Heart Disease Channel
Topics
Medications
Quicklinks
Related Channels
Garlic Side Effects
Some people think that because garlic is a "natural" product, it does not have any side effects. This is simply not true. In most cases, garlic side effects are merely bothersome, and may include things such as heartburn, gas, and nausea. However, potentially serious side effects of garlic are also possible, such as unusual bruising or bleeding, a hemorrhagic stroke, or allergic reactions.
Even though garlic is natural, it is not always free of side effects. For most people, these garlic side effects are merely bothersome. However, garlic can sometimes cause serious side effects as well, especially when taken at higher dosages, such as when garlic is used medicinally.
Many people may experience gastrointestinal side effects from garlic, such as:
- Garlicky breath or body odor
- Heartburn or indigestion
- Mouth irritation or burning
- Gas
- Nausea
- Vomiting
- Diarrhea.
These bothersome side effects are more commonly seen when raw garlic is used. "Odorless" garlic supplements are available, but there is some concern that these products may not contain enough of the active components of garlic to provide any benefit.
There are a number of side effects with garlic that you should report to your healthcare provider and which might indicate that you should stop taking it. These include but are not limited to:
- Any unusual bruising or bleeding (garlic can increase the risk of bleeding)
- Black, tarry stools; bright red blood in the stool; or vomiting of blood (signs of gastrointestinal bleeding)
- Signs of a hemorrhagic stroke (bleeding in the brain), such as:
- Vision or speech changes
- Weakness or numbness in an arm or leg
- Severe headache
- Signs of an allergic reaction, such as:
- An unexplained rash
- Hives
- Itching
- Unexplained swelling
- Wheezing
- Difficulty breathing or swallowing.
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD