Garlic: Uses, Health Benefits, Dosage, & Side Effects

What is Garlic?

Friends Garlic is a bulbous herb vegetable species in the onion genus Allium. Its scientific name is Allium sativum.

Onion, leek, Chinese onion, and shallot are some of the close its relatives.

It is native to Northeastern Iran and Central Asia, but spread to other regions of the world over 5000 years ago.

China is the largest producer of the garlic in the world and produces approximately 80% of the world’s supply.

It is rich in compounds like Allicin, Zinc, Calcium, and Sulfur that have antibiotic and antifungal properties.

The presence of organic sulfur compound Allicin in it, gives garlic its pungent smell.

Fresh garlic, its oil, or its powder is used in foods and beverages to add flavor.

It is very effective in preventing and treating many health-related problems.

By acting as a blood thinner, it enables proper flow in the blood vessels. It is commonly used in conditions like high levels of cholesterol, high blood pressure, hardening of the arteries (atherosclerosis), etc.

How Many Types Of Garlic Are There?

Friends there are about hundreds of varieties of garlic but approximately 70 of them are grown.

All these varieties can be categorized into two main groups. These are:

1) Hardneck Garlic

2) Softneck Garlic

1) Hardneck Garlic

These are considered to be the original cooking garlic that are evolved from wild garlic. The bulb of hardneck group has fewer clothes as compared to softneck group, generally less than ten.

Hardneck garlic is harder and takes longer time to mature. It is generally grown in cold climates. This group comes in a broader variety of colors as compared to softneck group.

Garlic of this group is easier to peel and have an intense flavor. It has woody and stiff stalk.

Hardneck garlic has following main types:

1) Asiatic Hardneck Garlic

This type mainly came from Korea. It has medium sized bulbs having four to eight cloves in each bulb. It can be stored very well with a shelf life of five to six months.

Cloves of Asiatic hardneck garlic are vibrantly colored. It is commonly used in Asian cooking to add flavor to the food.

2) Glazed Purple Stripe Hardneck Garlic

This type is native to Eastern Europe. The bulbs are medium sized with large stocky cloves. The cloves of this type are red-purple colored and striped with flashings of silver.

This type is particularly good for those who love good garlic taste but find the hot sensation associated with garlic unpleasant; it is due to the reason that it has a mild flavor and adds a gentle heat to the dishes.

Clove number in each bulb varies among cultivars and commonly ranges from six to twelve. It has a shelf life of around five to seven months

3) Marble Purple Stripe Hardneck Garlic

This type is native to Eastern Europe and Russia. Clove number in each bulb varies from four to eight. It has beautiful bulbs dappled with purple and white marks.

This hardneck garlic has a strong flavor and a shelf life of around seven months.

It is the best type to be used for making baked garlic.

4) Creole Hardneck Garlic

This type is widely grown in Southern United States and is well suited for warmer climates.

It has small to medium sized bulbs. The clove number in each bulb varies in between eight to twelve. The cloves have striking shades of red and purple.

Creole hardneck garlic has a delicate nutty flavor and is very popular in gourmet cuisine.

5) Middle Eastern Hardneck Garlic

This type is mainly grown in Middle East. It prefers warm growing conditions.  The bulbs of this type have a bumpy texture and can range in size. This plant grows to a medium height.

It has numerous cloves and multiple clove layers just like the silverskin group. But its cloves are more separated with rounded sides and curved inner surface whereas in silverskin goup cloves are flattened on the interior side with rounded corners.

6) Porcelain Hardneck Garlic

This type has large bulbs and contains the highest allicin content of all types. It has a moderate to strong intensity of flavor.

The number of cloves in each bulb varies from four to six. Its skin is smooth and thick occasionally with purple markings.   

7) Rocambole Hardneck Garlic

It is the most popular hardneck type for growing at home. It is hot and full of flavor that’s why it is chef’s favorite.

This hardneck garlic is high in sulfenic acid which is responsible for its chilli-like burning taste, but quickly disappears. It is regarded as the best flavored garlic.

Its cloves are tan or red-colored. It requires very cold winters to grow. It has a shelf life of six months.

8) Turban Hardneck Garlic

It gets its name from the top of its stalk that forms the shape of a turban. Its plant tends to be relatively short with broad and drooping leaves.

Number of cloves in each bulb is in between seven to eleven. Its bulbs are slightly flattened in shape with purple striped skins that split easily and get whiten during storage.

It has a short shelf life.

9) Purple Stripe Hardneck Garlic

This type is native to Republic of Georgia. It has a strong and rich quality of flavor, which becomes sweet when baked. Because of its sweetness it is used in making garlic ice cream.

Number of cloves in each bulb is in between eight to sixteen. 

Its bulbs are white in color with purple/pink coloring and striping. Bulbs are round globe and can be quite large.

It grows best in cooler climates.

2) Softneck Garlic

These are the garlic you mostly see in the grocery store. This is mainly due to the reason that it matures much faster than hardneck garlic and is perfect for commercial production purposes.

Softneck Garlic is more adaptive to a variety of climates and produces more bulbs per plant. This group usually has more cloves than hardneck group.

The cloves of this group are smaller in size. Softneck garlic has papery wrapping which is multilayered and creamy in color. This garlic has a shelf life of up to eight months.

These are easier to harvest, handle and clean as they generally don’t form scapes.

Softneck garlic has following main types:

10) Silverskin Softneck Garlic

It is little bit smaller than artichoke softneck garlic and is usually in tear-drop shape. It has off white or satiny white skins.

Number of cloves in each bulb is in between eight to forty. Cloves are arranged in three to five layers. It has a strong flavor.

This softneck garlic has a longest shelf life of all types of garlic and can be stored up to twelve months. It grows best in warm to hot summers and mild winters.

These are the garlic that you commonly seen displayed in a grocery store or farmer’s market.

11) Artichoke Softneck Garlic

Artichoke softneck is one of the best known and commonly grown garlic. Most of the commercial growers only grow this type of garlic because of its adaption to a wide range of growing climates and it matures early in the growing season.

Its bulbs are larger and have fewer cloves than silverskin softneck garlic. Number of cloves in each bulb is in between twelve to twenty.

Its bulbs tend to have flattened or teardrop shaped. It has a shelf life of ten months.

What Are The Uses And Health Benefits Of Garlic?

Friends, Garlic is rich in compounds like allicin, sulfur, zinc, etc. that have antifungal and antibiotic properties. It is also a good source of selenium, which is known to fight cancer.

In fact, for centuries, garlic has been suggested by ayurvedic and herbal doctors to be included in the daily diet because of its beneficial effects on health. Garlic is very effective in preventing and treating many health related problems. Main uses and health benefits of garlic are:

1) It may stabilize your blood pressure

Strokes and heart attacks are the biggest killers in the world. High blood pressure is one of the main causes of these diseases.  

Friends, garlic contains a sulfur compound called S-allyl cysteine which may lower your systolic blood pressure by 10 mm of Hg and diastolic pressure by 8 mm of Hg. Sulfur deficiency is one of the causes of high blood pressure and thus supplementing your body with sulfur compounds that can help control your blood pressure. (1)

2) Garlic can improve your cholesterol levels

Friends, LDL (Low density lipoprotein) and HDL (High density lipoprotein) are two types of cholesterol. Out of these two LDL is considered as bad cholesterol and HDL is considered as good cholesterol.   

High levels of LDL cholesterol in your body can increase the risk of heart diseases. Thus, it is very important to keep your cholesterol levels under control at all times.

A study has have shown that garlic extract supplements can help lower the LDL cholesterol in hypercholesterolemic males. It has also shown that garlic inhibited the synthesis of cholesterol in liver cells of rats. The study has also shown that water soluble compounds of garlic inhibited cholesterol synthesis by 20-60%. (2)

Thus, consuming 1-2 raw cloves of garlic daily can lower your LDL cholesterol.

3) It may regulate your blood sugar

High blood sugar levels for prolonged period may increase your risk of developing diabetes, obesity, blood pressure etc. So, you should include garlic in your diet if you are suffering from high blood sugar.

A study which was conducted on rats has shown that raw garlic had a profound effect in reducing the blood sugar levels whereas boiled garlic had little effect in reducing blood sugar levels. (3)

Thus if you consume 3-4 cloves of raw garlic, it may lower your blood sugar levels.

4) It may lower your risk of cardiovascular diseases

Studies have shown that garlic can lower your risk of cardiovascular diseases.

It has been proved by animal and human studies that garlic supplementation has the efficacy of cardiovascular protection as it reduces cardiovascular risk factors like blood pressure and total cholesterol; and has favorable effects on surrogate markers of atherosclerosis {like CRP (C-reactive protein), PWV (pulse wave velocity), and CAC (coronary artery calcium)}. (4)

Consuming one to two raw garlic cloves in the morning may keep your cardiovascular diseases miles away.

5) It may lower the risk of cancer

Garlic contains a large number of bioactive compounds (like allylsulfide derivatives) which have anticancer properties. It also contains selenium which is also known to anticancer actions mainly in control of genes involved in carcinogenesis. (5)

So if you want to lower the risk of cancer then start consuming at least one to two raw garlic everyday along with a healthy lifestyle.

6) It may prevent Thromboembolism

Formation of a clot in a blood vessel (called thrombosis) that breaks off as an embolus and is carried by blood stream to plug another blood vessel is known as thromboembolism. 

In a study it was found that consuming 10 grams of raw garlic daily after breakfast for two months can cause a significant decrease in serum cholesterol; and increase in fibrinolytic activity and clotting time. These results are indicative that garlic may be useful in prevention of thromboembolic phenomenon. (6)

7) It may relieve intestinal Ailments

Friends, garlic aids in normal functioning of liver and gall bladder. Eating raw garlic is very effective in stimulating digestion and appetite.

An upset stomach can obstruct your daily life. Helicobacter pylori is a common pathogenic bacteria in the stomach. Raw garlic has anti-bacterial effect on Helicobacter pylori (H. pylori) and may be prescribed along with other routine drugs for the treatment of its infection. (7)

Eating raw garlic is also very effective in treating stomach problems like diarrhea.

8) It may boost your immune system and can fight sickness, including the common cold

Garlic is known to boost the functioning of the immune system.

It contains phytonutrients which have antioxidant properties; and these phytonutrients reduce oxidative stress and flush out toxins from the body. Studies conducted on rats have found that garlic extract increased the different types of immune cells in their body. (8)

In one another 12 week period study on 146 volunteers, it was found that the group consuming garlic supplement daily had fewer number of colds than the placebo group. Also, the average duration of cold symptoms was also reduced from 5 days in the placebo group to 1.5 days in the garlic group. (9)

9) It may improve your bone health

Unhealthy lifestyle and increasing age can make your bones weak, which can cause fractures and osteoporosis. Garlic has been found to be protective against osteoporosis.

In a study it was found that diallyl sulfide, a compound present in garlic, helps to suppress matrix-degrading proteases (enzymes) and thus prevents the bones from damage. (10) 

10) It may help to detoxify Heavy Metals in the Body

Heavy metals can be dangerous for you and thus it is best to get rid of heavy metal (even in traces) from your body.

A study has proved that pickled garlic was very effective in lowering cadmium levels. (11)

In another four week study on 117 workers at a car battery industry found that garlic consumption had reduced lead levels in the blood and also reduced its signs of toxicity like headache, systolic blood pressure etc. (12)

11) It may lower the risk of Alzheimer’s disease and Dementia

Friends, free radicals cause oxidative damage which further contributes to aging process. Consuming high doses of garlic supplements may significantly increase antioxidant enzymes in the body and thus reduces oxidative stress in the human body.

Garlic’s effects on reducing blood pressure and cholesterol, as well as its antioxidant properties may lower the risk of Alzheimer’s disease and Dementia. (13)

A bioactive compound called S-allyl-cysteine (SAC) found in garlic protects neuronal cells from beta-amyloid and apoptosis. The anti-inflammatory and antioxidant properties of garlic also lower the risk of dementia and Alzheimer’s disease. (14)

12) It may improve your athletic performance

Garlic was used in ancient cultures to reduce fatigue and to improve work capacity of laborers. It was given to Olympic athletes in ancient Greece as one of the performance enhancing agents. (15)

A study has suggested that garlic can reduce the exercise-induced fatigue. (16)

13) It may help in weight loss

You should include garlic in your diet, if you want to lose weight. It is due to the reason that garlic increases thermogenesis, reduces LDL (bad) cholesterol, and inhibits the expression of adipogenic tissues. (17)

Consuming 3-4 garlic cloves daily may aid weight loss.

14) It may help in reducing Yeast infections

Yeast infections can be very disturbing and embarrassing. Garlic is used as a natural remedy for yeast infections.

Studies have found that the fresh garlic extract is very effective in candida infections treatment. (18)

Another study has shown that vaginal cream containing garlic was effective against candida vaginitis. (19)

15) It may relieve cold sores

Cold sores or Fever blisters are fluid filled tiny blisters on and around your lips; often grouped together in patches. These can spread from one person to another by close contact (like kissing). These are mostly caused by HSV-1 (herpes simplex virus type 1) and rarely by HSV-2 (herpes simplex virus type 2).

Garlic contains antioxidant, anti-inflammatory, and antiviral properties and therefore it may relieve cold sores.  

16) It may improve Zinc and Iron absorption

Zinc and Iron are very necessary for normal functioning of various biological processes in your body.

Garlic contains sulfur-containing amino acids that have a positive influence on the bioavailability of zinc and iron. (20)

Thus consuming one to two garlic cloves daily can improve zinc and iron absorption.

17) It may help you live longer

Garlic has beneficial effects on important risk factors like blood pressure, it protects vital organs and cell functions, and it fights infectious diseases; in this way garlic may help you live longer. 

18) It may kill oral pathogens

Garlic contains Allicin, which has antimicrobial properties. Allicin helps to kill oral pathogens associated with periodontitis and dental caries. (21)

In a study, it was found that mouthwash containing garlic extract was effective against the reduction of oral salivary micro-organisms. (22)

19)  It may ameliorate Fatty liver

Fatty liver is a condition when too much fat builds up in liver cells. Although having small amount of fat in your liver is normal, but too much of fat can cause a health problem.

A study conducted on rats has found that Sulfur containing S-allylmercaptocysteine (SAMC) in garlic protects the liver from chronic injury by enhancing autophagy and reducing apoptosis during nonalcoholic fatty liver disease (NAFLD). (23)

20) It may prevent UTIs (urinary tract infections)

Garlic contains powerful antibacterial compounds that are ideal for curing UTIs.

Fresh garlic has the potential to decrease the growth of E. coli bacteria that cause UTI.

A study has found that it can prevent the growth of pseudomonas aeruginosa. It is a pathogen that colonizes the urinary tract walls and is responsible for causing recurrent nosocomial catheter-associated UTIs. (24)

21) Garlic benefits for skin

Garlic is also very beneficial for skin. It has antioxidant, antibacterial, antiviral, antifungal, and anti-inflammatory properties.

A research study has found that topical application of its extract is very effective in wound healing, psoriasis, alopecia areata, cutaneous corn, fungal and viral infections of the skin. (25)

Its anti-inflammatory properties are believed to be helpful in reducing the inflammation of acne.

22) Garlic benefits for hair

Garlic is beneficial for your hair health and appearance.

Its anti-inflammatory properties are helpful in killing microbes that may cause damage to your scalp and inhibit hair growth. And thus it helps to keep your scalp healthy.

It is rich in vitamins (like vitamin C, vitamin B-6), and minerals (like selenium, manganese, etc.) which are believed to promote healthy hair.

In a study it was found that the use of garlic gel along with topical betamethasone valerate is effective in the treatment of alopecia areata. (26)

What Is The Dosage Of Garlic?

Garlic can be consumed in several forms, like fresh raw garlic, garlic oil, roasted garlic, and aged garlic extract.

All the beneficial components of garlic are easily available in fresh garlic, making raw fresh garlic and aged garlic supplements the two best forms for taking its full benefits.

Following doses of garlic have been suggested

Fresh raw Garlic

2 to 5 gram (or one to two cloves of fresh raw garlic)

Garlic (dried powder)

0.4 gram to 1.2 gram (standardized to 0.6 percent allicin yield) divided in two to three doses per day.

Garlic oil

2 to 5 drops or as per your requirement

Aged garlic extract (AGE)

2400 mg divided in two equal doses           

What Are The Side Effects Of Garlic?

Apart from above benefits it may have following side effects:

Bad odor

Garlic has a strong and pungent odor, so its consumption may give you bad odor or unpleasant breath

Gastric issues like vomiting, nausea, heartburn, or gastritis

Garlic in large quantities can irritate your stomach lining and may cause gastritis.

So consuming it in large quantities can also cause heartburn, and in some cases may also cause nausea and vomiting.

Lowers blood pressure

Garlic when consumed in excess can cause low blood pressure.

Aggravates vaginal infection

Garlic when consumed in normal quantity can prevent vaginal infection, but if it is consumed in larger quantities can aggravate the vaginal infection.

Triggers migraine

If you suffer from a migraine then you should avoid consuming garlic in large quantities, as it may trigger a migraine.   

May cause allergy

Though it is very uncommon it can cause allergic reactions in some people, like hives, swelling of face, lips, tongue, and throat, difficulty breathing, etc.

In bleeding disorder

Garlic, mainly its fresh form, may increase the risk of bleeding in people suffering from bleeding disorders.

May prolong bleeding time in Surgery

Garlic may prolong bleeding time and also interfere with blood pressure. So it is better to stop consuming its high doses at least seven to ten days before a scheduled surgery.

Garlic Consumption During Pregnancy

Eating garlic can be beneficial and is usually safe to use during pregnancy as long as it is consumed in moderate amount. But consuming it in large amounts during pregnancy may cause serious issues like blood thinning, low blood pressure etc.

So to be on safer side, consume 1 to 2 cloves of garlic per day to avoid any complication.

What Are The Other Drugs That Will Affect Garlic?

Garlic should be used only after medical advice if you are using any of these medications:

  • Birth control pills
  • Cyclosporin
  • Theophylline
  • Chlorzoxazone
  • Warfarin
  • Medicines used to prevent blood clots, like clopidogrel, urokinase etc.
  • NSAIDs (nonsteroidal anti-inflammatory drugs), like indomethacin, naproxen, ibuprofen, etc.

Final word

For centuries garlic is used in the daily diet because of its beneficial effects on health. It may lower your LDL cholesterol levels, blood sugar levels, risk of cardiovascular diseases, and may also prevent thromboembolism.

Many research studies has now confirmed it.



1) US National Library of Medicine, National Institutes of Health.

2) US National Library of Medicine, National Institutes of Health.

3) US National Library of Medicine.

4) US National Library of Medicine.

5) US National Library of Medicine, National Institutes of Health.

6) US National Library of Medicine.

7) US National Library of Medicine, National Institutes of Health.

8) US National Library of Medicine.

9) US National Library of Medicine.

10) US National Library of Medicine.

11) US National Library of Medicine.

12) US National Library of Medicine.

13) US National Library of Medicine.

14) US National Library of Medicine.

15) US National Library of Medicine.

16) US National Library of Medicine.

17) US National Library of Medicine.

18) US National Library of Medicine.

19) US National Library of Medicine.

20) US National Library of Medicine.

21) US National Library of Medicine.

22) US National Library of Medicine.

23) US National Library of Medicine.

24) US National Library of Medicine.

25) US National Library of Medicine.

26) US National Library of Medicine.



This article is intended for informational purposes only. Any information associated with this article should not be considered as a substitute for prescription suggested by local health care professionals.


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