Da Suan
StarAllium sativum
Synonyms: Allium sativum var. controversum, Porrum ophioscorodon, Allium sativum var. subrotundum, Allium pekinense, Allium ophioscorodon, Allium sativum var. ophioscorodon, Allium sativum f. sagittatum, Allium sativum f. vulgare, Allium scorodoprasum var. multibulbillosum, Allium sativum subsp. ophioscorodon, Allium sativum var. pekinense, Allium scorodoprasum var. viviparum, Porrum sativum, Allium sativum subsp. controversum, Allium controversum, Allium sativum f. asiae-mediae, Allium sativum var. vulgare, Allium sativum subsp. subrotundum, Allium sativum subsp. asiae-mediae, Allium scorodoprasum subsp. viviparum, Allium longicuspis, Allium sativum f. pekinense
☯ TCM Properties
Kills parasites (hookworms, pinworms and other intestinal parasites); Disperses abscesses and reduces swellings; Resolves toxicity; Warms the Stomach, strengthens the Spleen, promotes movement of Qi, reduces Stagnation and resolves toxicity; Prevents influenza and treats shellfish poisoning
Traditional Chinese Uses
Da Suan (garlic) is a warm, pungent herb with a broad therapeutic range in Chinese medicine. It kills parasites and relieves toxicity, particularly for intestinal worm infestations and food poisoning. Its antimicrobial properties are applied for dysentery, pertussis, and certain infections. As a warming food-herb, it promotes circulation, disperses cold Qi accumulations, and is used externally for carbuncles, ringworm, and snake bites. Its dual role as food and medicine reflects the core TCM concept of dietary therapy.
Western Herbalism Properties
Gallery
Botanical Description
Allium sativum is a perennial herb cultivated as an annual, growing 30-60 cm tall. It produces a compound bulb (the head of garlic) consisting of 4-20 cloves enclosed in papery white or pinkish skin. Leaves are flat, linear, 1-2.5 cm wide, and bluish-green. The flowering scape is round and hollow, bearing an umbel of small whitish flowers mixed with bulbils, but most cultivated varieties rarely flower. The pungent odor is due to allicin and related sulfur compounds.
Cultivated worldwide in temperate and subtropical regions; originally native to Central Asia (Kazakhstan and surrounding regions). Prefers well-drained, fertile soils and full sun.
Allium sativum is a domesticated species with no known wild populations. It has been cultivated for over 5,000 years and is grown globally. No conservation concerns.
Active Constituents
Alliin (S-allyl-L-cysteine sulfoxide)
Organosulfur (cysteine sulfoxide)Concentration: Roughly 0.5-1% of fresh bulb; the main storage sulfur compound
Odourless precursor stored in intact cloves. When tissue is crushed it is converted by the enzyme alliinase into allicin, the source of garlic's characteristic activity.
Allicin (diallyl thiosulfinate)
Organosulfur (thiosulfinate)Concentration: Formed on crushing; up to ~0.4% of fresh weight, unstable
Principal bioactive thiosulfinate responsible for much of the antimicrobial, antioxidant and antiplatelet activity; it decomposes into ajoene and diallyl sulfides.
Diallyl disulfide and diallyl trisulfide
Organosulfur (allyl sulfides)Concentration: Major volatile oil components / degradation products of allicin
Contribute cardiovascular, chemopreventive and antimicrobial actions; modulate hydrogen-sulfide signalling and several detoxifying enzymes.
Ajoene
Organosulfur (vinyl disulfide)Concentration: Secondary product of allicin breakdown
A potent antiplatelet compound; also shows antifungal and antithrombotic activity.
S-allylcysteine (SAC)
Organosulfur (water-soluble)Concentration: Enriched in aged garlic extract; well absorbed and stable
A stable, bioavailable marker of aged garlic extract with antioxidant, lipid-modulating and blood-pressure-lowering activity.
gamma-Glutamyl-S-allylcysteines
Organosulfur (peptide)Concentration: Second main sulfur pool of the intact bulb
Precursors that are converted to S-allylcysteine on ageing; associated with blood-pressure and lipid effects.
Fructans (inulin-type polysaccharides)
Carbohydrate / prebiotic fibreConcentration: Up to ~65% of dry weight
Prebiotic fibres that support gut microbiota; contribute to metabolic effects.
⚠ Drug Interactions
Saquinavir and other protease inhibitors
In a controlled pharmacokinetic study garlic caplets reduced saquinavir AUC by about 51%, trough by 49% and Cmax by 54%, attributed to induction of intestinal CYP3A4 and P-glycoprotein.
Clinical note: Avoid high-dose garlic supplements with saquinavir and similar CYP3A4/P-gp-dependent antiretrovirals; monitor drug levels if unavoidable.
Warfarin and other anticoagulants
Garlic's antiplatelet organosulfur compounds (ajoene, allicin) can add to the anticoagulant effect; case reports describe raised INR and bleeding, though controlled trials with aged garlic did not show increased haemorrhage.
Clinical note: Monitor INR and for bruising or bleeding; caution with concentrated supplements, especially peri-operatively.
Antiplatelet drugs (aspirin, clopidogrel)
Ajoene and allicin inhibit platelet aggregation, which may add to the effect of antiplatelet agents and prolong bleeding time.
Clinical note: Use caution with concurrent antiplatelet therapy; discontinue high-dose supplements 7-10 days before surgery.
Antidiabetic drugs
Meta-analyses show garlic modestly lowers fasting glucose, which may add to the effect of hypoglycaemic medication.
Clinical note: Monitor blood glucose when combined with antidiabetic therapy.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3-9 g | daily | — | adult | Often used raw or as 1-3 crushed cloves; may irritate the stomach and mucosa in large amounts |
Preparation Methods
Fresh crushed cloves (internal)
Parts: bulb (cloves)
Crush or chop 1-3 raw cloves and let stand a few minutes to allow allicin to form, then swallow or add to food. Garlic is generally not decocted for long periods as heat destroys allicin.
External paste / application
Parts: bulb (cloves)
Mashed garlic applied topically (often diluted) to abscesses, fungal skin lesions or insect bites; prolonged direct contact can burn the skin, so applications are kept brief.
Aged garlic extract / supplement
Parts: bulb (cloves)
Standardised aged garlic extract capsules (commonly 600-1200 mg/day) are used in cardiovascular research for a milder, more stable and better-tolerated preparation.
Clinical Studies
Aged garlic extract reduces blood pressure in hypertensives: a dose-response trial
In treated but uncontrolled hypertensives, aged garlic extract (up to 4 capsules, ~960 mg, daily) lowered systolic blood pressure by about 10 mmHg versus placebo over 12 weeks, with a dose-response relationship and good tolerability.
The effect of garlic supplements on the pharmacokinetics of saquinavir
In ten healthy volunteers, twice-daily garlic caplets reduced the mean saquinavir AUC by 51%, demonstrating a clinically important herb-drug interaction with a CYP3A4/P-glycoprotein substrate.
The effect of aged garlic extract on blood pressure and other cardiovascular risk factors in uncontrolled hypertensives: the AGE at Heart trial
Aged garlic extract (1.2 g/day, providing 1.2 mg S-allylcysteine) lowered systolic blood pressure and favourably influenced arterial stiffness, gut microbial diversity and cholesterol in uncontrolled hypertensives over 12 weeks.
Historical Texts
Ming Yi Bie Lu (Miscellaneous Records of Famous Physicians)
Han-Wei period, attributed to Tao Hongjing (c. 5th-6th century)Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty (1578)References
- Borrelli F, Capasso R, Izzo AA. Garlic (Allium sativum L.): adverse effects and drug interactions in humans . Molecular Nutrition & Food Research (2007) [DOI]
- Ried K, Frank OR, Stocks NP. Aged garlic extract reduces blood pressure in hypertensives: a dose-response trial . European Journal of Clinical Nutrition (2013) [DOI]
- Piscitelli SC, Burstein AH, Welden N, Gallicano KD, Falloon J. The effect of garlic supplements on the pharmacokinetics of saquinavir . Clinical Infectious Diseases (2002) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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