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Garlic as an antibiotic

January 15, 2021
benefits of the garlic

As you well know, antibiotics are a group of drugs used to fight infections, particularly infections caused by bacteria. But did you know that some herbs, spices, and foods naturally exhibit antibiotic properties? One of the most recognized is garlic, whose health benefits have been, and continue to be, widely studied by science1.

Scientific evidence indicates that, in addition to its excellent antioxidant, anti-inflammatory, circulatory, immunoprotective and detoxifying properties, garlic also has a marked antibiotic effect .

Garlic as an antibiotic: why is this effect?

Although the exact mechanism by which garlic exerts its antibiotic power has not been confirmed, there are several theories and research that try to explain it. These are some of the most important findings :

  • One study found that compounds in garlic alter the ability of bacteria to adhere to each other and to surfaces (a phenomenon known as biofilm )2.
  • Numerous studies have reported that allicin, the main organosulfur compound in garlic, interferes with bacterial enzymes and their metabolism 3.
  • It has been observed that garlic can increase the number of white blood cells in the body, and therefore, strengthen our ability to destroy pathogenic cells 4.

So far, the most widely accepted explanation is related to the power of allicin . It should be mentioned that allicin is not the only compound with antibiotic activity in garlic, however, it is the one that seems to show the best results.

Allicin originates from the amino acid alliin, in a conversion facilitated by the enzyme allinase. Alliin and allinase are contained in separate compartments within the garlic clove. Once the garlic is crushed, both elements come together to generate allicin, a highly volatile compound responsible for the unmistakable smell of fresh garlic.

According to the researchers, allicin can interfere with certain molecules in cells and create a reaction capable of deactivating proteins in key microbial processes, such as RNA synthesis. As an antimicrobial, allicin has been found to be active against all types of pathogens and their associated toxins5.

As we show below, allicin inhibits many common types of bacteria ; these include:

  • Staphylococcus aureus (abscesses, localized infections, dermatitis, etc.)
  • Streptococcus pyrogenes (suppurative respiratory infections, rheumatic fever).
  • Streptococcus aglactiae (neumonía, meningitis neonatal)
  • Streptococcus pneumonia (neumonía, otitis, meningitis, peritonitis)
  • Neisseria gonorrhoeae (ETS gonorrhea)
  • Escherichia coli (diarrhea, urinary tract infections, neonatal meningitis, sepsis)
  • Salmonella typhi (typhoid fever)
  • Bordetella pertussis (tos ferina).
  • Brucella abortus (brucellosis)
  • Helicobacter pylori (gastritis, gastric ulcers)

It can even be effective against Mycobacterium dreamsship(the main cause of dreamsship) when used in combination therapies. It can also inactivate viruses such as influenza B, herpes simplex viruses 1 and 2, rhinovirus, and human cytomegalovirus, as well as inhibit the growth of a wide range of parasites . To make matters worse, allicin has antifungal activity and inhibits the formation of mycotoxins.6.

Interesting data

  • All members of the genus Allium, such as onion , leeks , chives, and garlic, contain alliin and allinase; however, garlic shows an abnormally high concentration of both compounds. For example, it has been observed that at least 10% of the total protein in garlic bulbs is allinase. It is believed that thanks to this, garlic can produce allicin in greater quantities , at a faster rate.
  • The only bacteria that appear to be resistant to allicin are those that produce mucoid layers or capsules, such as some strains of the bacterium Pseudomonas aeruginosa, responsible for infections in the urinary tract and respiratory system, dermatitis, soft tissue infections, bacteremia, infections of bones and joints, gastrointestinal infections and systemic infections7.
  • It is said that in 18th century France, gravediggers drank wine with crushed garlic as a measure of protection against the plague. It is also known that in WWI and WWII, soldiers used garlic to prevent gangrene in their wounds.
  • Due to the increasing attention that the use of antibiotics is receiving in agriculture and livestock, some farms have turned to garlic. Adding garlic to pig feed is reported to cause similar health and growth results compared to common antimicrobial agents. Perhaps this could be a cheap and safe alternative to using antibiotics, resulting in healthy and, of course, tastier livestock.

What are the advantages and benefits of the antibiotic effect of garlic?

1-. Broad antimicrobial spectrum

Many common antibiotics can only kill a narrow spectrum of microbes. In contrast, garlic is considered a broad spectrum antibiotic agent, since it affects a wide variety of bacteria and germs 8 . Different researchers have pointed out that humble garlic has a broader spectrum than any antimicrobial substance that we know of: it is antibacterial, antifungal, antiparasitic, antiviral and antiprotozoal.

It is noted that to achieve a reliable antibiotic effect, it is necessary to use fresh garlic. Its antibiotic activity is maintained regardless of whether we use it internally or externally, but garlic powders and other commercial products are not a good alternative to take into account.

2-. Resistant bacteria

One of the most alarming problems facing modern medical science is the resistance that numerous bacteria have developed. The frequent or indiscriminate use of antibiotics is what has generated the development of these resistant strains. Surprisingly, garlic does not seem to produce the same effect , and even better, it shows effectiveness against bacteria that no longer respond to conventional antibiotic treatment.9.


Garlic is effective against specific bacteria that are known to develop resistant strains, for example Staphylococci, Mycobacteria, Salmonella, and some Proteus species.

3-. Antiviral activity

One weakness of conventional antibiotics is that they are not effective against viral infections. For this reason, they are not used to fight the common cold or flu , or to treat serious viral infections such as viral meningitis, viral pneumonia, or herpes infections. Compounds in garlic have been shown to attack influenza viruses, herpes, smallpox, and even human cytomegalovirus, a common source of secondary infection in people with AIDS.

4-. Less side effects

Virtually all drug substances cause side effects in our body. In the specific case of antibiotics, they can often cause headaches, poor appetite, and severe digestive discomfort (diarrhea, nausea, vomiting), among others. For their part, natural remedies are not exempt from adverse effects and contraindications, but it is known that in general they are less powerful and that therefore, the consequences are usually milder . Garlic can cause side effects such as bad breath, skin irritation, and blood thinning; however, at appropriate doses, these effects are not significant.

How to use garlic to take advantage of its antibiotic properties?

Garlic can be used in many ways to take advantage of its natural antibiotic effect . In general, it can be ingested orally or used as a topical remedy on the skin.

Here we suggest some popular forms of consumption:

  • Raw garlic . It is not the preferred option of many, but it is one of the most effective. Peel and chew a raw garlic clove; This will allow the allicin to also be absorbed directly into the bloodstream through the tongue and the lining of the mouth. If the flavor is too strong and you don’t want to chew it, you can cut a garlic clove into smaller pieces and swallow them like a pill.
  • Garlic with honey . Combining garlic with honey is one of the most used variants to combat a sore throat, inflammation and cough. A home remedy par excellence is garlic, honey and lemon syrup.
  • Fresh garlic tea or garlic milk . Also widely used to alleviate flu and cold symptoms, as well as to relieve body aches and combat constipation. Garlic tea and milk can be made in 5 minutes; you don’t need more than one of the two liquids and minced garlic.
  • Garlic vinaigrette . Mix several tablespoons of vinegar, crushed fresh garlic, and olive oil to make a rich homemade dressing. Use it several times a day to drizzle your stir-fries and salads.
  • Olive oil infused with garlic . Similar to the previous suggestion, you can add minced garlic in a bowl of olive oil and let it infuse and then spread it on toast, or just drizzle it on your meals.

Always use fresh garlic, making sure to mince, crush or crush it and let it steep for 10 minutes before using. This is essential for the antibiotic compound allicin to form.

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Remember that allicin deactivates when exposed to heat. Its concentration is also reduced in commercial garlic powder and too old garlic cloves.

It may interest you: Healthy Properties of Black Garlic – What Makes It So Special?

What about garlic tablets?

Garlic tablets (capsules, lozenges) are not as effective as fresh garlic, but if you cannot tolerate the above consumption methods, it is worth a try.

To make garlic supplements “odorless”, aged garlic is often used in their manufacture. Some claim that this can make allicin less potent.

There are many types of garlic pills on the market. Before buying, be sure to read the label carefully and compare the amounts of the active ingredient . Those that contain freeze-dried, dried, or aged garlic extracts with standardized ingredients are usually the best. Also, look for enteric-coated supplements, as they guarantee better absorption of the compounds (they will not dissolve in the stomach, but in the intestine)10.

In case you want to use garlic as an antibiotic , but topically ( against bacterial and fungal infections, insect bites, etc. ), these are some suggestions to keep in mind:

  • Garlic water wash . Add three cloves of crushed garlic to 1 liter of water and let it rest for several hours. Then drop the garlic water on the affected area to allow the garlic compounds to penetrate.
  • Sitz bath . Garlic infused water also serves as a sitz bath to combat vaginal bacterial infections.
  • Garlic poultice . Crushing several cloves of garlic and wrapping them in a thin gauze, forming a kind of poultice, can be used to apply pure garlic on the infected skin.

For external applications, it is very important not to put the garlic directly on the skin , as this can cause irritation and burns. It’s always a good idea to mix it with other beneficial ingredients, such as coconut oil, aloe vera, and honey.

What is the recommended dose of garlic?

To date, there is no set dose for using garlic as an antibiotic . However, the researchers have given a series of recommendations that can serve as a guide.

It is important to note that the amounts of allicin can change depending on the variety of garlic and the growing methods. This makes it nearly impossible to quantify how much garlic a course of antibiotics could “match”. Still, there is some consensus that taking 2-4 cloves of garlic , or 600 – 1,200 mg of aged garlic extract, may be a suitable daily dose to take advantage of the antibiotic effect of garlic , as well as its other health benefits 11 12.

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Possible contraindications and side effects

Although garlic is an effective and natural antimicrobial, its misuse can cause adverse effects like any other antibiotic. Some of the main caveats to consider are:

  • The excessive consumption of raw garlic can cause gastrointestinal problems such as diarrhea, vomiting, nausea, irritation, excessive gas, heartburn.
  • Garlic has an anticoagulant effect , hence its use in combination with this type of medication is not recommended.
  • Like conventional antibiotics, consuming too much garlic can affect the number of “good” bacteria in the gut. 13 . Eating probiotic foods, such as plain yogurt, kombucha, miso, and fermented vegetables, is recommended to counteract this effect.

When used in moderation, garlic does support the health of our microbiome.

  • Applying garlic directly to the skin can cause irritation, burns, and allergic symptoms.
  • Avoid using garlic oil antibiotic drops to treat ear infections. Despite being a very popular remedy, it is not advisable to do this without a doctor’s approval, especially when the ear is infected.
  • Its consumption and application are contraindicated in sensitive people or with a known allergy to garlic .

Remember that while garlic exhibits antibacterial, antiviral, and antiparasitic properties, it should not be used as a substitute for any prescription medication. Infections, especially those caused by bacteria, can cause serious health problems and be life-threatening.

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Final thought

The raw garlic not only serves to bring this incredible flavor to meals, can also promote our health thanks to its antibiotic power . Whether we eat it or apply it externally, its compounds can inhibit the growth of a broad spectrum of bacteria. Scientific evidence suggests that this effect is due to its high concentration of allicin , the same volatile oil responsible for its strong smell and pungent taste.



My name is Louise Hammond, and I am the creator of this website, a place to find information about tubers, bulbs and medicinal roots. In I show the properties, benefits, characteristics, photos and images, ways of growing and how to make delicious meals from starchy vegetables.