1:5 – 50%. Gotu kola is extensively used in Ayurvedic medicine for increasing mental capacity and decreasing mental aging. Research indicates that Centella has the tendency to modulate both internal (pathological) and external (neuro-toxic) oxidative brain impairment, and can be used to halt further damage. While this herb encourages cognition, it also has a role in vascular health as a cardio-protective, preventing injury to the heart muscle in the case of heart attack. Dosage: 20-60 drops up to 4x day.