Olesta Tab contains the active component olmesartan medoxomil, which belongs to the class of angiotensin II receptor blockers. The medicine is used to treat high blood pressure (hypertension) in both young and old persons. The principal ingredient acts by inhibiting the action of a hormone called angiotensin II, which constricts blood vessels and elevates blood pressure. By inhibiting the effect of this hormone, it helps to relax and broaden the blood vessels, allowing blood to flow more easily and lowering blood pressure. The drug comes in tablet form and should be taken exactly as suggested by the doctor for effective results.