Eleutheroside C is a lignan glycoside (syringaresinol 4,4'-diglucoside) isolated from the roots of Eleutherococcus senticosus (Siberian ginseng). As a key bioactive compound, it contributes to the plant's adaptogenic effects. Used in traditional medicine to help the body resist stress and fatigue, support immune function, and enhance physical endurance. Often included in herbal formulations and supplements to improve mental clarity, reduce exhaustion, and boost overall vitality. Studied for its antioxidant properties that may protect cells from oxidative damage, as well as potential neuroprotective effects against neuronal degeneration.