Drug Interaction Report

Garlic has been found in some studies to lower blood pressure and may theoretically potentiate the effects of hypotensive agents. A meta-analysis of 11 randomized, placebo-controlled studies showed a mean decrease of 4.6 mmHg for systolic blood pressure and no significant effect for diastolic blood pressure in subjects treated with garlic (most often garlic powder 600 to 900 mg/day, providing 3.6 to 5.4 mg of the active component allicin) compared to placebo. In the subgroup analysis of studies where subjects had a mean baseline blood pressure in the hypertensive range (SBP 140 mmHg or higher; DBP 90 mmHg or higher), mean decrease associated with garlic was 8.4 mmHg and 7.3 mmHg, respectively, for systolic and diastolic blood pressure. There have been no reports of clinical hypotension associated with concomitant use of garlic and antihypertensive agents.