Researchers suspect N-Acetylcysteine health benefits play a vital role in treatment and prevention of cancer, heart disease and may have an effect on slowing aging. ¹
 
Cysteine also composes part of the antioxidant glutathione that is effective for treating AIDS, chronic obstructive pulmonary disease (COPD) and N-Acetylcysteine for PCOS (polycystic ovary syndrome). ^1,3
 
N-Acetylcysteine health benefits are important contributors to energy metabolism, a strong source of sulfur and is a main protein builder for healthy skin, hair and nails. Cysteine deficiency is a leading cause of premature baldness. ^1,2
 
N-Acetylcysteine health benefits include an important role in converting proteins from food into cysteine that the body needs for energy and disease fighting. While cysteine is not directly found in food as the body makes it, healthy foods with high protein content include: 

• Ricotta, cottage cheese and yogurt
• Pork, chicken, duck and turkey
• Wheat germ, granola and oat flakes

Other N-Acetylcysteine health benefits include natural treatment for:

• Chronic Obstructive Pulmonary Disease (COPD) - COPD is an all-encompassing term for many respiratory ailments where the lungs are blocked and unable to properly function. NAC converts cysteine into glutathione that works to break down mucus and helps to clear airways.
• Emphysema - Emphysema is one form of COPD that causes over-inflation of the alveoli or air sacs in the lungs. NAC boosts levels of glutathione that helps to relieve swollen alveoli and assist better breathing.
• Polycystic Ovary Syndrome - NAC is shown to help balance estrogen and progesterone levels that contribute ovarian cysts. N-Acetylcysteine for PCOS is an effective natural health supplement.
• Lung Cancer - N-Acetylcysteine converts cysteine proteins into glutathione that plays a crucial part in detoxifying free radicals that a primary cause of lung cancer.
• AIDS (HIV) - N-Acetylcysteine is thought to be helpful in weight gain to AIDS sufferers. NAC converts to glutathione that has shown to improve weight loss that’s a common side effect of AIDS.
• Blepharitis - Blepharitis is a common eyelid inflammation caused by bacterial infection. Studies show that NAC assists in breaking up fluorescein that is a contributor to blepharitis.

N-Acetylcysteine Side Effects and Precautions
 
The most common N-Acetylcysteine side effects are skin rash, nausea, vomiting and fever. N-Acetylcysteine side effect may also cause allergic reactions in some people and may have an adverse effect on asthma sufferers.¹
 
There are toxic forms of cysteine that should be avoided. They include D-Cysteine, D-cysteine and 5-methyl cysteine.¹

References

1. http://umm.edu/health/medical/altmed/supplement/cysteine
2. https://pubchem.ncbi.nlm.nih.gov/compound/L-cysteine#section=Top
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3044191/