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Garlic has long been touted as an alternate remedy for a number of health issues. It’s credited with providing many benefits, from lowering cholesterol to possibly preventing cancer. Eating more garlic can seem like a no-brainer.

Its evident ability to help with cholesterol might be desirable to people taking HIV medications, which can increase cholesterol. There’s also some evidence that garlic may have antimicrobial and immune-boosting effects.

Before crushing, chopping, and adding this herb into your diet, be aware that garlic has the potential to interact negatively with medications, including certain antiretrovirals.

Find out the risks and benefits of garlic, and discover how one of its chemicals can end up doing more harm than good.

Garlic has been used for centuries to speed up healing and fight bacteria and viruses.

In ancient times, garlic was used as a cure-all for many ailments, including stomachaches, infections, and coughs.

According to a 2014 literature review, modern science has documented garlic’s effects on immune system improvement, cardiovascular disease, and more.

When raw garlic is crushed, it produces a chemical compound called allicin. This compound gives garlic its strong odor. It’s also partly responsible for the herb’s germ-fighting and health-promoting properties.

According to the National Center for Complementary and Integrative Health (NCCIH):

Importantly, the NCCAM also notes that garlic can interfere with the action of certain medications.

Garlic can affect how fast the body breaks down drugs, including some used to treat HIV. If a person takes garlic with a vulnerable medication, they could end up with too much or too little of the drug in their bloodstream. That can affect how well HIV treatment works for them.

A 2017 literature review concluded that some forms of garlic significantly decrease the levels of certain antiretrovirals and shouldn’t be used by people living with HIV.

Protease inhibitors

In a small 2002 study published in Clinical Infectious Diseases, researchers studied the effects of garlic on the HIV drug saquinavir. They found that taking garlic supplements with saquinavir caused the drug levels in the bloodstream to drop significantly, by 30 to 40 percent.

The researchers recommended that people exercise caution if combining garlic with saquinavir when used as a sole protease inhibitor.

In a 2010 test-tube study involving animals, aged garlic extract inhibited the activity of saquinavir. However, it enhanced the activity of darunavir, another protease inhibitor.

According to the prescribing information for Invirase, a brand-name version of saquinavir, co-administration of saquinavir and garlic capsules isn’t advised.

Other HIV medications

According to a 2017 study, people should also avoid garlic supplements if they take the following HIV medications:

  • non-nucleoside reverse transcriptase inhibitors (NNRTIs), which include efavirenz (Sustiva) and rilpivirine (Edurant)
  • dolutegravir (Tivicay)
  • maraviroc (Selzentry)
  • cobicistat-boosted elvitegravir

This is due to the possibility of drug interactions.

Talk with a healthcare provider

If any of the above medications are a part of a person’s HIV treatment regimen, they should talk with their healthcare provider about taking garlic supplements.

It may be safe for them to add garlic to their food, but their healthcare provider will be able to tell them if large amounts of garlic or garlic supplements may interfere with their HIV treatment.

In addition to potential drug interactions, garlic can cause side effects that might affect a person’s ability to take HIV treatments. Garlic’s side effects may also mimic some symptoms caused by HIV or AIDS.

Consider asking a healthcare provider how to tell the difference between garlic’s effects and symptoms caused by HIV or AIDS.

Side of effects of garlic include:

Because garlic can thin the blood, it may cause bleeding problems in some people. A person should be mindful of their garlic intake if they:

If a person is in one of the scenarios listed above, it may be a good idea for them to talk with their doctor about using garlic supplements or consuming foods that contain high amounts of garlic.

A person living with HIV should let their healthcare provider know about all the drugs and herbs they take, even those bought without a prescription. A healthcare provider can let them know if raw or bottled garlic might help their health and whether it can interfere with their HIV treatment plan.

A pharmacist is also a great resource to ask about drug and supplement interactions.