The Health Benefits of Allicin

Allicin is a compound produced when garlic is crushed or chopped. Available in dietary supplement form, it's been found to reduce inflammation and offer antioxidant benefits.

Fresh garlic contains an amino acid called alliin. When the clove is crushed or chopped, an enzyme, alliinase, is released. Alliin and alliinase interact to form allicin, which is considered the major biologically active component of garlic.

Taking allicin supplements is said to help with a number of health problems, as well as fight major diseases like heart disease and cancer. In alternative medicine, allicin is said to protect against the following health problems:

• atherosclerosis 
• diabetes 
• high blood pressure 
• high cholesterol 

In addition, allicin supplements are sometimes used to enhance exercise performance. 

Many scientific studies have shown that the allicin in garlic may offer a variety of health benefits, such as better blood pressure control and prevention of atherosclerosis. While research on the specific health effects of allicin is fairly limited, there's some evidence that using allicin supplements may offer certain beneficial effects. Here's a look at several findings from the available research on allicin:

Several studies have shown that allicin may help lower cholesterol levels. In a small, early study published in the Journal of the American College of Nutrition, 46 people with high cholesterol were placed on a low-fat diet and assigned to 12 weeks of treatment with either a placebo or enteric-coated garlic powder tablets designed to deliver 9.6 mg of allicin.

At the end of the study, the 22 participants given garlic supplements showed a significantly greater reduction in total cholesterol and LDL ("bad") cholesterol compared to members of the placebo group. Allicin also did not significantly increase levels of HDL ("good") cholesterol. 

A 2013 updated meta-analysis of research found compounds in garlic help to reduce total cholesterol and LDL cholesterol when taken for at least two months and is associated with a 38 percent reduction in the risk of coronary events at 50 years of age.

Research suggests that allicin may help regulate blood pressure and may be as effective as medication for treating hypertension.

In a 2013 clinical trial performed in Pakistan, 210 patients with high blood pressure were given between 300 mg and 1,500 mg garlic tablets, a placebo, or the beta-blocker atenolol. Subjects given garlic showed clinically significant reductions in systolic and diastolic blood pressure over both the placebo and atenolol groups.

This study confirmed earlier animal studies showing allicin's blood-pressure-lowering properties.

Allicin may help alleviate exercise-related muscle damage, according to a study published in the European Journal of Applied Physiology in 2008.

In the study, a group of athletes took either allicin supplements or a placebo for two weeks before (and two days after) a treadmill-based workout. Results revealed those given allicin experienced less muscle soreness after their workout (compared to those given the placebo).

Side effects of allicin-containing supplements including diarrhea, heartburn, gas, and nausea.

Due to the lack of clinical trials testing the effects of garlic supplements, little is known about the safety of long-term or regular use of such supplements or how it might interact with prescription or over-the-counter medications.

Since allicin may also increase the risk of bleeding, it's crucial to avoid allicin-containing supplements prior to undergoing surgery. If you're currently using blood-thinning medications or supplements such as warfarin (Coumadin®), aspirin, ginkgo, or vitamin E, talk to your doctor before taking allicin-containing supplements. 

Allicin and garlic supplements should not be taken with blood pressure medications, as they can lower blood pressure. In addition, garlic may lower blood sugar and should be used with caution in people with diabetes who are taking anti-diabetic drugs.

Also keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

Allicin supplements are sold as tablets and supplements, and are labeled either garlic or allicin. There is no standard recommended dose for allicin.

A single garlic clove has about 5 mg to 18 mg of allicin. In research, doses between 300 mg and 1,500 mg of garlic have been studied.

A 2018 review of garlic and allicin supplements found the supplements were less effective than fresh garlic, and enteric-coated supplements were less bioavailable than non-coated supplements.

As a supplement, it is sold as both allicin and garlic. Which there may be some allicin present in garlic supplements, the dose varies depends on its preparation. Allicin supplements contain a more bioavailable source.

When selecting a brand of supplements, look for products that have been certified by Consumer Labs, The U.S. Pharmacopeial Convention, or NSF International.

What is the difference between allicin and garlic supplements?

While garlic supplements may contain some degree of allicin, allicin supplements contain a more bioavailable source of allicin.

Can allicin treat a yeast or fungus infection?

Alternative health proponents have long recommended the use of garlic in the treatment of vaginal yeast infections, by placing a pierced clove internally. According to the National Institutes of Health, allicin is a natural anti-fungal agent and the allicin found in fresh garlic may help to treat vaginal yeast infections, candida overgrowth, athletes foot, and other fungal infections.