What is the difference between L-cysteine and L-cystine?
                                
                                
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                                    4 min read                                
                            
                                L-Cysteine is a semi-essential amino acid that our body can synthesize from methionine, but L-cystine is its dimerized, oxidized form. These two related but distinct molecules play critical roles in biological functions, from building proteins to defending against oxidative stress. Understanding the difference between L-cysteine and L-cystine is essential for grasping their unique functions in human health.