Herb Bark (皮 pí / 树皮 shù pí)

Mu Jin Pi

Hibiscus Bark · 木槿皮

Hibiscus syriacus L. · Cortex Hibisci

Also known as: Chuan Jin Pi (川槿皮)

Mu Jin Pi is the bark of the Hibiscus shrub, traditionally used to treat skin infections like ringworm and to relieve itching. When taken internally, it clears damp-heat from the digestive tract to stop diarrhea and dysentery, and is also used to address yellow, foul-smelling vaginal discharge.

Category Herbs that attack toxins, kill parasites, and relieve itching (攻毒杀虫止痒药) Heat-clearing and damp-draining herbs (清热利湿药)
Therapeutic focus Skin health Digestive health Women's health

TCM Properties

Temperature

Cool

Taste

Sweet (甘 gān), Bitter (苦 kǔ)

Channels entered

Liver, Spleen, Large Intestine

Parts used

Bark (皮 pí / 树皮 shù pí)

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 Mu Jin Pi does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Mu Jin Pi is primarily used to support these areas of health:

Skin health Digestive health Women's health

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Mu Jin Pi performs to restore balance in the body:

Clears Heat and drains Dampness Kills parasites and relieves itching Clears Heat and resolves toxicity Invigorates Blood and moistens dryness

How these actions work

Clears Heat and drains Dampness: This means the herb helps remove excess heat and moisture from the body, especially from the digestive tract and lower body. It is used when there is heat-dampness causing diarrhea, dysentery, or vaginal discharge with yellow secretions.

Kills parasites and relieves itching: Mu Jin Pi is particularly effective against skin parasites, including fungi and scabies mites, when applied externally. It calms severe itching and clears the skin lesions.

Clears Heat and resolves toxicity: It eliminates toxic heat that can cause boils, carbuncles, and inflammatory skin conditions, helping to reduce swelling and promote healing.

Invigorates Blood and moistens dryness: This herb can stimulate blood circulation and has a moistening effect that benefits dry, scaly skin conditions and may help with certain types of blood stasis. Its mild blood-moving action is noted in classical texts for supporting tissue repair.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Mu Jin Pi is used to help correct these specific patterns.

Why Mu Jin Pi addresses this pattern

Mu Jin Pi's bitter taste dries dampness and its cool nature clears heat, directly targeting the damp-heat pathogen lodged in the large intestine. It enters the Large Intestine channel and effectively dispels damp-heat to stop diarrhea, dysentery, and tenesmus. Its mild astringency also helps reduce intestinal secretions.

A practitioner would look for one or more of these signs

Diarrhea

watery or mucoid stools

Dysentery

blood and mucus in stool

Rectal Prolapse

anal protrusion due to damp-heat dragging down

Commonly Used For

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

Arises from: Toxic-Heat

TCM Interpretation

In TCM, ringworm is seen as external invasion of damp-heat and toxins, often with wind and blood dryness. The skin becomes red, scaly, and itchy due to pathogenic heat and dampness. Mu Jin Pi primarily addresses the damp-heat and parasite (fungal) aspect.

Why Mu Jin Pi Helps

Mu Jin Pi's anti-fungal and anti-parasitic properties, combined with its cooling, drying nature, directly combat the damp-heat fungus. When applied topically, it kills the pathogen and relieves the intense itching that accompanies ringworm. Its traditional external use for '疥癣' makes it a classic remedy.

Also commonly used for

Diarrhea

Clears damp-heat from the intestines to stop diarrhea; used for acute infectious diarrhea with foul-smelling stool.

Eczema

Dries dampness and clears heat; used externally to reduce weeping and itchiness.

Rectal Prolapse

Reduces damp-heat dragging down to assist in returning protruding tissue.

Skin Itching

Alleviates pruritus from various dermatoses due to its parasiticide and anti-pruritic effects.

Hemorrhoids

Soothes swollen, painful piles by clearing heat and dampness.

Herb Properties

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

Temperature

Cool

Taste

Sweet (甘 gān), Bitter (苦 kǔ)

Channels Entered

Liver Spleen Large Intestine

Parts Used

Bark (皮 pí / 树皮 shù pí)

Dosage & Preparation

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

Standard dosage

3–9g

Maximum dosage

Up to 15g in decoction under practitioner supervision; exceeding this may cause gastrointestinal discomfort.

Dosage notes

Internal decoction: 3–9g. For external use, 15–30g may be used for washing or as a vinegar‑mixed paste. Lower doses (3–6g) suit mild damp‑heat; higher doses (9–15g) may be employed for stubborn skin conditions under professional guidance. Avoid prolonged use in patients with Spleen‑Stomach deficiency.

Preparation

For external use, the dried bark is often ground to powder and mixed with vinegar to form a paste. For internal decoction, add to boiling water and simmer for 20–30 minutes.

Processing Methods

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

Processing method

Fresh bark is cleaned, sliced or cut into strips, and dried in a well‑ventilated place out of direct sunlight.

How it changes properties

Maintains the natural cold nature and strongest insecticidal, antipruritic actions.

When to use this form

Preferred for external applications and for acute damp‑heat conditions where the full cooling, detoxifying power is needed.

Common Herb Pairs

These ingredients are traditionally combined with Mu Jin Pi for enhanced therapeutic effect

Huang Lian
Huang Lian 2:1 (Mu Jin Pi 12g, Huang Lian 6g)

Huang Lian's strong heat-clearing and damp-drying action synergizes with Mu Jin Pi's dampness-draining and anti-diarrheal effect, powerfully clearing damp-heat from the gastrointestinal tract to stop diarrhea and dysentery.

When to use: Acute dysentery or diarrhea with foul-smelling mucus and blood, abdominal pain, and burning sensation in anus due to damp-heat in the large intestine.

Huang Bo
Huang Bo 1:1 (Mu Jin Pi 10g, Huang Bo 10g)

Together they clear damp-heat, especially from the lower body, and relieve toxicity. Huang Bo drains fire and dries dampness, while Mu Jin Pi adds parasiticide and anti-itching actions.

When to use: Damp-heat patterns causing vaginal discharge with yellow, foul-smelling leucorrhea, or damp-heat skin conditions with weeping lesions.

Comparable Ingredients

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

Ku Shen
Mu Jin Pi vs Ku Shen

Both herbs clear damp-heat and kill parasites to relieve itching, but Ku Shen is more intensely bitter and cold, strongly clearing heart and liver fire and used for severe damp-heat dysentery and eczema. Mu Jin Pi is milder, enters the Large Intestine channel specifically, and has a lubricating, blood-moistening effect, making it more suitable for mild to moderate cases with dry skin or chronic conditions.

Identity & Adulterants

Related species and common adulterations to be aware of when sourcing Mu Jin Pi

May be confused with bark of other Hibiscus species, especially Hibiscus rosa‑sinensis (朱槿) and Hibiscus cannabinus (大麻槿). Authentic Mu Jin Pi has thinner bark, larger irregular lenticels, and a distinct chemical fingerprint. Modern DNA‑based methods (allele‑specific PCR) can reliably distinguish the genuine species from its adulterants.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Mu Jin Pi

Non-toxic

Although traditionally classified as non‑toxic (《本草纲目》载无毒), a few regional materia medica texts (e.g., 《南宁市药物志》) list it as having slight toxicity. Prolonged high‑dose oral administration may increase the load on liver and kidneys. Use standard dosages and avoid long‑term self‑medication.

Contraindications

Situations where Mu Jin Pi should not be used or requires extra caution

Caution

无湿热者不宜服 (should not be taken in the absence of damp-heat patterns)

Caution

脾胃虚弱者慎用 (use with caution in cases of Spleen-Stomach deficiency)

Avoid

过敏体质者慎用，已知对木槿皮过敏者禁用 (allergic individuals should use with caution; those with known allergy to Mu Jin Pi are prohibited)

Caution

孕妇及哺乳期妇女应在医师指导下使用 (pregnant and breastfeeding women should use only under professional guidance)

Caution

儿童使用需经专业医师评估 (use in children requires professional evaluation)

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Safety during pregnancy has not been adequately studied. Due to its cooling and dampness‑draining nature, it should only be used under the direction of a qualified TCM practitioner. Self‑medication is not recommended.

Breastfeeding

No safety data are available for breastfeeding. It may be excreted in breast milk; therefore, use only under professional supervision and avoid self‑administration.

Children

Use in children must be supervised by a professional. Dosage should be reduced proportionally based on body weight and age. Not suitable for unsupervised home use.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Mu Jin Pi

No well‑documented drug interactions are reported. Caution is advised when combining with other hypoglycemic or diuretic agents, as the herb’s cooling and dampness‑eliminating effects may produce additive actions. Always inform your healthcare provider of all concurrent medications.

Dietary Advice

Foods and dietary considerations when taking Mu Jin Pi

While taking Mu Jin Pi for damp‑heat conditions, avoid greasy, spicy, and raw cold foods that can generate or aggravate dampness and heat. Alcohol should be avoided during treatment, especially for skin disorders.

Botanical Description

Physical characteristics and morphology of the Mu Jin Pi source plant

木槿 (Hibiscus syriacus L.) is a deciduous shrub or small tree usually 3–5 m in height, with upright, much-branched stems that are covered with yellowish stellate hairs when young. Leaves are alternate, simple, ovate to rhombic, often shallowly 3‑lobed, with coarsely toothed margins and three prominent veins. The showy flowers are solitary in the leaf axils, with 5 petals (sometimes double in cultivars) ranging from white and pink to purple; each flower lasts only a day but the plant flowers continuously from June to October. Fruits are ellipsoid, hairy capsules containing black, kidney‑shaped seeds. The medicinal bark is harvested from the stems or roots. Native to East Asia, it is widely cultivated as an ornamental hedge plant and naturalized in many warm regions.

Sourcing & Harvesting

Where Mu Jin Pi is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Autumn, when the sap descends; bark is stripped from stems and roots of plants at least 3‑4 years old.

Primary growing regions

Originally from central China; widely cultivated in East, Central, South, and Southwest China. The best quality (道地药材) is traditionally considered to be from Sichuan province (known as 川槿皮).

Quality indicators

Good quality Mu Jin Pi is thin, smooth, and externally grayish‑brown with prominent lenticels. It should be free of decay and extraneous matter. The Sichuan‑produced material (川槿皮) is slightly thicker and considered superior. When broken, the cross‑section is fibrous; taste is slightly bitter and astringent.

Classical Texts

Key passages from the classical Chinese medical texts that describe Mu Jin Pi and its therapeutic uses

《本草纲目》
原文：木槿皮及花，并滑如葵花，故能润燥。色如紫荆，故能活血。川中来者，气浓力优，故尤有效。
译文：Mu Jin Pi and flowers are slippery like a sunflower, hence they can moisten dryness. Their color resembles that of Chinese redbud, hence they can invigorate Blood. Those from Sichuan have stronger qi and superior effect, so they are especially effective.

原文：气味甘，平，滑，无毒。大明曰：凉。主治止肠风泻血，痢后热渴，作饮服之，令人得睡，并炒用。治赤白带下，肿痛疥癣，洗目令明，润燥活血。
译文：Sweet, bland, slippery, non‑toxic. Daming says: cool. It stops intestinal wind bleeding, thirst after dysentery; taken as a drink it promotes sleep, and can be dry‑fried. It treats red and white vaginal discharge, swelling and pain, scabies and ringworm; washing eyes clears vision; it moistens dryness and invigorates Blood.

Historical Context

The history and evolution of Mu Jin Pi's use in Chinese medicine over the centuries

The use of Mu Jin Pi was first recorded in the Tang dynasty's Bencao Shiyi (《本草拾遗》) as a treatment for intestinal wind bleeding. In the Ming dynasty, Li Shizhen's Bencao Gangmu (《本草纲目》) consolidated its properties and added that it moistens dryness and invigorates blood. Li noted that bark from Sichuan (川槿皮) was of superior quality. The plant itself — 木槿 — has ancient cultural roots: it appears as '蕣' in the Shijing (《诗经》) and later became the national flower of South Korea (무궁화, mugunghwa), symbolizing perseverance due to its long flowering season. In Chinese folk medicine, the bark has been a household remedy for skin ailments, often applied as a vinegar paste, and was included in the surgical classic Waike Zhengzong (《外科正宗》) as an ingredient in ointments for tinea and scabies.

Modern Research

A published study investigating the pharmacological effects or clinical outcomes of Mu Jin Pi

1

Research progress in functional nutrients and biological activities of Hibiscus syriacus L. (Review, 2017)

ZHANG Wenyan, WANG Xiaohong, LI Anping, et al. Food and Machinery, 2017, 33(2): Article 45.

This review summarizes the functional nutrients (flavonoids, organic acids, coumarins, sterols) and biological activities of Hibiscus syriacus, including antioxidant, anti‑inflammatory, antimicrobial, antihyperglycemic, antihypertensive, and anticancer effects, providing scientific support for the medicinal use of the bark.

DOI

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.