Pharmacological and Therapeutic Potential of Garlic ( Allium sativum ): Integrating Phytochemistry, Molecular Mechanisms, and Clinical and Preclinical Evidence

Garlic ( Allium sativum ) is a medicinal plant with diverse pharmacological properties and therapeutic potential in metabolic, cardiovascular, hepatic, immune, inflammatory, infectious, and neoplastic disorders. However, comprehensive integration of clinical and preclinical evidence remains limited. This review synthesized randomized controlled trials, crossover studies, therapeutic clinical investigations, and experimental animal studies evaluating garlic supplementation. Allicin was identified as the principal intermediate precursor generating numerous bioactive organosulfur compounds. Clinical evidence demonstrated reductions in systolic blood pressure of 5.2%–10.5% and diastolic blood pressure of 4.0%, decreases in LDL cholesterol of 11.8%–14.2% and total cholesterol of 7.6%–14.2%, and increases in HDL cholesterol of 11.5%. Fasting glucose decreased by 7.01 mg/dL, and HbA1c by 0.66%. Inflammatory markers, including TNF‐α and C‐reactive protein, declined by up to 24.7%, whereas antioxidant capacity increased. Preclinical studies demonstrated reduced tumor growth, improved renal function, enhanced epithelial regeneration, and increased survival in experimental infection models. Garlic demonstrates consistent therapeutic benefits across multiple conditions. Nevertheless, additional high‐quality, large‐scale clinical trials are required to establish optimal dosing, long‐term safety, and clinical efficacy.