If you are currently being treated with any of the following medications, you
should not use garlic supplements without first talking to your healthcare
Garlic may exaggerate the activity of
medications that inhibit the action of platelets in the body. Examples of such
medications include indomethacin, dipyridamole, and aspirin.
There have been reports of a
possible interaction between garlic and warfarin that could increase the risk of
bleeding in people taking this blood thinning medication. Therefore, when taking
medications that may thin the blood, such as aspirin and warfarin, you should
refrain from consuming large quantities of garlic, either fresh or commercially
When used with a class of medications for
diabetes called sulfonylureas, garlic may lower blood sugar considerably.
Medications from this class include chlorpropamide, glimepiride, and glyburide.
When using garlic with these medications, blood sugars must be followed closely.
Garlic may reduce blood levels of protease
inhibitors, a medication used to treat people with the human immunodeficiency
virus (HIV), including indinavir, ritinavir, and saquinavir.
It is thought that garlic may behave similarly to a
class of cholesterol lowering medications called statins (such as atorvastatin,
pravastatin, and lovastatin) and to a class of blood pressure lowering
medications called ACE inhibitors (including enalapril, captopril, and
lisinopril). It is not known, therefore, whether it is safe to take this
supplement in large quantities with these medications or not. This possible
interaction has never been tested in scientific studies.