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Allium sativum

Allium sativum                  

Common Name: Garlic

 Family: Liliaceae

Part used:  Bulb


  • Volatile oil (sulfur containing compounds): sulfoxides (ajoene, alliin, allicin) & thiocyanates
  • Enzymes (allinase)
  • Nutrients: Carbohydrates, lipids & amino acids
  • Lectins (lectin-allinase complexes)

Medical actions:


  • Anti-microbial
  • Antispasmodic & Carminative
  • Anti-thrombotic (Anti-platelet aggregant)
  • Cardioprotective
  • Diaphoretic
  • Expectorant
  • Hepatoprotective
  • Hypoglycemic
  • Hypolipidemic
  • Hypotensive
  • Rubefacient








Medical uses: 

  • Historical use is recorded by many physicians and herbalists of the ancient world. Was recommended as an antiseptic, an antidote for poisonous bites, as a cough suppressant, and to expel intestinal parasites. Considered a good carminative for digestive problems and an excellent treatment for diarrhea, especially when due to infectious causes,  bacterial, fungal and viral infections.


  • VO & sulfur containing compounds (alliin & allicin) are largely responsible for effects.
  • Alliin is converted by allinase to alliicin when chopped, crushed and exposed to air (oxidized).
  • Allicin inhibits platelet aggregation, reduces cholesterol, and is antimicrobial and antioxidant.
  • Anti-thrombotic activity may be in part due to inhibition of thromboxane B2 synthesis, and anti-platelet activity is associated with allicin, ajoene, and sulfides.
  • Hepatoprotective possibly due to s-allyl components and prevention of glutathione depletion.


  • Fresh bulb: 1 clove eaten daily for prophylaxis. During acute infections, 1 clove TID. Note: Allow bulb to oxidize 1-3 min before ingesting for best effect.
  • Dried bulb: 2-4 g BID or 12:1 extract, 300 mg (standardized to 12 mg allicin), BID.
  • As food: Juice, syrup etc.
  • Topical: poultice, ear/nasal drops.


  • Can cause irritation to the gastric mucosa (especially fresh bulb). Avoid in acute stomach inflammation, acid reflux or irritation of mucosal surfaces.
  • High doses can cause breath & body odour.


  • Do not use within 10 days of surgery or with medications that inhibit blood coagulation.
  • Avoid excessive use in early pregnancy due to potential emmenagogue effects, and hypothyroidism as may cause reduced iodine uptake by the thyroid (theoretical).
  • Hypersensitivity (eg. allergy) has been known to occur.


  • May potentiate insulin (inhibits its breakdown) and hypoglycemic drugs.
  • May potentiate anticoagulants and increase bleeding time (eg. Aspirin, clopidogrel, warfarin) due to antiplatelet activity (theoretical). Monitor at doses equivalent to ≥ 3 g/day fresh garlic (low level of risk).
  • May enhance effects of cholesterol-lowering agents (theoretical).
  • May decrease drug level of HIV protease inhibitors.


  • Find a complete list of references for this monograph as well as images and a review of its evidence based applications in Dr. Marciano’s Herbal Textbook.



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