English: Sophora roots

Chinese: 苦参

Parts used: Dried root

TCM category: Herbs that clear Heat and dry Dampness

TCM nature: Cold

TCM taste(s): Bitter

Organ affinity: Bladder Heart Large intestine Liver Stomach

Scientific name: Sophora flavescens

Other names: Shrubby sophora

Use of Ku Shen (sophora roots) in TCM

Please note that you should never self-prescribe TCM ingredients. A TCM ingredient is almost never eaten on its own but as part of a formula containing several ingredients that act together. Please consult a professional TCM practitioner, they will be best able to guide you.

Preparation: Remove the smaller roots, wash, soak thoroughly in water, cut into thick slices, dry.

Dosage: 3 - 12 grams

Main actions according to TCM*: Expels Damp-Heat. Scatters Wind and relieves itching.Promotes urination and expels Heat. Kills parasites. Applied externally for Damp-Heat.

Primary conditions or symptoms for which Ku Shen may be prescribed by TCM doctors*: Dysentery Hematochezia Jaundice Oliguria Leukorrhea Eczema Sores Rashes Scabies Carbuncles Vaginitis Urinary tract infection Ringworm

Contraindications*: This herb should not be used by those with weakness and Cold in the Spleen and Stomach. This is a toxic herb, it should be used with care and prescribed by professional TCM practitioners.

Common TCM formulas in which Ku Shen is used*

Ku Shen Tang

Source date: 1806 AD

Number of ingredients: 8 herbs

Formula key actions: Dispels Wind. Dries Dampness. Kills parasites. Relieves itching.

Conditions targeted*: Atopic dermatitisSeborrheic dermatitis and others

Ku Shen is a king ingredient in Ku Shen Tang. Like the name indicates, it means it has more power than other ingredients in the formula.

In Ku Shen Tang, Ku Shen disperses Wind, kills parasites and stops itching topically. It is effective in treating general itching or vaginitis due to trichomonas infection, together with Phellodendron bark and Cnidium Seed. 

Read more about Ku Shen Tang

Xiao Feng San

Source date: 1617 AD

Number of ingredients: 13 herbs

Formula key actions: Disperses Wind. Eliminates Dampness. Clears Heat. Cools the Blood.

Conditions targeted*: UrticariaEczema and others

Ku Shen is a deputy ingredient in Xiao Feng San. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Xiao Feng San, Ku Shen is an effective herbs for itchiness from Damp-Heat. It also kills parasites and resolves toxicity. 

Read more about Xiao Feng San

Key TCM concepts behind Ku Shen's properties

In Traditional Chinese Medicine (TCM), Ku Shen belongs to the 'Herbs that clear Heat and dry Dampness' category. Herbs in this category are used to clear inflammatory and infectious conditions, referred to as 'Internal Heat' in TCM. This is why most of the herbs in this category will have both antibacterial and antiviral properties. In TCM one has too much 'Internal Heat' in their body as a result of a deficiency of 'Yin' (which is Cold in nature, see our explanation on Yin and Yang) or, more commonly, an Excess of Yang (Hot in nature). Herbs that clear Heat and dry Dampness treat the latter while, at the same time, relieving the body of excess Dampness. As such they tend to be Cold or Neutral in nature.

As suggested by its category Ku Shen is Cold in nature. This means that Ku Shen typically helps people who have too much 'Heat' in their body. Balance between Yin and Yang is a key health concept in TCM. Those who have too much Heat in their body are said to either have a Yang Excess (because Yang is Hot in nature) or a Yin deficiency (Yin is Cold in Nature). Depending on your condition Ku Shen can help restore a harmonious balance between Yin and Yang.

Ku Shen also tastes Bitter. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Bitter ingredients like Ku Shen tends to have a cleansing action on the body by clearing Heat, drying Dampness and promoting elimination via urination or bowel movements.

The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such Ku Shen is thought to target the Bladder, the Heart, the Large intestine, the Liver and the Stomach. In TCM the impure water collected by the Kidneys that cannot be used by the body is sent to the Bladder for storage and excretion as urine. In addition to regulating Blood flow, the Heart is believed to be the store of the 'Mind' which basically refers to someone's vitality. The Large Intestine receives the "impure" parts of the digested food from the Small Intestine, absorbs the remaining fluids and excrete the remainder as feces. The Liver is often referred as the body's "general" because it is in charge of regulating the movements of Qi and the Body Fluids. It also takes a leading role in balancing our emotions. The Stomach is responsible for receiving and ripening ingested food and fluids. It is also tasked with descending the digested elements downwards to the Small Intestine.

Research on Ku Shen

Sophora has anti-inflammatory and antioxidant properties.1

Sophora flavescens may have the potential for treatment of chronic inflammatory disorders such as rheumatoid arthritis.2

Sophora could possibly be used as a treatment for mast cell-derived allergic inflammatory diseases.3

Sophora may be an effective cholesterol-lowering agent and useful for preventing hypercholesterolemic atherosclerosis.4


1. Dong H.L., Dong S.S., Dai Y.C., Beom J.K., Yun Y.L., Young H.K. "Anti-inflammatory and anti-oxidant effects of Sophora flavescens root extraction in lipopolysaccharide-activated raw 264.7 cells", Korean Journal of Medical Mycology 2010 15:2 (39–50)

2. Jin J.H., Kim J.S., Kang S.S., Son K.H., Chang H.W., Kim H.P."Anti-inflammatory and anti-arthritic activity of total flavonoids of the roots of Sophora flavescens" Journal of Ethnopharmacology 2010 127:3 (589–595)

3. Hong, M.H.; Lee, J.Y.; Jung, H.; Jin, D.-H.; Go, H.Y.; Kim, J.H.; Jang, B.-H.; Shin, Y.-C.; Ko, S.-G (2009). "Sophora flavescens Aiton inhibits the production of pro-inflammatory cytokines through inhibition of the NF κB/IκB signal pathway in human mast cell line (HMC-1)". Toxicology in Vitro. 23 (2): 251–258. doi:10.1016/j.tiv.2008.12.002.

4. Kim H.Y., Jeong M., Jung H.J., Jung Y.J., Yokozawa T., Choi J.S."Hypolipidemic effects of Sophora flavescens and its constituents in poloxamer 407-induced hyperlipidemic and cholesterol-fed rats." Biological & pharmaceutical bulletin 2008 31:1 (73–78)