Herb Bulb (鳞茎 lín jīng)

Da Suan

Garlic · 大蒜

Allium sativum L. · Bulbus Allii Sativi

Also known as: Hu Suan (胡蒜)

Da Suan (Garlic) plant

Images shown are for educational purposes only

Garlic is one of the most widely recognized medicinal foods in the world. In Chinese medicine, it is valued for its powerful ability to fight infections, expel intestinal parasites, and stop dysentery. Its warm, pungent nature also helps settle a cold, weak stomach and can be applied externally to treat boils, abscesses, and fungal skin conditions.

Category Antiparasitic herbs
Therapeutic focus Digestive health Immune support Skin health Infection prevention

TCM Properties

Temperature

Warm

Taste

Acrid / Pungent (辛 xīn)

Channels entered

Spleen, Stomach, Lungs, Large Intestine

Parts used

Bulb (鳞茎 lín jīng)

Educational content • Consult qualified TCM practitioners for diagnosis and treatment

What This Herb Does

Every herb has a specific set of actions — here's what Da Suan does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Da Suan is primarily used to support these areas of health:

Digestive health Immune support Skin health Infection prevention

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Da Suan performs to restore balance in the body:

Resolves toxicity and reduces swelling Kills parasites Stops dysentery and diarrhea Warms the middle burner and dispels cold Disperses swelling of abscesses and sores

How these actions work

Resolves toxicity and reduces swelling (解毒消肿)

'Resolving toxicity' means Dà Suàn has a powerful ability to counteract and neutralize harmful pathogens, whether bacterial, fungal, or parasitic. In practical terms, this is why garlic has been used for centuries to treat infected wounds, boils, abscesses, and food poisoning. The 'reducing swelling' aspect refers to its ability to help inflamed, swollen tissue return to normal, particularly when applied directly as a poultice to early-stage skin infections.

Kills parasites (杀虫)

'Killing parasites' is straightforward: Dà Suàn has a direct toxic effect on intestinal worms, including hookworms and pinworms. For pinworm infections, mashed garlic mixed with a small amount of oil can be applied around the anus at bedtime. For hookworm prevention, garlic paste was traditionally applied to the skin of the hands and feet before fieldwork. However, for serious parasitic infections, garlic is typically used alongside stronger antiparasitic herbs rather than as a standalone treatment.

Stops dysentery and diarrhea (止痢)

'Stopping dysentery' refers to Dà Suàn's remarkable effectiveness against bacterial dysentery, both when taken orally and when used as a retention enema. Clinical observations in China have shown cure rates above 95% for bacterial dysentery using garlic preparations. This action combines its antimicrobial properties with its ability to warm and stabilize the intestines.

Warms the middle burner and dispels cold (暖脾胃、去寒湿)

As a warm, pungent substance entering the Spleen and Stomach, Dà Suàn can warm the digestive system when it has been invaded by cold. This is why garlic has been traditionally eaten during cold weather and with cold or raw foods. People with cold-type stomach pain that improves with warmth, poor appetite, or watery diarrhea may benefit from moderate garlic consumption. The Ben Cao Gang Mu describes garlic as able to 'go through the five organs, reaching all the orifices, expelling cold-dampness.'

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Da Suan is used to help correct these specific patterns.

Why Da Suan addresses this pattern

Dà Suàn's warm, pungent nature allows it to penetrate the Stomach and Large Intestine channels, where it powerfully clears toxic accumulation and stops dysentery. While Damp-Heat patterns typically call for cold herbs, Dà Suàn's unique strength lies in its potent toxin-resolving (解毒) action, which directly combats the pathogenic factors causing intestinal inflammation. Its warming quality also prevents the Spleen's transport function from being further impaired by excessive cold-natured treatment, making it especially useful when combined with cold, bitter herbs like Huáng Lián.

A practitioner would look for one or more of these signs

Diarrhea

Dysentery with mucus and blood in stool

Abdominal Pain

Cramping abdominal pain with tenesmus

Nausea

Nausea or vomiting with foul-smelling stool

Commonly Used For

These are conditions where Da Suan is frequently used — but only when they arise from the specific patterns it addresses, not in all cases

Arises from: Damp-Heat in the Large Intestine Cold Stagnation in the Stomach

TCM Interpretation

TCM understands dysentery and infectious diarrhea primarily as Damp-Heat or toxic Dampness invading the Large Intestine. The pathogenic factors disrupt the Spleen and Stomach's ability to transform and transport food and fluids, leading to undigested or bloody stool, cramping, and tenesmus. In cold-type diarrhea, the Spleen Yang is insufficient to transform fluids, leading to watery stool. Both patterns involve a fundamental disruption of the middle burner's digestive function.

Why Da Suan Helps

Dà Suàn directly enters the Stomach and Large Intestine channels, where it exerts its powerful toxin-resolving (解毒) and dysentery-stopping (止痢) actions. Its broad-spectrum antimicrobial properties, recognized in both classical texts and modern research, address the underlying infectious cause. For Damp-Heat dysentery, it is often paired with Huáng Lián to combine its warming dispersal with cold bitter drainage. For cold-type diarrhea, its warm pungent nature directly warms the Spleen and Stomach to restore normal digestive function.

Also commonly used for

Abdominal Pain

Cold-type epigastric and abdominal pain

Scabies

Scabies and fungal skin infections including tinea

Whooping Cough

Whooping cough (pertussis) in children

Intestinal Parasites

Hookworm and pinworm infections

Poor Appetite

Reduced appetite from cold in the digestive system

High Blood Pressure

Mild to moderate hypertension as adjunctive support

High Cholesterol

Elevated cholesterol and cardiovascular risk reduction

Herb Properties

Every herb has an inherent temperature, taste, and affinity for specific channels — these properties determine how it interacts with the body

Temperature

Warm

Taste

Acrid / Pungent (辛 xīn)

Channels Entered

Spleen Stomach Lungs Large Intestine

Parts Used

Bulb (鳞茎 lín jīng)

Dosage & Preparation

These are general dosage guidelines for Da Suan — always follow your practitioner's recommendation, as dosages vary based on the formula and your individual condition

Standard dosage

5–15g

Maximum dosage

Up to 30g in decoction; raw consumption should not exceed approximately 12.5g per day (about 2–3 cloves) to avoid gastric irritation and potential liver stress

Dosage notes

Use lower doses (5–10g) when taken raw or in fresh preparations, as the active allicin content is highest and most irritating to the stomach. Higher doses (10–15g or more) are appropriate when garlic is cooked, roasted (煨), or used in decoction, as heat reduces the pungent irritation. For anti-dysentery purposes, historical clinical protocols used 10% garlic infusions for retention enemas (100 mL at a time). Garlic should not be decocted for extended periods, as allicin is heat-labile and its volatile oils dissipate quickly with prolonged cooking. For external application, fresh garlic should be used, but contact time with skin should be limited to avoid burns (typically no more than 1–2 hours with a protective cloth layer).

Preparation

Da Suan is most often used fresh (raw or lightly cooked) rather than in prolonged decoctions, because its key active compound allicin is unstable and breaks down rapidly with heat. If used in decoction, it should be added near the end of cooking (后下, hou xia) to preserve its volatile oils. It can also be crushed into paste for pills, roasted in its skin (煨, wei) for milder effect, or used as fresh juice for topical application.

Processing Methods

In TCM, the same herb can be prepared in different ways to change its effects — here's how processing alters what Da Suan does

Processing method

Whole unpeeled garlic cloves are wrapped in wet paper or clay and roasted in hot ashes or a low oven until the flesh is soft and the pungency is significantly reduced.

How it changes properties

Roasting reduces the acrid pungency and the volatile allicin content, making garlic less stimulating to the stomach. The thermal nature becomes more moderately warm rather than hot, and the action shifts from strongly dispersing to more gently warming the middle Jiao. The Spleen- and Stomach-warming function is enhanced while the risk of gastric irritation is greatly reduced.

When to use this form

Preferred when garlic is used to warm the Spleen and Stomach for conditions like cold abdominal pain, poor appetite, or diarrhea in patients with a sensitive or weakened digestive system who cannot tolerate raw garlic.

Common Herb Pairs

These ingredients are traditionally combined with Da Suan for enhanced therapeutic effect

Huang Lian
Huang Lian 1:1 (equal parts, formed into pills)

Dà Suàn's warm, pungent, toxin-resolving action combined with Huáng Lián's cold, bitter, Damp-Heat clearing action creates a powerful synergy for treating dysentery. Dà Suàn prevents Huáng Lián's bitter cold nature from damaging the Stomach, while Huáng Lián provides the Heat-clearing strength that warm Dà Suàn alone cannot deliver. Together they clear toxins and stop bloody dysentery far more effectively than either herb alone.

When to use: Damp-Heat dysentery with bloody or mucus-laden stool, abdominal cramping, and tenesmus. This is the classical pair of the Suàn Lián Wán formula.

Bai Ji
Bai Ji Da Suan 30g (cooked into porridge) : Bai Ji powder 3g

Dà Suàn provides broad-spectrum antimicrobial action against the tubercle bacillus, while Bái Jí astringes the Lung and stops bleeding. The combination addresses both the infectious cause and the hemorrhagic complication of pulmonary tuberculosis.

When to use: Pulmonary tuberculosis (Lung consumption) with coughing of blood. A classical folk remedy combines garlic porridge with Bái Jí powder.

Mang Xiao
Mang Xiao Da Suan 120g : Mang Xiao 30-60g (mashed together into a paste for external use)

Applied externally as a combined poultice, Dà Suàn's warming, toxin-resolving action works with Máng Xiāo's cold, softening, and swelling-reducing properties to powerfully draw out inflammation and resolve abscesses. The temperature contrast between the two substances enhances penetration into inflamed tissue.

When to use: Acute appendicitis treated conservatively with external application, as well as soft tissue abscesses and localized infections. Applied as a topical compress over the affected area.

Comparable Ingredients

These ingredients have overlapping uses — here's how to tell them apart

Cong Bai
Da Suan vs Cong Bai

Both are pungent, warm allium-family bulbs that warm the interior and disperse cold. However, Cōng Bái (scallion white) is primarily an exterior-releasing herb that induces sweating and unblocks Yang Qi, while Dà Suàn's strength lies in resolving toxicity, killing parasites, and stopping dysentery. Choose Cōng Bái for early-stage Wind-Cold invasion requiring diaphoresis; choose Dà Suàn for intestinal infections, parasites, and toxic sores.

She Chuang Zi
Da Suan vs She Chuang Zi

Both herbs kill parasites and treat skin conditions like scabies and fungal infections. However, Shé Chuáng Zǐ is primarily used externally for genital itching, eczema, and dampness-related skin conditions, and also warms the Kidneys to strengthen reproductive function. Dà Suàn has a broader antimicrobial range covering intestinal parasites and dysentery as well as skin infections, but lacks Shé Chuáng Zǐ's Kidney-warming reproductive benefits.

Identity & Adulterants

Related species and common adulterations to be aware of when sourcing Da Suan

Da Suan (大蒜, Allium sativum) is sometimes confused with Xiao Suan (小蒜, Allium macrostemon), the native Chinese small garlic. The two are easy to distinguish: Da Suan has large bulbs with multiple large cloves and a sweeter-spicy taste, while Xiao Suan has very small bulbs with few tiny cloves and a sharper, more purely pungent taste. Medicinally, Xiao Suan (which is the source of Xie Bai / 薤白) has different properties and indications focused on opening the chest and treating chest impediment (胸痹), and should not be substituted for Da Suan. In the supplement industry, garlic products vary enormously in their allicin content depending on processing method, with some products containing little to no active allicin despite being labeled as garlic supplements. Authentic medicinal garlic should have a strong characteristic odor when crushed.

Educational content — always consult a qualified healthcare provider or TCM practitioner before using any herb.

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Da Suan

Slightly toxic

The main bioactive and potentially irritating compound in garlic is allicin (大蒜素, da suan su), formed when the precursor alliin is converted by the enzyme alliinase upon crushing or cutting the cloves. Allicin is a potent antimicrobial but also a strong mucosal irritant. At standard dietary or medicinal doses (a few cloves per day or 5-15g in decoction), garlic is safe. However, excessive raw consumption can cause gastric mucosal irritation, nausea, vomiting, and abdominal pain. Animal studies suggest that daily raw garlic intake exceeding roughly 0.5g per kilogram body weight may cause liver enzyme elevation and hepatic damage. A commonly cited safe limit for raw garlic consumption in an adult is approximately 12.5g per day (about 2-3 cloves). High-concentration garlic juice can cause hemolysis of red blood cells and, with prolonged excessive intake, may contribute to anemia. Topical application of raw garlic can cause chemical burns and blistering.

Contraindications

Situations where Da Suan should not be used or requires extra caution

Caution

Yin deficiency with Heat (阴虚火旺): People with signs such as facial flushing, afternoon low-grade fever, dry mouth, constipation, and irritability should avoid Da Suan. As the Ben Cao Cong Xin states, it is acrid-hot and can generate Phlegm and stoke Fire, depleting Qi and consuming Blood.

Avoid

Active gastric or duodenal ulcer: Da Suan's strongly acrid, irritating nature can directly damage the gastric mucosa, worsen ulceration, and cause gastric pain, nausea, and vomiting.

Caution

Eye diseases: Classical texts consistently warn that prolonged or excessive garlic consumption injures the Liver and damages the eyes. As the Ben Cao Gang Mu notes, 'eating it injures the Liver and damages the eyes.' Those with inflammatory or degenerative eye conditions should avoid it.

Caution

Non-bacterial diarrhea or intestinal inflammation: In cases where diarrhea is caused by factors other than bacterial infection, the strong irritant properties of raw garlic can aggravate intestinal mucosal congestion and edema, worsening the condition.

Caution

Pre-surgical period: Due to garlic's antiplatelet and mild anticoagulant properties, it should be discontinued at least 7 days before any planned surgical procedure to reduce the risk of excessive bleeding.

Caution

Topical application to skin under occlusive dressings: Fresh raw garlic applied directly to the skin, especially under bandages, can cause chemical burns, blistering, and contact dermatitis.

Avoid

Known allergy to garlic or Allium species: Allergic reactions ranging from contact dermatitis to anaphylaxis have been reported. Those with known sensitivity must avoid Da Suan entirely.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Garlic at normal culinary doses is generally considered safe during pregnancy. However, concentrated garlic supplements or medicinal doses should be used with caution. Classical Chinese sources note that garlic enema therapy is contraindicated during pregnancy. The herb's blood-moving and antiplatelet properties raise a theoretical concern about increased bleeding risk, particularly near delivery. Pregnant women should avoid large medicinal doses and consult a healthcare provider before taking garlic supplements.

Breastfeeding

Research has shown that garlic consumption by nursing mothers alters the odor and possibly the taste of breast milk, which can change infant feeding behavior. Some studies observed that infants spent more time attached to the breast when the mother had consumed garlic, while others showed initial reluctance. Garlic at normal dietary amounts is generally not considered harmful during breastfeeding, but nursing mothers should be aware that the volatile sulfur compounds do transfer into breast milk and may affect the infant's feeding pattern or cause fussiness.

Children

Garlic can be used in children at reduced doses appropriate to age and body weight. Classical pediatric formulas typically use small amounts (e.g. 1.5–5g). For garlic syrup preparations used to treat pediatric dysentery, dosages in classical clinical reports were: children aged 2–3 years, 2.5 mL of 20% garlic syrup per dose; under 10 years, 5 mL; over 10 years, 10 mL, given 3 times daily. Raw garlic is more irritating to the immature digestive tract of young children, so cooked or prepared forms (such as garlic syrup or honey-roasted garlic) are preferred. Topical garlic application on children's skin should be done with extra caution and for shorter durations, as their skin is more delicate and susceptible to chemical burns.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Da Suan

Anticoagulants and antiplatelet drugs: Garlic contains organosulfur compounds (particularly ajoene and allicin) that inhibit platelet aggregation. This may enhance the anticoagulant effect of warfarin, heparin, and similar medications, theoretically increasing bleeding risk. While one clinical trial of aged garlic extract found no significant hemorrhagic events in closely monitored patients on warfarin, caution is still advised, and patients should inform their prescribing physician if taking garlic medicinally.

HIV protease inhibitors: Garlic supplements have been reported to reduce serum levels of saquinavir (and potentially other protease inhibitors), likely through induction of CYP3A4 or P-glycoprotein activity. This could reduce antiviral efficacy and is a clinically significant concern.

Hypoglycemic medications: Garlic may lower blood glucose levels, which could potentiate the effect of insulin or oral hypoglycemic agents, increasing the risk of hypoglycemia. Blood sugar should be monitored when garlic is used medicinally alongside diabetes medications.

Antihypertensive drugs: Because garlic itself has mild blood-pressure-lowering effects, concurrent use with antihypertensive medications could lead to additive effects and hypotension.

NSAIDs: Both garlic and NSAIDs affect platelet function; concurrent use may increase the risk of gastrointestinal bleeding.

Dietary Advice

Foods and dietary considerations when taking Da Suan

Avoid eating garlic on an empty stomach, as its pungent, irritating nature can cause gastric discomfort, nausea, and burning sensations. Taking it with or after meals reduces stomach irritation. Adding vinegar when eating raw garlic can help mitigate its pungent irritation and may reduce the risk of adverse effects. Avoid excessive consumption of other acrid-hot (辛热) foods such as chili peppers, raw ginger, and strong alcohol while using Da Suan medicinally, as combining multiple heating substances can easily generate internal Fire and injure the Stomach and Liver Yin. Those using garlic to treat Cold-Damp patterns should avoid cold, raw foods that would counteract its warming effect.

Botanical Description

Physical characteristics and morphology of the Da Suan source plant

Garlic (Allium sativum L.) is a perennial herbaceous plant of the Amaryllidaceae (formerly Liliaceae) family, Allium genus. It has narrow, flat, strap-shaped leaves that are pale green with a waxy surface. The leaves arise from a short, compressed stem disc (the basal plate). The solid, cylindrical flower stalk (scape) can reach up to 60 cm tall, and the lower half is sheathed by leaf bases. The umbel-like flower cluster is enclosed in a long-beaked membranous spathe that falls off early. The small flowers are typically pale pink to purple, with lance-shaped petals 3–4 mm long, though many cultivated varieties rarely flower and instead produce bulbils (small aerial bulblets) in the inflorescence. Flowering occurs in July in the Northern Hemisphere.

The underground bulb, which is the medicinal part, is globe-shaped to flattened-spherical, 3–6 cm in diameter, composed of 6–20 cloves (individual bulblets) arranged around a central residual flower stalk on the basal plate. The outer bulb is wrapped in several layers of white or pale purplish papery skin. Each clove has its own thin membrane and consists of white, fleshy, strongly pungent tissue. The plant has a fibrous root system and a distinctive, penetrating sulfurous odor when the tissue is crushed.

Sourcing & Harvesting

Where Da Suan is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Late spring to early summer (typically May to June), harvested 18–30 days after the garlic scapes are collected, when most leaves have dried and the upper leaves begin to droop

Primary growing regions

China is the world's largest garlic producer. The most renowned production area (道地药材 dào dì) is Jinxiang County, Shandong Province, known as the 'Garlic Capital of China,' famous for its large, white-skinned bulbs with rich flavor and high allicin content. Other major production regions include Lanling (Cangshan) in Shandong, Pizhou and Fengxian in Jiangsu, Zhongmu and Qixian in Henan, Pengxian in Sichuan, and Qishan in Shaanxi. Purple-skinned garlic (紫皮蒜) is traditionally considered more medicinally potent than white-skinned varieties. Garlic originated in Central Asia (modern Afghanistan, Uzbekistan, Kashmir region) and was introduced to China during the Western Han Dynasty by Zhang Qian from the Western Regions, hence its classical name 'Hu Suan' (胡蒜, 'foreign garlic').

Quality indicators

Good quality medicinal garlic bulbs should be plump, firm, and heavy for their size, with tightly packed cloves and intact outer papery skin. The cloves should be white, fleshy, and juicy when peeled, with a strong, pungent aroma that becomes immediately evident when crushed. Purple-skinned garlic (紫皮蒜) is traditionally considered superior for medicinal use due to its higher allicin content and stronger antimicrobial effect compared to white-skinned varieties. Fresh garlic is more potent than aged or stored garlic. Avoid bulbs that are soft, sprouting, moldy, dried out, or have dark discoloration. The cross-section of a fresh clove should be uniformly white and moist.

Classical Texts

Key passages from the classical Chinese medical texts that describe Da Suan and its therapeutic uses

《名医别录》 (Ming Yi Bie Lu)

"散痈肿䘌疮，除风邪，杀毒气。"

"It disperses abscesses and sores, eliminates Wind-evil, and kills toxic Qi."

《本草纲目》 (Ben Cao Gang Mu) — Li Shizhen

"其气熏烈，能通五脏，达诸窍，去寒湿，辟邪恶，消痈肿，化癥积肉食，此其功也。"

"Its Qi is intensely pungent. It can open the five Zang organs, reach all the orifices, expel Cold-Damp, ward off evil, resolve abscesses and swelling, and transform accumulations of food stagnation — these are its merits."

《本草从新》 (Ben Cao Cong Xin)

"大蒜辛热有毒，生痰动火，散气耗血，虚弱有热者切勿沾唇。"

"Da Suan is acrid-hot and has toxicity; it generates Phlegm and stirs Fire, disperses Qi and depletes Blood. Those who are weak and have Heat must never let it touch their lips."

《本草经疏》 (Ben Cao Jing Shu)

"辛温能辟恶散邪，故主除风邪，杀毒气......其功长于通达走窍，去寒湿，辟邪恶，散痈肿，化积聚，暖脾胃，行诸气。"

"Its acrid warmth can ward off evil and scatter pathogenic influences, thus it mainly eliminates Wind-evil and kills toxic Qi... Its strength lies in its ability to penetrate and reach the orifices, expel Cold-Damp, ward off evil, disperse swellings, transform accumulations, warm the Spleen and Stomach, and move the various forms of Qi."

Historical Context

The history and evolution of Da Suan's use in Chinese medicine over the centuries

Garlic has one of the longest recorded histories of any medicinal food, with documented use spanning over 5,000 years across civilizations. Ancient Egyptian, Greek, Roman, and Indian medical traditions all employed garlic therapeutically. In China, the plant was introduced by the diplomat Zhang Qian during the Western Han Dynasty (around 139 BCE) after his missions to Central Asia, earning it the name Hu Suan (胡蒜, 'foreign garlic') to distinguish it from the native Xiao Suan (小蒜, small garlic or Allium macrostemon). The earliest Chinese reference to any garlic appears in the Xia Xiao Zheng (夏小正), which mentions the small native variety.

Li Shizhen's Ben Cao Gang Mu provides the most detailed classical discussion, praising garlic's ability to penetrate all organs and orifices while also warning of its capacity to injure the Liver and eyes with prolonged overuse. The Yuan Dynasty agriculturalist Wang Zhen extolled it as an indispensable staple for northern diets, claiming it could neutralize toxins in preserved meat and protect travelers from pestilence. Garlic also holds a notable place in Chinese Buddhist and Daoist tradition as one of the 'Five Pungent Vegetables' (五辛 wu xin), forbidden during spiritual practice for its supposed ability to disturb the mind and agitate desire. However, even Buddhist texts acknowledge its medicinal value when used strictly as treatment rather than food.

The character 蒜 itself is an ideogram originally applied to small garlic, which was said to often grow in pairs. When the larger Western variety arrived, 'Da' (大, big) was simply prefixed to distinguish it. In folk medicine, garlic's use as a topical agent for moxibustion (蒜钱灸, garlic-coin moxibustion) was widely practiced for treating abscesses and boils, a technique detailed in the surgical classic Wai Ke Jing Yao (外科精要).

Modern Research

4 published studies investigating the pharmacological effects or clinical outcomes of Da Suan

1

Comprehensive Meta-Analysis of Garlic on Cardiovascular Risk Factors in Adults (2026)

Behrouz V, Zahroodi M, Clark CCT, Mir E, Atashi N, Rivaz R. Nutrition Reviews. 2026;84(1):1-35.

This large meta-analysis pooled 108 RCTs with 7,137 participants and found that garlic supplementation significantly improved triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol, blood pressure, and fasting blood glucose, particularly in adults with unfavorable baseline risk profiles.

Link
2

Garlic Consumption and Dyslipidemia Risk: Meta-Analysis of RCTs (2024)

Journal of Health, Population and Nutrition. 2024;43:113.

A meta-analysis of 21 RCTs examining garlic's effect on blood lipids in patients with dyslipidemia found significant reductions in total cholesterol, triglycerides, and LDL cholesterol, with a slight increase in HDL cholesterol.

Link
3

Adverse Effects and Drug Interactions of Garlic in Humans: Review (2007)

Borrelli F, Capasso R, Izzo AA. Molecular Nutrition & Food Research. 2007;51(11):1386-1397.

A comprehensive review of clinical data found that the most common side effects of garlic are breath and body odor. Case reports documented allergic reactions, altered platelet function with possible bleeding risk, and skin burns from topical application. The review also noted potential interactions with anticoagulants and HIV protease inhibitors.

PubMed
4

Aged Garlic Extract on Blood Pressure and Lipid Profile: Dose-Response Meta-Analysis (2025)

Bashiri S, TaghipourSheshdeh F, Foshati S, Askarpour M, Ahmadi A, Babajafari S. Phytotherapy Research. 2025;39(12):5669-5694.

A systematic review of 19 RCTs found that aged garlic extract significantly reduced systolic blood pressure by 2.49 mmHg and LDL cholesterol by 4.41 mg/dL, with a dose-response relationship observed for LDL reduction.

Link

Research on individual TCM herbs is growing but still limited by Western clinical trial standards. These studies provide emerging evidence and should be considered alongside practitioner expertise.