DOWNWARD-DRAINING

HERBS

Revised: 8/28/2019

Sources:
• Bensky, D. (2004). Chinese Herbal Medicine: Materia Medica. Seattle, WA: Eastland Press. pp. 235-263

• Chen, J. and Chen, T. (2004). Chinese Medical Herbology and Pharmacology. Art of Medicine Press. pp. 256-297

Downward-Draining Herbs
Downward-Draining Herbs promote movement through the large intestine. This can
be done to relieve constipation, or as a way to drain heat out of the body.

Purgatives - These herbs strongly induce diarrhea and should not be used with seniors,
children, or people with a weak constitution. They are typically bitter and cold, and they
treat constipation due to heat.

Moist Laxatives - These herbs tend to be oily seeds. Unlike Purgatives, Moist Laxatives
gently relieve constipation and may take some time to work.

Harsh Expellants - These herbs are very strong an usually toxic. They should only be used
in small doses, and only if the patient is strong enough to take them.

Harsh Expellants induce watery diarrhea to treat severe edema in the chest and abdomen
(e.g. pleurisy, ascites). Three of Gan Cao’s incompatible herbs belong to this category (Gan
Sui, Da Ji, Yuan Hua).
 Downward-Draining Herbs

PURGATIVES: MOIST LAXATIVES: HARSH EXPELLANTS:

• dà huáng
• huǒ má rén
• gān suì

• máng xiāo
• yù lǐ rén
 • qiān niú zǐ

• fān xiè yè
• dà jǐ

• lú huì
• bā dòu

Downward Draining Herbs

Purgatives Moist Laxatives Harsh Expellants

Taste: • bitter • sweet • toxic

Temperature: • cold • neutral • cold (or hot)

Channels: • LI • LI • LI, KI, LU

Cautions & 
 Use caution in Use caution in

Contraindications: deficiency/pregnancy deficiency/pregnancy

Moisten LI to gently
Main Action: Purge LI, clear heat Purge water
relieve constipation
dà huáng
rhei radix et rhizoma
⼤大
Temp: cold

Taste: bitter

Channels: HT, LI, LV, ST

Dosage: 3-15 grams (for purgative effect, cook only 3-5 min.)
⻩黄
1. purges Large Intestine to relieve constipation

• for Yang Ming Bowel disease (fever, constipation, abdominal pain)

2. clears heat and drains fire

• for heat in the intestines and upper body (fever, sore throat, painful
eyes)

• cools blood to stop bleeding (hemorrhoids, blood in stool); use charred

3. invigorates blood

• for fixed, sharp pain; abdominal masses; 


amenorrhea due to stagnation

• for injury and trauma (can be used externally)

4. dries dampness to relieve jaundice

dà huáng
rhei radix et rhizoma
⼤大
(continued)

• Because it is so strong, Da Huang is nicknamed The General (Jian Jun)

⻩黄
• Da Huang is used for Yang Ming Bowel disease, characterized by heat bind in the
Stomach and Large Intestine, abdominal pain that worsens with pressure, and
constipation

• Because it purges the Large Intestine, clears heat, invigorates blood, and stops bleeding,
Da Huang is especially useful for Large Intestine abscess and appendicitis

• Da Huang is so strong at invigorating blood, it is said that it “cracks the blood.” Because
of its strong moving action and its strong downward action, it is contraindicated during
pregnancy
• Use caution during breastfeeding, as its purgative effect may come through in the
breastmilk

• Da Huang can used in its charred form to stop bleeding, especially for hemorrhoid and
blood in the stool. This is useful because it can stop bleeding without causing stagnation.

• Da Huang is so good and invigorating blood and clearing heat, it can be used topically
for injury and trauma when there is redness, swelling and heat, as in San Huang San
(nicknamed Herbal Ice)
máng xiāo
natrii sulfus
芒
Temp: very cold

Taste: acrid, bitter, salty

Channels: ST, LI

Dosage: 6-18 grams (stir in at end)

硝
1. softens hardness to relieve constipation

• commonly used with Da Huang to purge the Large Intestine

2. clears heat toxicity

• for acute appendicitis, Large Intestine abscess

• used internally or externally to treat skin problems

• for early stage breast abscess, poor lactation

Mang Xiao is gluaber’s salt (sodium sulfate). It’s salt, so it’s salty in flavor.

Mang Xiao is also contraindicated during pregnancy.

fān xiè yè
sennae folium
番
Temp: cold

Taste: sweet, bitter

Channels: LI

Dosage: 1.5-3 grams (prepare as tea; dosage can be adjusted by patient)

泻
1. purges Large Intestine to relieve constipation

• promotes movement in Large Intestine

叶
• often used as single herb

Fan Xie Ye is senna leaf. It can be prepared as a tea, with the dosage and steeping time adjusted 

by the patient (too strong and it may cause abdominal cramping).
lú huì
aloe
芦
Temp: cold

Taste: bitter

Channels: LI, LV, ST

Dosage: 1.5-4.5 grams (used in pills or tablets; do not decoct)

荟
1. purges Large Intestine to relieve constipation

2. strongly clears heat from Liver and Gallbladder

• for dizziness, headaches, tinnitus, red eyes, irritability

3. kills Large Intestine parasites

• esp. for roundworms; also for tinea

This is the dried, bitter latex from the outer leaf of the aloe plant. It is completely different from aloe vera gel. 

It is especially useful for constipation due to Liver heat, or with parasites.

Since Lu Hui is so strong at both purging the Large Intestine and draining heat, it is usually used as a last resort 

after more gentle herbs have proved ineffective. Lu Hui is contraindicated in pregnancy. It can be excreted though 

breastmilk and act as a purgative for a breastfeeding baby.

huǒ má rén
cannabis semen
⽕火
Temp: neutral

Taste: sweet

Channels: LI, SP, ST

Dosage: 9-15 grams (crush before decocting)

麻
1. moistens Large Intestine to relieve constipation

• for dry constipation due to yin or blood deficiency

仁
• for constipation after febrile disease, in the elderly, or postpartum

2. nourishes yin

3. clears heat and heals sores

• used internally or externally for mouth sores 


due to Stomach heat

• mild; used as an auxiliary herb

Overuse of Huo Ma Ren can cause upset stomach or mild shen problems (agitation, restlessness, confusion).
yù lǐ rén
pruni semen
郁
Temp: neutral

Taste: acrid, bitter, sweet

Channels: LI, SI, SP

Dosage: 3-9 grams (crush before decocting)

李李
1. moistens Large Intestine to relieve constipation

• esp for constipation due to dryness or qi stagnation

仁
2. promotes urination to treat edema

• mild; used as an auxiliary herb

gān suì
kansui radix
⽢甘
Temp: cold

Taste: bitter, sweet, toxic

Channels: KI, LI, LU

Dosage: 0.5-1.5 grams

遂
1. induces watery diarrhea to treat edema

• for severe accumulation of fluid in the chest and abdomen

• for general edema, facial edema, abdominal distention

2. drives out phlegm

• for severe phlegm accumulation, e.g. seizures due to 


wind-phlegm, shen problems due to phlegm

3. used topically to reduce swelling

• for skin problems due to damp-heat

“This is a violent, cathartic herb that causes one to pass water anally.” -Bensky

Contraindicated during pregnancy.

qiān niú zǐ
pharbitidis semen
牵
Temp: cold

Taste: bitter, acrid, slightly toxic

Channels: KI, LI, LU, SI

Dosage: 3-6 grams in decoction (crush before decocting); 1.5-3 grams as powder
⽜牛
1. drains water and promotes urination

• expels water through both the urine and the stool

⼦子
• esp. for edema in the Lung, ascites

• for damp-heat or food stagnation in the Stomach and Intestines

2. drives out phlegm

• for cough, wheezing, fullness in chest due to 


thin mucus in the Lung

3. kills Large Intestine parasites

• for roundworm and tapeworm

This is morning glory seed. Contraindicated during pregnancy.

dà jǐ
knoxiae/euphorbiae radix
⼤大
Temp: cold

Taste: bitter, acrid, toxic

Channels: KI, LI, SP

Dosage: 1.5-3 grams

戟
1. induces watery diarrhea to treat edema

• for accumulation of fluids in the chest and flank

2. use externally to clear heat toxicity

• for red, swollen, painful sores or scrofula

Da Ji can refer to two different herbs: Hong Da Ji (knoxiae radix) or Jing Da Ji (euphorbiae pekinensis radix).

They have the same properties, except Jing Da Ji is stronger and more toxic.

Jing Da Ji is incompatible with Gan Cao.

These are different from Da Ji (cirsii japonici radix) which stops bleeding.
bā dòu
crotonis fructus
巴
Temp: hot

Taste: acrid, toxic

Channels: ST, LI, LU

Dosage: 0.1-0.3 grams (used in pills or tablets; do not decoct)

⾖豆
1. drains cold stagnation downward

• for constipation, abdominal fullness and pain due to cold

2. drives water retention in chest and abdomen

• for ascites, e.g. in end-stage schistosomiasis (parasitic worms)

3. expels cold-phlegm

• for throat obstruction, shen problems due to phlegm

4. used topically to treat skin problems

• promotes healing of abscesses and ulcers

Contraindicated during pregnancy. 20 drops of oil from Ba Dou can be fatal due to fluid loss.

“Traditionally, it was regarded as the herbal equivalent of a battering ram.” -Bensky

Summary
da huang
purges Large Intestine
• invigorates blood

rhei radix et rhizoma • drains heat through intestines • dries dampness (jaundice)

mang xiao
purges Large Intestine
• clears heat toxicity
natrii sulfus • softens hardness

fan xie ye
purges Large Intestine

sennae folium • promotes movement

lu hui
purges Large Intestine
• clears LV/GB heat

aloe • kills LI parasites

huo ma ren
moistens Large Intestine
• nourishes yin
cannabis semen

yu li ren
moistens Large Intestine

pruni semen

gan sui
induces diarrhea to treat edema
• drives out phlegm

kansui radix • topically for swelling

qian niu zi
induces diarrhea and promotes urination • drives out phlegm

pharbitidis semen to treat edema

• kills LI parasites

da ji
induces diarrhea to treat edema
• clears heat toxicity
knoxiae/euphorbiae radix

ba dou
drains cold stagnation
• topically for skin problems
crotonis fructus