What it's actually good for
Aged garlic extract (AGE) is a specific preparation where raw garlic is aged in a controlled process for 12-20 months, converting the pungent and unstable allicin into gentler, more bioavailable organosulfur compounds — primarily S-allylcysteine (SAC). This distinction matters: the cardiovascular evidence is specifically for aged garlic extract, not for garlic oil, garlic powder, or raw garlic cloves. For blood pressure, a meta-analysis of RCTs shows that AGE at 600-2400 mg/day produces clinically meaningful reductions of approximately 7-9 mmHg systolic in people with hypertension, which is comparable to some first-line antihypertensive medications in magnitude. In normotensive individuals, the effect is minimal, suggesting AGE works primarily by correcting pathological blood pressure elevation. For cholesterol, multiple trials show modest reductions in total and LDL cholesterol (roughly 10-12%), which is meaningful though not a replacement for statins in high-risk patients. The immune evidence is weaker, with only a few small trials suggesting enhanced NK cell activity and reduced cold severity. AGE earns a B because the cardiovascular RCTs are reasonably sized and consistent, but the effect sizes are moderate and the best evidence is concentrated in hypertensive rather than general populations.