Allium sativum, or garlic, is an herb with a multitude of medicinal uses. It has been used for centuries for its ability to boost immune function and kill harmful microbes and is also popular in cooking due to its bold flavor. Added to foods for its healing properties, or taken in supplements in the form of capsules, tablets and extracts, garlic is generally recognized as safe by the Federal Drug Administration. However, it may still cause unwanted side effects in some instances. Understanding the potential side effects of garlic tablets is vital for the health and safety of consumers using the herb.
Despite its potential benefits for digestive health, garlic can cause gastrointestinal upset in some people. Gastrointestinal symptoms are generally associated with raw garlic and may include indigestion, gas, belching, mild cramping and abdominal bloating.
Using garlic in its cooked form may help prevent gastrointestinal side effects like indigestion. Taking an antacid along with garlic tablets may also reduce symptoms. If indigestion is severe, try taking your supplements in divided doses or talk to your doctor about lowering your daily dose of garlic.
Uncontrollable bleeding is a potentially serious side effect of garlic tablets. Due to its ability to prevent platelet aggregation, or blood clotting, garlic may increase the chances of bleeding, particularly when taken with blood thinning medicines. If you have an upcoming surgery, you should discontinue garlic supplements about 7 days before the procedure.
To reduce bleeding risks, avoid taking garlic with blood thinning medications, non-steroidal anti-inflammatory drugs and herbs such as turmeric or ginger. Avoid use if you have a history of blood clotting disorders or hemorrhagic stroke, and stop using garlic tablets at least one week prior to surgery.
Some garlic tablets may cause an increase in breath or body odor. Allicin, a compound in garlic, is responsible for both the herb's medicinal effects as well as its strong smell. Using garlic tablets or supplements that contain cooked or processed garlic may help prevent this side effect. While deodorized garlic supplements exist, these products may possess less potent healing properties than regular garlic.
Interactions between medications and herbs such as garlic are relatively common. According to Drugs.com, garlic tablets may cause negative interactions with some blood sugar medications, protease inhibitors and blood thinners. Because they have a thinning effect on blood, non-steroidal anti-Inflammatory drugs, such as aspirin, naproxen and ibuprofen should be used with caution when taking garlic tablets.