Allicin: Uses, Benefits, Side Effects, Dosage, Precautions

Allicin is a compound that may help ease inflammation and block free radicals, unstable molecules that harm cells and tissues in your body. The compound is one of garlic's primary active components and gives it its distinct taste and scent.

The amino acid alliin is a chemical found in fresh garlic and is a precursor of allicin. An enzyme called alliinase is activated when the clove is chopped or crushed. This enzyme converts alliin into allicin. Vitamin C Powder

Allicin: Uses, Benefits, Side Effects, Dosage, Precautions

Here's what to know about allicin's possible health benefits, risks, and how to use it.

Dietary supplements are not regulated like drugs in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement tested by a trusted third party, such as USP, ConsumerLab, or NSF.

Keep in mind, however, that even if a supplement is third-party tested, it isn't necessarily safe for all or effective in general. Therefore, you must talk to your healthcare provider about any supplements you plan to take and check in about any potential interactions with other supplements or medications.

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.

Many studies have shown that the allicin in garlic may support health in various ways. Here's a look at some of the more compelling evidence.

A review of 39 randomized controlled trials (a study that randomly assigns participants to experimental and control groups) found that regular use of compounds in garlic lowered people's cholesterol levels by about 8%.

In general, adults in the study with slightly elevated cholesterol levels—above 200 milligrams per deciliter (mg/dL)—who took garlic for at least two months had lower:

A 2016 review of studies also supports these findings. The results of eight of nine reviews found a marked decrease in total cholesterol.

Research suggests that allicin may help lower blood pressure and keep it within a healthy range. 

In adults with high blood pressure who took garlic supplements, the mean systolic blood pressure (the top number in a blood pressure reading) was around 8 points lower than those who took a placebo (sugar pill). Their diastolic blood pressure (the bottom number) was about 5 points lower.

In 1990, the National Cancer Institute (NCI) praised garlic for its ability to guard against cancer. Since then, multiple preclinical studies have shown that allicin and other active garlic compounds may shield against some cancers and keep cancer cells from spreading.

Research has explored its role against cancers of the:

It's important to note that most of these studies were done on animal models or cells in a test tube. Robust human trials are needed to learn more about allicin's effects on cancer.

The NCI does not recommend taking garlic supplements to prevent cancer.

Garlic is a natural antibiotic whose use has been documented since the 1300s. Allicin is the compound responsible for garlic's ability to fight illness. It's considered broad-spectrum, meaning it's able to target the two main types of bacteria that cause disease.

Allicin also seems to enhance the effect of other antibiotics. Because of this, it may help combat antibiotic resistance, which happens when, over time, bacteria do not respond to medicines meant to kill them.

In addition to the potential health benefits listed above, some people use allicin to help muscle recovery after a workout.

Your healthcare provider may recommend you take allicin to help lower blood pressure, blood sugar, or cholesterol or for other conditions. Allicin has some side effects to be aware of, and these may be common or severe.

Allicin causes a garlic odor or breath in about 1 in 3 people who use it.

It may also cause digestive issues, especially in high doses, such as:

These side effects may be more common with raw garlic than with supplements. Taking allicin with food may help limit or prevent these problems.

Skin blisters and burns have been reported with raw garlic topical application (on the skin). High doses may cause liver damage.

It is not known whether it is safe to take the compound for:

Garlic may cause allergies and shouldn't be taken if you are allergic to plants in the lily family, including:

If you are due to have surgery or another procedure, your healthcare provider may recommend that you avoid garlic and products with its compounds for seven to 10 days beforehand. This is because garlic can increase the risk of bleeding.

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.

There is no standard dose for allicin. The dose can vary based on your health needs and the specific product. In general, it's best to follow the instructions on the label.

Standard doses used in blood pressure studies were 600 to 900 milligrams (mg) daily of garlic powder for up to 24 weeks; 600 mg of garlic powder contains approximately 7.8 mg of allicin.

Higher daily doses are often divided into multiple doses taken throughout the day. Breaking up doses may also help limit some of the digestive side effects.

Be sure to talk with your healthcare provider about the correct dose for you.

So far, studies show little evidence of toxicity from allicin. One report suggested that septicemia (a serious blood infection), bradycardia (slow heart rate), or loss of consciousness could occur if high doses of allicin are taken for long periods.

More research is needed to determine if allicin could be toxic to adults at high doses.

If you are concerned about these or any other potential side effects, always discuss the use of allicin with your healthcare provider.

Allicin and other garlic compounds help keep blood clots from forming. This may raise the risk of bleeding. Be sure to talk with your healthcare provider if you also take a blood thinner such as Jantoven (warfarin), or other herbal and OTC aids that can thin your blood, such as:

Avoid high doses (more than 4 grams of fresh garlic or 3 mg of allicin) if you take warfarin or other blood thinners.

Allicin also interacts with a class of medicines called protease inhibitors used in human immunodeficiency virus (HIV) treatment.

If you have blood pressure or blood sugar issues and take medicines to manage these, be sure to talk with your healthcare provider before you try allicin. Using allicin at the same time may cause your blood pressure or blood sugar to drop too low, though there is not much evidence that these interactions cause harm.

It is essential to carefully read a supplement's ingredient list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.

Always store allicin products as directed on the package—typically in a cool, dry place and away from children and pets.

Several supplements have similar activities as allicin. For example, some people take omega-3 fatty acids to lower cholesterol.

Other supplements that may help control blood pressure are:

Supplements that may lower blood sugar include:

Many other supplements have been studied to prevent cancer. Some examples are:

Popular supplements that may be taken to prevent or treat colds include:

Yes, cooked garlic has less allicin than raw garlic. But because allicin forms after chopping the garlic, you can boost the active amount by waiting at least 10 minutes before you use or cook it. Avoid exposing garlic to heat higher than 140 degrees also helps retain allicin. One way to do this is to add garlic during the final stages of cooking.

Some studies suggest garlic may help prevent or treat colds. But current research hasn't determined what the effective dose should be or even if it helps at all.

Placing garlic cloves inside the vagina does not cure a yeast infection. It's best not to put any object into your vagina other than a tampon or suppository prescribed by your healthcare provider.

There are different methods (food and supplements) through which to get allicin. Generally getting allicin through its food source (chopped garlic) may be considered to be most effective. 

Allicin is found in raw garlic, one of the most commonly used foods in cooking. And it's volatile (unstable and quickly changes into other chemicals).

A garlic clove has about 5 to 18 mg of allicin. Pure allicin only remains stable in freshly crushed or cut garlic for a short time. But letting garlic sit for 10 minutes after crushing or cutting it may help boost allicin levels. Try not to heat it above 140 degrees F; temperatures above this may degrade the amount of allicin.

Allicin is found in garlic powder supplements, which can be formulated as:

Enteric-coated products are designed to bypass the stomach and, in theory, yield a higher amount of allicin. This is because the enzyme that produces allicin, alliinase, is thought to be inactive in the stomach's acidic environment.

The FDA does not regulate supplements, so their quality and potency can vary. Amounts of allicin released in the body are often lower than the product labels claim.

Be sure the product has been certified by one or more of these agencies:

Allicin is one of the main active compounds derived from garlic. It may help prevent certain cancers and may help lower blood sugar, cholesterol, and blood pressure. It may help your muscles recover after a workout and protect against infections.

Allicin supplements have few risks. It might cause some stomach upset and increase the risk of bleeding. Its safety isn't known for children or pregnant or breastfeeding women.

If you're interested in allicin supplements, talk with your healthcare provider or pharmacist about whether they're safe and beneficial.

Ried K. Garlic lowers blood pressure in hypertensive individuals, regulates serum cholesterol, and stimulates immunity: an updated meta-analysis and review. J Nutr. 2016;146(2):389S-396S. doi:10.3945/jn.114.202192

Borlinghaus J, Albrecht F, Gruhlke MC, Nwachukwu ID, Slusarenko AJ. Allicin: chemistry and biological properties. Molecules. 2014;19(8):12591-12618. Published 2014 Aug 19. doi:10.3390/molecules190812591

De Greef D, Barton EM, Sandberg EN, et al. Anticancer potential of garlic and its bioactive constituents: a systematic and comprehensive review. Semin Cancer Biol. 2021;73:219-264. doi:10.1016/j.semcancer.2020.11.020

Ribeiro M, Alvarenga L, Cardozo LFMF, et al. From the distinctive smell to therapeutic effects: Garlic for cardiovascular, hepatic, gut, diabetes and chronic kidney disease. Clinical Nutrition. 2021;40(7):4807-4819. doi:10.1016/j.clnu.2021.03.005

National Center for Complementary and Integrative Health (NCCIH). Garlic.

Ried K, Toben C, Fakler P. Effect of garlic on serum lipids: an updated meta-analysis. Nutr Rev. 2013;71(5):282-99. doi: 10.1111/nure.12012.

Schwingshackl L, Missbach B, Hoffmann G. An umbrella review of garlic intake and risk of cardiovascular disease. Phytomedicine. 2016;23(11):1127-1133. doi:10.1016/j.phymed.2015.10.015

Ried K. Garlic lowers blood pressure in hypertensive subjects, improves arterial stiffness and gut microbiota: A review and meta-analysis. Exp Ther Med. 2020;19(2):1472-1478. doi:10.3892/etm.2019.8374

Bayan L, Koulivand PH, Gorji A. Garlic: a review of potential therapeutic effects. Avicenna J Phytomed. 2014;4(1):1-14.

Mondal A, Banerjee S, Bose S, et al. Garlic constituents for cancer prevention and therapy: from phytochemistry to novel formulations. Pharmacol Res. 2021;105837. doi:10.1016/j.phrs.2021.105837

Haghi A, Azimi H, Rahimi R. A Comprehensive Review on Pharmacotherapeutics of Three Phytochemicals, Curcumin, Quercetin, and Allicin, in the Treatment of Gastric Cancer. J Gastrointest Cancer. 2017;48(4):314-320. doi:10.1007/s12029-017-9997-7

Use of Natural Products by Children : What the Science Says. NCCIH.

Choo S, Chin VK, Wong EH, et al. Review: antimicrobial properties of allicin used alone or in combination with other medications. Folia Microbiol (Praha). 2020;65(3):451-465. doi:10.1007/s12223-020-00786-5

Doma K, Devantier-Thomas B, Gahreman D, Connor J. Selected root plant supplementation reduces indices of exercise-induced muscle damage: s systematic review and meta-analysis. Int J Vitam Nutr Res. 2020;1-21. doi:10.1024/0300-9831/a000689

El-Saber Batiha G, Magdy Beshbishy A, G Wasef L, et al. Chemical Constituents and Pharmacological Activities of Garlic (Allium sativum L.): A Review. Nutrients. 2020;12(3):872. Published 2020 Mar 24. doi:10.3390/nu12030872

Majewski M. Allium sativum: facts and myths regarding human health. Rocz Panstw Zakl Hig. 2014;65(1):1-8.

Alare K, Alare T. Open Acc J of Toxicol Review of Toxicity of Allicin From Garlic. Open Acc J of Toxicol. 2020;4(5). doi:10.19080/OAJT.2020.04.555647

Ried K, Fakler P. Potential of garlic (Allium sativum) in lowering high blood pressure: mechanisms of action and clinical relevance. Integr Blood Press Control. 2014;7:71-82. Published 2014 Dec 9. doi:10.2147/IBPC.S51434

Ajebli M, Eddouks M. Phytotherapy of Hypertension: An Updated Overview. Endocr Metab Immune Disord Drug Targets. 2020;20(6):812-839. doi:10.2174/1871530320666191227104648

Borghi C, Cicero AF. Nutraceuticals with a clinically detectable blood pressure-lowering effect: a review of available randomized clinical trials and their meta-analyses. Br J Clin Pharmacol. 2017;83(1):163-171. doi:10.1111/bcp.12902

Shanmugam KR, Shanmugam B, Subbaiah GV, Ravi S, Reddy KS. Medicinal Plants and Bioactive Compounds for Diabetes Management: Important Advances in Drug Discovery. Curr Pharm Des. 2021;27(6):763-774. doi:10.2174/1381612826666200928160357

Khuda-Bukhsh AR, Das S, Saha SK. Molecular approaches toward targeted cancer prevention with some food plants and their products: inflammatory and other signal pathways. Nutr Cancer. 2014;66(2):194-205. doi:10.1080/01635581.2014.864420

Lawson L, Hunsaker S. Allicin bioavailability and bioequivalence from garlic supplements and garlic foods. Nutrients. 2018;10(7):812.

Song K, Milner JA. The influence of heating on the anticancer properties of garlic. J Nutr. 2001;131(3s):1054S-7S. doi:10.1093/jn/131.3.1054S

Percival SS. Aged garlic extract modifies human immunity. J Nutr. 2016;146(2):433S-436S. doi:10.3945/jn.115.210427

Lissiman E, Bhasale AL, Cohen M. Garlic for the common cold. Cochrane Database Syst Rev. 2014;2014(11):CD006206. doi:10.1002/14651858.CD006206.pub4

Catanzaro E, Canistro D, Pellicioni V, Vivarelli F, Fimognari C. Anticancer potential of allicin: A review.Pharmacol Res. 2022;177:106118.doi:10.1016/j.phrs.2022.106118

Office of Dietary Supplements. Botanical Dietary Supplements - Background Information.

Ashraf R, Khan RA, Ashraf I, Qureshi AA. Effects of Allium sativum (garlic) on systolic and diastolic blood pressure in patients with essential hypertension. Pak J Pharm Sci. 2013;26(5):859-63.

Chan JY, Yuen AC, Chan RY, Chan SW. A review of the cardiovascular benefits and antioxidant properties of allicin. Phytother Res. 2013;27(5):637-46. doi: 10.1002/ptr.4796

National Center for Biotechnology Information. Allicin.

National Center for Complementary and Integrative Health. Garlic.

Oregon State University: Linus Pauling Institute. Garlic.

By Megan Nunn, PharmD Megan Nunn, PharmD, is a community pharmacist in Tennessee with over twelve years of experience in medication counseling and immunization.

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Allicin: Uses, Benefits, Side Effects, Dosage, Precautions

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