Rauwolfia is considered an important therapeutic option for patients with mild to moderate essential hypertension not improved by lifestyle changes. Rauwolfia alkaloids bind irreversibly to catecholamine storage granules in neurons, primarily those in the mid-brain autonomic centres and cells in the adrenal medulla, causing depletion of catecholamines and 5-HT from those granules. As a result there is a lessening of systemic sympathetic tone leading to reduction in blood pressure. This entirely central mechanism of action of reserpine has no direct effect on the heart or blood vessels.

Reserpine at a low dose (0.05–0.25 mg/day) in combination with a thiazide diuretic was the first therapeutic combination with reduced incidence of adverse effects such as chronic hypertension and stroke in large double-blind trials. The longer half-life and hence once-daily dosing of reserpine has been an added advantage. High-dose reserpine (0.5–1 mg/day), on the other hand, is associated with depression, Parkinsonism, impotence and peptic ulcer. Low-dose reserpine is extremely safe and less expensive than any synthetic antihypertensive drug. The whole plant is shown to have better overall efficacy than isolated reserpine.