Skin profile
Where this herb sits in skin practice: the pattern it corrects, the skin signs it suits, and what it should not be used for.
Shi Chang Pu is a drying aromatic for dampness that shows on the skin and in the mind at once: moist itchy folds, a greasy scalp and the night itch that keeps a person awake. It is warm and drying, so it is wrong in a dry constitution and after fluid loss, and the asarone question is a reason to keep the dose ordinary and the course short rather than a reason to avoid an ordinary decoction.
Skin signs that suggest it
- A moist, itchy fold or crease that stays damp, with a thick greasy tongue coating and a heavy head
- A greasy, itchy scalp with an odour, worse after sleep and in humid weather
- Itch that is worse at night, with restlessness, broken sleep and a feeling of mental clouding
- A red brown, itchy genital or anal area with moisture, in a person who feels heavy and dull rather than hot and thirsty
- A greasy coating on the tongue, a slippery pulse and heaviness in the limbs alongside the skin complaint
When it is not the right herb
Not for a dry constitution. Being warm, acrid and drying, it takes fluid from anyone whose Yin is already low and who shows heat: sweating at night, flushing, a red tongue without coat, thirst, irritability. The skin can end up drier and the itch worse. It is wrong after sweating, vomiting or a dry cough has depleted fluids, and it is not for a red, hot, spreading eruption or a weeping lesion with a bright red base and thirst, where cooling herbs lead. It is used with caution in active ulcer disease, because it stimulates digestive secretions, and large doses are avoided in pregnancy. A persistent itch with weight loss, jaundice or a new rash needs medical assessment, and a chronic itch that disturbs sleep should be examined rather than treated for months with a drying aromatic.
What it does for skin
Skin-relevant actions only. Each one describes a mechanism in TCM terms and what it looks like on the skin.
Dries Dampness that shows as a moist, greasy surface
A fold that never dries, a scalp that is greasy and stale, an itch that is worse in humid weather, all belong to Dampness rather than to heat. The rhizome is warm, acrid and bitter, so it moves the dampness, dries it and keeps the middle from cooling, and it is used where the lesion is moist without being bright red. It is a supporting dryer, weaker than the bitter rhizomes, and it is stopped when the surface dries.
Cuts through the turbidity that clouds the senses and the skin
Turbidity is the stale, cloudy quality that Dampness leaves behind: a thick coating, a muzzy head, a dulled sense of smell and a skin that looks and feels heavy rather than clean. The aroma is the active part, which is why the rhizome is added late in decoction and used in washes, and why it is held to clear a film from both the mind and the surface. It is the reason the herb appears in formulas for itch that comes with mental clouding.
Settles the spirit and breaks the itch and scratch cycle
Chronic itch and broken sleep reinforce each other, and a person who scratches at night keeps the plaque thick and the skin broken. The rhizome is one of the aromatic herbs used to calm the spirit, and in skin practice it is given with blood nourishing and wind settling herbs so that the night itch eases and the plaque can thin. It is a supporting action: emollients, antihistamines and treatment of the underlying condition do more, and the herb is not a substitute for them.
Transforms Phlegm that keeps a plaque thick and wet
A long standing, thickened, weeping plaque is read as Phlegm and Dampness bound into the tissue, and the rhizome is used to transform it rather than to dry the surface alone. It is combined with Pinellia and with herbs that move Blood, and the aim is to soften and thin what has become leathery and wet at once. A plaque that is growing, ulcerated or changing needs a dermatological opinion before any formula.
Skin conditions it is used for
Mapped to the condition pages on this site. The pattern column shows what the skin is doing when this herb is the right choice.
| Condition | Pattern | Why it suits | Typical setting |
|---|---|---|---|
| Neurodermatitis | Dampness and Phlegm with a disturbed spirit and a long itch and scratch cycle | A thickened, leathery plaque at the nape, the ankle or the forearm is the end point of a long cycle of itch and scratching, and in the damp pattern the plaque is also moist and the coating is thick. The rhizome dries the dampness, transforms the Phlegm bound into the tissue and calms the restlessness that drives the scratching, which is why it is paired with blood nourishing herbs rather than used alone. Behavioural measures and treatment of the underlying dryness or irritation remain the mainstay. | Within a formula with Dang Gui, Bai Shao and Ban Xia |
| Itchy Skin | Dampness with Wind, worse at night and in humidity | Itch that moves, worsens at night and comes with a heavy body and a greasy coating is read as Dampness with Wind. The rhizome dries the dampness, and its aroma is held to disperse the turbidity that keeps the itch going, while wind settling herbs address the movement. It is a supporting herb for the damp type, and a dry, pale, scaly itch points the other way and needs nourishment rather than drying. | Within a drying and wind settling formula with Ku Shen and Fang Feng |
| Itchy Genitalia | Dampness sinking into the lower orifices, with turbidity | Genital itch with moisture, a heavy feeling and a greasy coating is read as Dampness in the Liver channel and the lower orifices. The rhizome is used as a drying aromatic, internally and in a dilute wash, and it is combined with bitter cooling herbs when there is redness and with warming ones when there is not. Any persistent itch, discharge, bleeding or a new lump needs examination, and infection must be treated specifically. | Within a drying formula with Ku Shen and She Chuang Zi, or as a dilute wash |
| Anal Irritation | Dampness and Heat sinking to the lowest opening | The anus is where dampness and heat collect most easily, and itch there with moisture and a greasy coating is read as damp-heat sinking downward. The rhizome dries and moves the dampness, and it is used in a formula and in a wash with bitter cooling herbs. Bleeding, a new lump or persistent pain is a medical question first, and a wash is kept weak and cool rather than hot. | Within a drying formula with Huang Bo and Ku Shen, or as a cooled wash |
Combinations for skin
Herbs it is paired with when the skin, not an internal organ, is the target.
| Partner | Ratio | Why the pair is used |
|---|---|---|
| Yuan Zhi | 3 to 6 g each | The classical pair for poor memory with dampness, and in skin practice for itch that disturbs sleep. Yuan Zhi calms the spirit and opens the Heart, while the rhizome dries the dampness that clouds it, so the pair addresses the restlessness and the surface together. It is a gentle pair, used over weeks, and it is not a sedative. |
| Fu Ling | 9 to 12 g Fu Ling with 3 to 6 g Shi Chang Pu | Fu Ling drains dampness through the urine and strengthens the Spleen that made it, while the rhizome dries and disperses what has settled in the middle and on the surface. The pair is used for dampness clouded thinking with a moist, itchy skin, and it is one of the mildest ways to dry a damp constitution without exhausting it. |
| Ku Shen | 6 to 10 g Ku Shen with 3 to 6 g Shi Chang Pu | Ku Shen is cold and bitter and is the stronger herb against damp-heat itch, while the rhizome is warm and aromatic and better at moving turbidity. The pair is used for a moist, itchy fold or genital area where the redness is moderate, and the warmth of the rhizome keeps the cold root from stagnating the dampness. It is a short course, and a wash is kept dilute. |
| Ban Xia | 6 to 9 g each | Pinellia dries dampness and breaks Phlegm through the middle and lower body with an intensity this rhizome lacks, while the rhizome works upward on the orifices and the surface. Between them they clear Phlegm on more than one level, which is why they appear together for a thick, wet plaque and for itch with a mucky coating. Neither herb belongs in a dry constitution. |
Formulas where it leads
- Ku Shen Tang (苦参汤) - The classical wash for itching, from the Yang Ke Xin De Ji, in which this rhizome is one of eight herbs beside Ku Shen, She Chuang Zi, Bai Zhi, Huang Bo, Jin Yin Hua, Ye Ju Hua and Di Fu Zi. The formula is boiled and used cooled on the affected part, and it is the clearest traditional setting for the rhizome as a surface medicine rather than an internal one. It is a wash, not a drink, and it is used on limited areas for a short course.
Topical use
The rhizome is included in traditional washes for damp, itchy skin, most often as one member of a bitter, drying blend rather than on its own: 苦参汤 style washes for itch and weeping lesions list it alongside Ku Shen, Huang Bo, Bai Zhi and She Chuang Zi. The aromatic oil carries the action, so the decoction is kept covered and used the same day, and the wash is aimed at a moist, greasy surface rather than at an infection. It is kept weak, cool and limited to the area that itches.
| Preparation | How and when it is used |
|---|---|
| Dilute wash for folds and scalp | 10 to 15 g of dried rhizome, alone or with an equal part of Ku Shen, simmered in 1 litre of water for 15 minutes with the lid on, then strained and cooled to skin temperature. Apply with clean gauze for a few minutes once daily, rinse if the skin stings, and dry the area carefully. Make it fresh and discard leftovers. |
Patch test and cautions
Patch test on a small area of normal skin for 24 hours before first use, and do not apply to broken, cracked or ulcerated skin without supervision. Stop at once if burning, stinging or spreading redness develops. Keep the wash away from the eyes, the mouth and the genitals of a child, do not cover a treated area with an occlusive dressing, and do not use it on the breasts or abdomen in pregnancy. A wash does not treat an established infection, so a spreading or painful lesion needs medical care.
Safety for skin use
What to check before recommending or using it, including the cautions that matter most for skin patients.
Do not use, or use with caution
- Yin deficiency with rising Yang: flushing, night sweats, irritability, dizziness and a red tongue with little coating. The warm, acrid, drying rhizome consumes fluid that is already short.
- Loss of fluid through sweat, sickness or a dry cough, where the trouble is dryness and an aromatic dryer makes it worse.
- Dry, thin, scaly skin with no moisture and no greasy coating, and any red, hot, spreading eruption with thirst, where cooling herbs are needed instead.
- Active peptic ulcer disease, because the rhizome stimulates digestive secretions, and involuntary seminal loss, which the dispersing quality is said to aggravate.
- Pregnancy in large doses, and children under three without a practitioner, since large amounts quiet the nervous system and the asarone question is unresolved in a small body.
Pregnancy and breastfeeding
Used cautiously rather than freely. In laboratory work its asarones have acted on the uterus, and at high exposure they raise questions about genotoxicity. The old texts do not class the rhizome among the herbs that calm and support a pregnancy. It is generally avoided in pregnancy, and a topical wash is not used on the abdomen or the breasts. While breastfeeding there are no specific data: those asarones dissolve in fat and might in principle enter milk, and at higher doses the herb is sedating, so it is reserved for a clear indication, given at low dose, briefly, and with supervision.
Interactions
- Sedatives: laboratory work shows sedative and anticonvulsant effects, so benzodiazepines, barbiturates and other central depressants may cause deeper drowsiness and slower reactions when taken with the herb.
- Cholinesterase inhibitors: reports describe an effect on acetylcholine, so donepezil and similar drugs call for caution rather than an automatic ban, and the prescriber should know it is being taken.
- Iron: iron vessels were forbidden for preparing it, and the caution is commonly widened to iron tablets, on the view that the two cause nausea and cancel each other. Anticoagulants are a further theoretical worry, since the herb is said to move Blood.
Allergy and patch testing
Contact dermatitis to the volatile oil is possible, and a wash should be patch tested on a small area of normal skin for 24 hours. The greater practical risk is identity: Shui Chang Pu is a larger, spongier rhizome with a poorer oil, and Jiu Jie Chang Pu belongs to the buttercup family, is no Acorus, and carries its own toxicity, so material should be bought from a supplier who can name the species. Stop if the skin becomes more irritated rather than calmer.
General safety references
General references for herbal hepatotoxicity and herb-drug interactions; they are not specific to this herb.
- Review article: Herbal hepatotoxicity - an update on traditional Chinese medicine preparations. Alimentary Pharmacology & Therapeutics, 2014. PMID: 24844799.
- Interactions between herbal medicines and prescribed drugs: an updated systematic review. Drugs, 2009. PMID: 19719333.
- Warfarin and food, herbal or dietary supplement interactions: a systematic review. British Journal of Clinical Pharmacology, 2021. PMID: 32478963.
Evidence
The classical record is quoted with its source. The modern note states the level of evidence plainly.
Classical record
Pungent and warm, Chang Pu rules wind cold damp impediment and coughing with rising Qi, opens the openings of the Heart, builds the five viscera, opens the nine orifices, sharpens hearing and sight and gives the voice back. Used for a long time it lightens the body, keeps forgetfulness and confusion away, and lengthens life.
Shen Nong Ben Cao Jing (Divine Husbandman's Classic of Materia Medica), Han compilation - The line on wind cold damp impediment is the classical foothold for using the rhizome where dampness and cold have settled in the tissue, and the orifice work explains its pairing with the spirit.
The Qi of calamus is warm. It is used when Heart Qi is insufficient, since in deficiency the mother is supplemented.
Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen - Li Shizhen applies the five phase rule here: warming a herb is said to help the Heart by reinforcing the Liver that mothers it, which is why the herb is warm and drying in direction.
Only the rhizome that grows on stone works; grown elsewhere it does nothing at all. It may assist or guide but never take the leading place, and opening the Heart requires Ren Shen at its side.
Ben Cao Xin Bian (New Compilation of Materia Medica), Chen Shiduo - A blunt verdict on its rank, and the reason it partners other herbs in a skin formula instead of leading.
Modern evidence
Evidence status
- Laboratory work on the volatile oil, chiefly beta asarone and alpha asarone, reports sedative, anticonvulsant, antimicrobial and anti-inflammatory activity, mostly in animals and cell models. The same constituents carry the genotoxicity question, which is why the regulatory comparison below matters.
- Beta asarone at high concentration has caused concern about genotoxicity and liver toxicity in laboratory work, which is why the Council of Europe limits it to 1 mg per kg in alcoholic beverages. At an ordinary decoction dose the quantity is very small, but the comparison is the reason concentrated extracts and long high dose courses are avoided.
- No controlled trial of Shi Chang Pu in a skin condition was identified. The clinical literature is largely Chinese studies of formulas for cognitive and digestive complaints, and the skin uses here are extrapolated from the drying and Phlegm transforming actions rather than tested directly.
PubMed records
Selected real PubMed records for this herb's species or its constituents, chosen by species name and title relevance. They are references for the non-TCM discussion above, not proof that the herb treats any skin condition.
- Acorus tatarinowii Schott: A Review of Its Botany, Traditional Uses, Phytochemistry, and Pharmacology.. Molecules (Basel, Switzerland), 2023. PMID: 37299001 (pharmacology or review record).
- Therapeutic mechanisms of Acorus tatarinowii and its bioactive compounds in cardiovascular diseases: A comprehensive review.. Phytomedicine : international journal of phytotherapy and phytopharmacology, 2025. PMID: 40578036 (pharmacology or review record).
Dose and forms
Skin-practice dosing and the preparations that suit skin complaints.
| Form | Dose and notes |
|---|---|
| Decoction | 3 to 9 g of dried rhizome a day for skin complaints, added near the end with the lid on so the aromatic oil stays in the cup. |
| Powder and fresh rhizome | As a powder, 1 to 3 g a dose; the fresh rhizome is used at about twice the dried figure. The fresh form is preferred where the dampness is acute. |
| Dose by purpose | For opening work inside a formula, 3 to 6 g; where dampness blocks the middle with fullness at the epigastrium, 9 to 15 g under supervision. |
This is a modest amount of an aromatic rhizome, and at the usual decoction range the asarones are present only in traces: the regulatory limit concerns concentrated alcoholic products, not tea. The oil is the active part, so the rhizome is added late and the pot is kept covered, and a long boil sends the aroma out into the room instead of leaving it in the drink. Courses are short and reviewed, generally two to four weeks, and the dose is not raised to make a drying herb work faster.
Citations and further reading
Only real sources are listed: the classical materia medica passages quoted above, and the source works behind the botanical and safety statements.
- Shen Nong Ben Cao Jing (Divine Husbandman's Classic of Materia Medica), attributed compilation of the Han period - the entry on the orifices and on wind cold damp impediment is summarised above.
- Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen, 1578 - the note on Heart Qi and the five phase rule is summarised above.
- Ben Cao Xin Bian (New Compilation of Materia Medica), Chen Shiduo, Qing dynasty - the judgement on the rank of the rhizome is summarised above.
- Rhizoma Acori Tatarinowii monograph, Pharmacopoeia of the People's Republic of China - the accepted source, the part used and quality requirements.
- Council of Europe guidance on beta asarone in flavoured alcoholic beverages - the source of the 1 mg per kg comparison used above.
- Modern evidence statement: based on published laboratory work on the volatile oil and on the absence of identified skin trials, stated as a level of evidence rather than as a cited finding.
Educational reference for qualified practitioners. This page is not medical advice, and skin conditions should be diagnosed by a clinician before treatment.