Synopsis

Source of validity: Scientific
Rating (out of 5): 3

L-cysteine is an amino acid that serves as a precursor to glutathione, a major antioxidant in the body, and is also involved in the synthesis of proteins and other biomolecules. Its use to support the mucus membranes—such as those lining the respiratory tract—is primarily linked to its role in mucolytic therapy, particularly in the form of its derivative, N-acetylcysteine (NAC). Scientific studies have shown that NAC can reduce the viscosity of mucus, making it easier to clear from the airways in conditions like chronic bronchitis or cystic fibrosis. This mucolytic action helps maintain the health and function of respiratory mucus membranes. L-cysteine itself is less commonly used directly for this purpose, but because it is a precursor to NAC and glutathione, it is sometimes included in supplements aimed at supporting respiratory health and, by extension, mucus membrane integrity. Clinical trials and reviews support the efficacy of NAC in decreasing mucus thickness and improving symptoms in respiratory illnesses, though direct evidence for L-cysteine is less robust. Overall, the use of L-cysteine for mucus membrane support is grounded in scientific rationale, though the strength of evidence specifically for L-cysteine (as opposed to NAC) is moderate rather than strong.

More about l-cysteine
More about Mucus Membranes

Other ingredients that support Mucus Membranes

Other body systems supported by l-cysteine

Products containing l-cysteine

Nature's Sunshine Free Amino Acids
Nature's Sunshine Mega-Chel
Nature's Sunshine Sunshine Heroes Whole Food Papayazyme
Nature's Sunshine Sunshine Heroes Probiotic Power
Nature's Sunshine Super Supplemental
Nature's Sunshine Super Supplemental (Without Iron)
Nature's Sunshine Super Trio
Nature's Sunshine VitaWave