Garlic Oil: Health Benefits And Side Effects

Reviewed By Registered Dietitian Dr. Geeta Dharmatti, M.Sc,Ph.D, Clinical Nutritionist and Registered Dietician
by Sindhu Koganti

Before the advent of modern medicine, our ancestors relied on nature’s wonders to stay healthy. One of the most popular traditional medicines is garlic.

Garlic (Allium satvium) is a relative of the onion family and one of the most commonly used foods and flavoring agents across the globe. Garlic is renowned for its remarkable ability to fight numerous diseases.

On a small scale, garlic oil is made by crushing and soaking garlic cloves in vegetable oil. For large scale preps, it is produced by steam distillation. Like its source, garlic oil also has high therapeutic value and may help hair growth, improve heart health, and treat certain skin ailments.

To know more about the health benefits of garlic oil and ways to use it, keep scrolling!

Garlic Oil: Origin And Importance

Garlic (Allium sativum L.) originated in Central Asia. Its plant has been used as a flavoring agent and traditional medicine since time immemorial. It is known not only for its flavor but also for its digestive properties (1).

Garlic is used as a diuretic, diaphoretic, expectorant, and stimulant. The plant has been used to treat tuberculosis, cough, and cold in ancient medicine. Extracts of garlic have shown broad-spectrum antibacterial and antifungal activity as well (1).

In this article, we’ll be focusing on garlic oil. The essential oils of garlic have high amounts of sulfur-containing compounds. The medicinal properties of garlic have been attributed to its abundance of sulfur-containing compounds (1).

Additionally, garlic oil is known for its antifungal, antibacterial, antiparasitic, antiviral, and insecticidal properties (1).

Check out the list of health benefits you can reap from this oil in the next section.

10 Benefits Of Garlic Oil For Health And Wellness

From clearing up a chronic ear infection to boosting your immunity, garlic oil offers many benefits. It may control hypertension and relieve toothache. Find out how and why below.

1. May Induce Hair Growth And Promote Strength

Alopecia or hair loss can occur due to multiple reasons. Genetic tendencies, environmental triggers, exposure to chemicals, medicines, oxidative stress, and prolonged illness are a few of them.

One trigger of alopecia that can be corrected is a nutritional deficiency (2).

Minerals like zinc, calcium, iron, copper, chromium, iodine, and magnesium are necessary for building hair fiber. Biotin, vitamin B (folic acid, pyridoxine, and pantothenic acid), vitamin A, and vitamin E maintain the scalp and root health (2).

Supplementing them in your diet is the easiest way to stimulate hair growth. Spinach, broccoli, and garlic pods are rich in these micronutrients. Thus, eating garlic or applying garlic oil can prevent hair loss (2), (3).

Aromatherapy with garlic oil is also a good option. It can improve blood circulation in your scalp. Due to its phytochemical composition, garlic oil exerts antibacterial activity as well. You can apply it directly to your scalp or crush a few garlic pods and mix them with yogurt to use as a mask (3).

2. Effective Remedy For Skin Diseases And Wounds

The oil and extracts of garlic have anti-inflammatory, antibacterial, fibrinolytic, and wound-healing properties that may make it a substitute for classic antibiotics and antiseptics (4).

Administering garlic oil to female rats reduced postoperative inflammation. The sulfur-containing compounds in garlic extracts accelerate the formation of new tissue and activate blood supply to open wounds (5).

Garlic extracts are also effective in healing a variety of skin conditions like atopic dermatitis, acne, psoriasis, fungal infections, scars, wrinkles, and other signs of aging (5).

3. May Promote Heart Health

Garlic oil has been found to reduce the risk of cardiovascular diseases. Its active component, diallyl disulfide, is responsible for its anti-atherosclerotic effects. It increases the fibrinolytic activity (prevents blood clots) in patients and healthy individuals (6).

Platelet aggregation is one of the first steps in the formation of blood clots. When these clots occur in your coronary or cerebral arteries, it can lead to myocardial infarction or ischemic stroke. A garlic-rich diet can prevent platelet aggregation or thrombosis (7).

Garlic oil also increases the elasticity of blood vessels and circulation. Hence, it may lower the risk of cardiovascular diseases (CVDs) (6), (8).

4. May Heal Fungal Infection And Diseases

Experimental studies have shown that garlic oil has excellent antifungal activity. It inhibits the growth of fungal species like Candida albicans and Penicillium funiculosum (9).

Garlic oil can penetrate the membranes of fungal organelles. Microscopic observations have revealed that garlic oil damages fungal mitochondria and vacuoles. It alters the expression of certain essential genes that are involved in basic regulatory functions and pathogenicity of fungi (9).

Garlic oil and other garlic formulations can be used to treat candidiasis. Other fungal diseases, like tinea pedis (foot infection), superficial mycoses (skin infection), and otomycosis (ear infection), can also be addressed with this oil or extract (9), (5), (10).

5. May Have Immunity-boosting And Anti-inflammatory Effects

Garlic oil and other derivatives of garlic exhibit anti-inflammatory and immunomodulatory effects. It can suppress the production of pro-inflammatory cellular messengers like nitric oxide (NO), prostaglandins, and interleukins. Its sulfur compounds act on the immune system cells that trigger the production of such molecules (11).

Arachidonic acid is a precursor of several anti-inflammatory compounds, like prostaglandins. Garlic oil has been proven to be a potent inhibitor of arachidonic acid. It may also inhibit the enzymes involved in the synthesis of prostaglandins and other eicosanoids (11).

Animal studies have proven the immunomodulatory effects of garlic oil. Treatment with this oil reportedly shifts the balance of Th1 and Th2 cells towards Th2 cells.

While Th1 cells are responsible for the production of inflammatory compounds, the Th2 cells trigger the immune response (humoral or body) to douse the inflammation. This step involves antibodies and designated cells and brings about the anti-inflammatory effect (11).

6. May Prevent Neurodegenerative Diseases And Improve Brain Health

Distilled garlic oil contains various sulfur compounds, like diallyl disulfide (DADS) and diallyl trisulfide (DAT). These organic compounds prevent the oxidation and accumulation of cholesterol (12).

Lipid peroxidation is one of the critical factors behind aging. Excess cholesterol/lipids can get oxidized and form amyloid plaques or clots in the brain, heart, and bloodstream (12).

Amyloid plaques can narrow blood vessels and cause blood clots, which may ultimately cause neuron degeneration. Rapid neuronal cell death leads to memory loss or dementia. In later stages, it can lead to Alzheimer’s disease (AD), vascular dementia, and atherosclerosis (12).

7. May Calm Toothaches And Mouth Sores

Garlic is commonly used as a spice because of its medicinal properties. Chewing garlic pods releases the essential oils and phytochemicals into the oral cavity. These active elements can heal mouth sores, oral ulcers, sore gums, and toothache (13).

Garlic has broad-spectrum antibacterial, antiviral, and antifungal properties. Directly applying a paste made from garlic bulb on the affected teeth can relieve gingivitis (13).
It can also prevent the formation of dental plaque by inhibiting oral bacteria (Streptococcus mutans, S. sanguis, S. Salivarius, Pseudomonas aeruginosa, and Lactobacillus spp.) (13).

8. May Eliminate Enteric (Gut) Pathogens

Garlic oil demonstrates wide-spectrum antimicrobial activity against gut (enteric) pathogens. It can also inhibit enteric bacteria that cause food poisoning (14).

The allicin and other organosulfur compounds found in this oil are identified as the active ingredients that show inhibitory effects against Helicobacter pylori – gut pathogens that cause gastric cancer and several gastrointestinal (GI) disorders (14).

However, the antimicrobial activity may be reduced in the acidic enteric environment. This is probably why this property of garlic oil is not well-researched or documented (14).

9. May Possess Antiviral Activity

Garlic extracts exhibit antiviral activity. Human cytomegalo virus (HCMV), Influenza B virus, Herpes simplex virus type 1, Herpes simplex virus type 2, Parainfluenza virus type 3, vaccinia virus, vesicular stomatitis virus, and Human rhinovirus type 2 are a few viruses that are sensitive to these extracts (15).

Experiments have also proven that allicin-containing supplements can prevent bouts of the common cold. Ajoene, allicin, and allitridin are a few antiviral compounds found in garlic extracts.

They enhance the activity of NK-cells (natural killer-cells). These immune system cells destroy virus-infected cells (15).

Garlic phytochemicals also inactivate critical viral genes and enhance the production of neutralizing antibodies in your blood (15).

10. May Have Insecticidal And Acaricidal Properties

Garlic oil has been identified as a potent repellant. It shows an anti-feeding effect against blood-sucking parasites (hematophagous arthropods). Volunteers experienced about 97% protection from female feeding sandflies (Phlebotomus papatasi) bites when they applied garlic oil topically on the skin (16).

In another experiment, Culex quinquefasciatus mosquito larvae that were exposed to 5 ppm (parts per million, a unit of concentration) of diallyl disulfide in garlic oil were killed (100% mortality). However, some studies show garlic oil to be ineffective against adult mosquitoes (17).

Garlic oil also reduces the fecundity (ability to reproduce) of mites. Two-spotted spider mites, beetles, weevils, and other such species have been found to be susceptible to garlic oil. A few studies have proposed garlic oil to be a better acaricide than rosemary oil, jojoba oil, or a soybean-sunflower oil mix (17).

Like other garlic extracts, garlic oil can also work as a herbicide, nematicide, molluscicide, and algicide.

Above all, garlic oil is affirmed Generally Recognized As Safe (GRAS) as a food ingredient, seasoning, or flavoring by the US FDA (18).

In short, you can use garlic oil for cooking. It can work as a skin conditioner, hair tonic, antiviral and antibacterial agent, and pesticide.

Did You Know?

The source of garlic odor is the result of the conversion of the phytochemical alliin to allicin.

This conversion is brought about by the enzyme allinase. This enzymatic conversion takes place only on cutting or crushing the garlic pods.

Due to the intermediate step of enzymatic conversion, biochemists tend not to regard garlic oil as an ‘essential’ oil.

You must have come across many side effects of garlic. Does garlic oil have side effects as well? Let’s find out!

Does Garlic Oil Have Side Effects?

Though a lot of research has been done on the side effects of garlic, not a lot has been written or studied about the disadvantages of using garlic oil.

We certainly cannot presume it is entirely safe for us either. This is because garlic oil contains phytochemicals like allicin that are harmful to your liver (hepatotoxic) in large doses (17).

Evidence shows acute human health effects caused by these bioactive ingredients. A few of the symptoms include:

  • Dermatitis
  • Halitosis
  • Asthma
  • Coagulation dysfunction
  • Cardiovascular disease or discomfort
  • Gastrointestinal dysfunction
  • Eczema
  • Irritation to open wounds

Consuming whole garlic pods may also trigger adverse effects.

However, garlic and garlic oil are categorized as non-toxic substances. They are non-toxic to humans and repellent targets like birds and insects.

Also, garlic and garlic oil are not identified as carcinogens by the International Agency for Research on Cancer (IARC). This indicates that we can all (well, most of us) use garlic oil.

How do we use it so that it doesn’t elicit an adverse reaction? Find out the recommended dosage of garlic oil and tips to use it in the next section.

How To Use Garlic Oil? How Much Of It Is Recommended?

There is no particular set or recommended dose for using garlic oil. The safest option would be to consult a healthcare professional.

Discuss why you wish to use this oil. Weigh out the benefits and risks. Follow the dosage set by them for the best results.

Pure garlic oil is a product of the steam distillation of garlic. Although edible, it is regarded as unpalatable and has a pungent odor.

If you wish to use garlic oil, you can get a bottle of it here. Garlic oil capsules are also a fuss-free and odor-free option. They are user-friendly and effective. Buy these softgels here.

You can also make garlic oil at home. However, it is going to be a crude prep. More importantly, you might end up with ‘garlic-infused’ oil and not proper garlic oil.

Here’s the recipe for garlic oil.

How To Make Garlic Oil At Home

  1. Crush four cloves of garlic directly in a heated saucepan.
  2. Pour in half a cup (120 ml) of olive oil.
  3. Squeeze the cloves of garlic through a garlic press or a ladle directly into the pan. (You don’t need to peel the garlic before putting it in the press. The peel will remain in the press while you squeeze it.)
  4. Stir the garlic and olive oil together, so the garlic is evenly distributed in the pan.
  5. Heat the mixture over medium-low heat for 3 to 5 minutes.
  6. Cook the mixture, stirring it occasionally until the garlic is light brown and slightly crispy.
  7. Don’t let the oil come to a boil. A light simmer is enough. (Avoid overcooking the garlic. If it turns very dark, you’ve cooked it too long, and the oil will be bitter.)
  8. Remove the pan from the heat and pour the mixture into a container.
  9. Let the mixture cool down completely.
  10. If you don’t want tiny bits of garlic in your oil, you can strain it through a colander or sieve as you pour the mixture into the container. Leaving the garlic pieces in the oil will create a stronger flavor as it continues to infuse over time.
  11. Transfer the contents to an airtight container and seal it tightly.
  12. Keep the oil in the refrigerator for up to 5 days.
  13. Shake the container now and then to mix up the flavors.

You can also prepare garlic oil without cooking/roasting. It will take a little longer, though. Here’s what you need to do:

  1. Crush 8-10 medium-sized garlic cloves with the back of your knife.
  2. Peel the crushed pods. Use your hands to minimize the loss of oils.
  3. Transfer the crushed pods to a 0.5 to 1-liter glass jar with an airtight lid.
  4. Add about two cups (450-500 ml) of olive oil. (You can replace olive oil with an oil of your choice. You can also add herbs like rosemary, thyme, and parsley along with the garlic cloves for added aroma.)
  5. Seal the jar tightly and store it in the refrigerator for 2-5 days. Your bottle of garlic-infused herb oil is ready!

Caution

  • Throw homemade garlic oil away after five days if you have not used it to be safe and avoid ingesting dangerous bacteria.
  • Freeze the garlic oil for up to one year if you want it to last longer.
  • Never store garlic oil at room temperature. It can cause botulism, a fatal form of food poisoning
  • Soak garlic and herbs in 3% citric acid at room temperature for 24 hours. This way, the acid fully penetrates the ingredients and creates an unsuitable environment for the growth of botulism bacteria

Keep reading for more tips on storing these oils.

How To Store Garlic-Infused Oil

All vegetable oils retain quality better at cold temperatures and away from light.

Oils infused with herbs like basil, garlic, oregano, and rosemary can be safely stored at room temperature. However, oil flavor is maintained for a longer time if you store it in a refrigerator or freezer.

It is also best to protect infused oils from light. Store them in dark or amber-colored bottles. Make sure the bottles are clean and food grade.

Conclusion

Garlic and its oil have exceptional therapeutic value. Diallyl disulfide, diallyl trisulfide, ajoene, alliin, allicin, methyl allyl trisulfide, allyl sulfide, citral, geraniol, linalool, α– and β-phellandrene are the predominant constituents of garlic oil. They are responsible for the long list of benefits that garlic oil offers.

Since it is considered to be non-toxic, garlic oil can be used for ingestion and topical application. It is also of great use in public health and agriculture. Consult your doctor and figure out ways to incorporate this versatile oil into your diet.

Expert’s Answers For Readers’ Questions

Is garlic oil good for your skin?

Yes, garlic oil is good for your skin. Garlic possesses antifungal, antibacterial, antiviral, and antiseptic properties to treat various skin ailments.

Can I leave garlic on my face overnight?

No, garlic may cause skin irritation and burns if left on for a long time.

Is garlic good for anti-aging?

Yes, garlic is good for anti-aging. Garlic has strong antioxidant properties that can rejuvenate the skin.

18 sources

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Sindhu Koganti

Sindhu Koganti is a Biotechnology graduate and has been in the writing field for over 4 years now. She specializes in writing on Health and Wellness. She has hands-on experience in writing articles and press releases on Life Sciences and Healthcare, Food and Beverages, and Chemicals and Materials. When she’s not writing, she loves watching movies and listening to music. She also enjoys traveling.
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