Comparison guide
Which garlic supplement should you take?
All three come from the same bulb, but the evidence does not transfer evenly between them. The blood-pressure and cholesterol trials mostly used aged garlic extract or garlic powder, while allicin products rest on one cold trial and black garlic on a few small studies. What matters is whether the form you buy is the form that was tested.
The options, compared
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Garlic Extract | Moderate evidence | Modest blood-pressure effect | In people with hypertension, aged garlic extract lowered systolic pressure by about 8.3 mmHg over 8–12 weeks, typically at 1.2 g/day; cholesterol drops are real but modest. It is largely odourless, but it inhibits platelets and lowers some drug levels, so check with warfarin or protease inhibitors. | View |
| Allicin (Stabilized) | Limited evidence | Not worth the premium | The cold-prevention case rests on a single trial that has never been replicated, and the antimicrobial activity seen in culture is not achievable in blood. Products state an allicin yield rather than a content, so what you actually get varies. | View |
| Black Garlic | Limited evidence | Least evidence of the three | Gentle on the stomach, but its human trials are few, small or uncontrolled, and the one controlled trial showed no clear drop in standard cholesterol values. The stronger garlic evidence comes from powdered or aged garlic and transfers only loosely. | View |
Our verdict
If you want garlic for blood pressure, aged or standardised garlic extract is the form with the trials, and the effect is modest and mainly seen in people who are actually hypertensive. Skip stabilised allicin for colds, and treat black garlic as a food rather than a treatment. All three affect platelets to some degree, so take care with anticoagulants and before surgery.