S-Allyl-L-cysteine is a sulfur-containing amino acid derivative naturally present in garlic (Allium sativum). It forms via enzymatic hydrolysis of gamma-glutamyl-S-allylcysteine during garlic aging or extraction processes. The compound demonstrates antioxidant activity by scavenging reactive oxygen species, anti-inflammatory effects through modulation of NF-kB pathways, and potential cardioprotective and neuroprotective benefits in preclinical studies. It is stable under physiological conditions and contributes to the health-promoting properties of aged garlic extracts.