Alfalfa (Medicago Sativa): Phytochemistry, Pharmacological Activities, Therapeutic Applications, and Adverse Effects – A Comprehensive Review

Medicago sativa L., universally referred to as Alfalfa or Lucerne, is a deep-rooted perennial flowering legume belonging to the family Fabaceae. Long celebrated globally as the —Queen of Forages‖ owing to its unparalleled primary nutrient density, Alfalfa has firmly transcended its agronomic foundations to assume an important standing in contemporary pharmaceutical evaluation and pharmacognostic standardization. This comprehensive review synthesizes the extensive scientific literature regarding the botanical taxonomy, intricate chemical profile, diverse pharmacological landscape, evidence-based clinical utilities, and safety boundaries of M. sativa. Extensive phytochemical profiling across decades reveals a structural kaleidoscope of specialized secondary metabolites, most prominently triterpenoid saponins, flavones, isoflavones, coumestans, alkaloids, phytosterols, and unique non-protein amino acids. Modern pharmacological screening has validated its dynamic therapeutic properties, demonstrating robust hypocholesterolemic, anti-diabetic, antioxidant, anti-inflammatory, neuroprotective, hepatoprotective, antimicrobial, and estrogenic activities. Clinically, specialized preparations of Alfalfa hold distinct potential in the complementary management of metabolic syndromes, cardiovascular diseases, atherosclerosis, postmenopausal symptoms, and rheumatoid arthritis. Paradoxically, the safety evaluation of M. sativa demands strict scientific vigilance; the presence of the toxic antimetabolite L-canavanine has been unequivocally linked to the induction and clinical reactivation of systemic lupus erythematosus (SLE) and related autoimmune phenotypes. This manuscript aims to serve as a definitive baseline compilation, balancing the remarkable therapeutic efficacy against documented adverse liabilities to direct future clinical trials and rational formulation engineering.