Synopsis

Source of validity: Scientific
Rating (out of 5): 2

Cysteine is a conditionally essential amino acid that serves as a precursor to glutathione, a major intracellular antioxidant. Its use in autoimmune disorders is grounded in its role in redox balance and immune modulation, though direct evidence is modest. Some preclinical and small clinical studies indicate that cysteine supplementation (often as N-acetylcysteine, or NAC) can help restore glutathione levels and reduce oxidative stress, which is elevated in many autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). For example, a small randomized controlled trial (RCT) in SLE patients showed that NAC improved disease activity and reduced T-cell dysfunction, likely via glutathione restoration and modulation of mTOR signaling (Perl et al., Arthritis Rheumatol. 2015). Animal studies also support an immunomodulatory effect of cysteine or NAC supplementation. However, the overall quality and quantity of human clinical evidence remain limited, and larger, well-controlled trials are needed to establish efficacy, optimal dosing, and safety long-term. Current scientific support for cysteine’s use in autoimmune disease management is therefore considered preliminary, with more robust evidence required before widespread clinical adoption.

More about Cysteine
More about Autoimmune Disorders

Other ingredients used for Autoimmune Disorders

Other health conditions supported by Cysteine

Products containing Cysteine