Consuming one clove of garlic per day, or 3–6 grams (g), can reduce cholesterol levels by 10%, some research shows. Garlic and garlic supplements can also have other health benefits and some mild side effects.

Multiple studies claim that garlic reduces cholesterol. However, the evidence is not yet conclusive. The effectiveness of garlic on cholesterol levels depends on the type and preparation.

The body transports cholesterol around a person’s blood in two proteins called lipoproteins.

Low-density lipoproteins (LDL) make up most of a person’s cholesterol. High levels of LDL raise the risk of heart-related health conditions. High-density lipoproteins (HDL) absorb cholesterol. High levels of HDL lower the risk of heart-related health conditions.

This article examines whether garlic reduces cholesterol levels, which types are best, its side effects, and how long it takes to lower cholesterol.

Garlic cloves, which some studies suggest can lower cholesterol.Share on Pinterest

There has been lots of research into the effects of garlic on a person’s blood cholesterol. Several studies have suggested that garlic intake can reduce cholesterol levels. However, other studies have suggested garlic has no effect on lowering cholesterol.

Of the studies that showed garlic could lower cholesterol, opinions differ on which types of garlic are most effective.

Raw garlic bulbs contain a substance called alliin. Alliin turns into a sulfur-based compound called allicin when exposed to the air.

Allicin gives garlic its distinctive smell. Studies have associated allicin with numerous health benefits, including;

The food preparation method affects how much allicin is present. Different garlic products will lower cholesterol levels at different rates.

Learn more about the difference between HDL and LDL cholesterol.

Common types of garlic include:

  • Black garlic extract: A garlic with a deep brown or black color. People produce black garlic by aging garlic cloves in low heat and high humidity for several weeks.
  • Kyolic garlic extract: A type of aged garlic extract (AGE). Kyolic garlic is an odorless extract that people age for up to 20 months without heat.
  • Raw garlic: Garlic in its natural form.
  • Garlic powder: A spice made from dehydrated raw garlic.
  • Garlic oil: A seasoning made by steaming crushed garlic.
  • Garlic tablets: These may contain garlic powder or oil and are usually odorless.

Scientific opinions vary on which type of garlic is most effective for reducing cholesterol.

Research suggests that AGE may give the most consistent benefits in reducing total cholesterol levels than other garlic types. It is possible garlic powder and oil still have a beneficial effect on cholesterol levels.

A 2020 review mentions several studies that show aged black garlic extract reduced LDL cholesterol and elevated HDL cholesterol (HDL) levels. In these studies, participants took 300 milligrams (mg) or 6 grams (g) of aged black garlic extract twice daily for 4 or 12 weeks.

Other studies suggest that crushed garlic powder is ineffective in lowering blood cholesterol levels. The study authors attributed this to a possible loss of allicin during processing. For this reason, researchers preferred raw garlic during studies of cholesterol levels.

Learn more about the benefits of garlic here.

As with any drug or dietary supplement, there can be some side effects. These are typically mild and tend to occur when people consume high doses of raw garlic. Aged garlic extract may not produce these side effects due to its preparation.

A 2016 clinical review found that common side effects of garlic include the following:

If someone has a garlic allergy, touching garlic may cause contact dermatitis. Contact dermatitis is a type of eczema that causes a person’s skin to become itchy, dry, or cracked.

In rare cases, some people with garlic allergies may experience anaphylaxis, which can be life threatening.

Learn how to get rid of garlic breath here.

A small 8-week study suggested that consuming 20 g of garlic and 1 tablespoon (tbsp) of lemon juice daily lowered blood cholesterol levels and blood pressure. It is important to note that one garlic clove is approximately 6 g.

Research has shown that half to 1 clove of garlic per day can lower a person’s cholesterol levels by approximately 10%. This is equivalent to 3–6 g of garlic per day.

Garlic tablets are also available, although the beneficial effects can vary by manufacturer. A 2018 study found that taking tablets equivalent to 2 g of crushed raw garlic could have benefits.

The ability of allicin in garlic to enter a person’s bloodstream (bioavailability) also varies depending on the supplement used and what a person consumes it with.

Some garlic tablets have a polymer coating, known as an “enteric coating,” that slows digestion. The same 2018 study mentioned above suggests that the allicin bioavailability of enteric-coated garlic tablets is more variable than non-enteric-coated tablets.

The study also found that taking enteric-coated garlic tablets with a high protein meal greatly reduced allicin bioavailability.

Learn more about supplements in our dedicated hub here.

Generally, garlic has few major drug interactions. Studies show garlic may interact with anti-coagulation medication, such as warfarin.

However, a systematic review suggested this interaction may be insignificant.

Learn more about drug interactions here.

According to the Centers for Disease Control and Prevention (CDC), the following foods can help to prevent high cholesterol levels:

People should avoid foods high in saturated fat, such as cheese, fatty meats, and dairy desserts.

Learn more about other cholesterol-lowering foods.

Garlic supplements are not a replacement for medication and may not be as effective.

People who wish to manage a health condition, such as high cholesterol, should discuss any intended diet changes with a healthcare professional.

Here are some frequently asked questions about garlic and cholesterol.

How much garlic should a person take to lower cholesterol?

Research suggests that daily consumption of 2–20 g of garlic may help to reduce cholesterol. However, more research is necessary to determine the ideal dosage of garlic to reduce cholesterol.

What is the best way to eat garlic to reduce cholesterol?

People can consume garlic in various forms to reduce cholesterol levels, including:

  • garlic extract
  • raw
  • powder
  • tablets
  • oil

How long does it take for garlic to lower cholesterol?

Studies have shown that taking garlic for 8 weeks improves cholesterol levels. A dose of 6 g of garlic twice daily reduced total cholesterol levels over 4–12 weeks. 6 g of raw garlic is approximately one clove.

Does garlic lower cholesterol and blood pressure?

In clinical trials, garlic has lowered blood pressure without notable side effects.

Some research in clinical trials has shown that garlic lower cholesterol levels. Consumption of garlic can result in side effects, although these are often mild.

Scientific opinion varies on which form of garlic reduces cholesterol most effectively. Some evidence suggests that raw garlic and aged black garlic produce the best reduction in a person’s cholesterol levels.

While garlic may aid in the reduction of high cholesterol levels, certain lifestyle habits and diets will help a person maintain their cholesterol levels. A person should always consult a healthcare professional about high cholesterol levels.

Learn more about cholesterol in our dedicated hub here.