Chan Tui (Circada Moulting)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Chan Tui, and what part is used?

  3–9 g in decoction — and the part used is the cast-off shell, not the insect. Chan Tui is the empty exoskeleton (the slough) that a cicada nymph sheds as it emerges; the animal itself flies away and is not part of the medicine. Our own record specifies both the range and the part used. Because the material is extremely light for its volume, a 3–9 g dose is a surprisingly large heap of shells.

  • 3–9 g in decoction — the standard range recorded here.
  • Part used — the slough shed by the cicada nymph; the shells are washed of soil and debris before use, and studies show that pre-moulting washing measurably affects the finished material’s composition and activity (PMID 36431784, PMC 9699411).

  Source: our own herb record (dose range and part used); washing/processing effect per PMID 36431784, PMC 9699411. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Chan Tui? Is it safe in pregnancy?

  Chan Tui is contraindicated during pregnancy and in exterior deficiency patterns. Those are the two cautions carried in our own record. The pregnancy contraindication is a classical one, traditionally connected to the herb’s rash-venting, outward-moving character. “Exterior deficiency” means someone who already sweats easily and has a weak surface — a herb whose job is to open and release the exterior is the wrong direction for them.

  • Pregnancy — contraindicated, per the classical caution recorded here.
  • Exterior deficiency — contraindicated; spontaneous sweating and a weak surface are the presentation to avoid.
  • Animal-derived (reference note) — an insect product, unsuitable for vegans and most vegetarians; chitin-based, so worth noting for anyone with a known chitin or shellfish sensitivity. See the identity note above.
  • Immune activity — laboratory work reports immunosuppressive effects on dendritic cells and on contact hypersensitivity responses (PMID 39270880) and regulation of Th1/Th17 differentiation (PMID 32721777); this is preclinical, but it is a reasonable prompt for practitioner awareness in anyone on immunosuppressive therapy.

  Source: our own herb record (pregnancy and exterior-deficiency contraindications); immune findings per PMID 39270880 and PMID 32721777. Neutral reference safety information, not medical advice.

Chinese Herb Toxicity & Overdose

• Chan Tui is not classed as a toxic herb, and no significant toxicity is recorded at customary doses. It is a chitinous, largely inert shell with a long history of use, and it is not on the toxic or endangered list. The realistic concerns are not intrinsic toxicity but material quality — how thoroughly the sloughs were cleaned of soil and debris before processing, which has been shown to alter the finished material’s composition and measured activity — and species substitution in the marketplace.

  Source: our own herb record; processing and species-consistency findings per PMID 36431784, PMC 9699411 and PMID 31767224. Reference note, not a safety guarantee.

Herb-Drug Interactions

• Does Chan Tui interact with medications?

  No well-established clinical herb–drug interactions are documented for Chan Tui. Two preclinical signals are worth a practitioner’s awareness rather than alarm: laboratory studies report immune-modulating and immunosuppressive activity (dendritic cells, contact hypersensitivity, Th1/Th17 differentiation), which suggests care alongside immunosuppressant therapy; and an animal study of sleep-related neurotransmitters suggests theoretical additive effects with sedative medication. Both are precautionary extrapolations from animal and cell work, not demonstrated clinical interactions.

  Source: immune findings PMID 39270880, PMID 32721777; sleep-related neurotransmitter findings PMID 39125043, PMC 11314497. Flagged for practitioner confirmation.

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Chan Tui (Periostracum Cicadae)?

  Yes — an active chemistry and preclinical literature, built around one distinctive compound class: N-acetyldopamine (NAD) polymers. Chemical profiling has identified 34 such compounds across the traded origins of Cicadae Periostracum, including dimers, trimers, tetramers and pentamers, and these are treated as the material’s characteristic markers. The bulk material itself is chitin. All findings below are laboratory or animal work; there is no meaningful human clinical evidence.

  • Characteristic chemistry — 34 N-acetyldopamine polymers profiled across four traded origins (PMID 31767224); new enantiomeric NAD trimers with resolved absolute configurations (PMID 37379971); the cryptamides, four pairs of dopamine enantiomer trimers (PMID 36235243, PMC 9571589); NAD tetrapolymers (PMID 22248067); rat pharmacokinetics of the NAD oligomers (PMID 37348161).
  • Immune and anti-allergic — NAD derivatives regulated Th1 and Th17 cell differentiation (PMID 32721777); extract showed immunosuppressive effects on dendritic cells and contact hypersensitivity (PMID 39270880); an extract of the cicada species reduced ovalbumin-induced allergic airway inflammation in asthmatic mice via Th2/GATA-3 and IL-17/RORγt pathways (PMID 33806085, PMC 8037444). These map onto the traditional antiallergic and rash-venting reputation.
  • Kidney — effects on cytokines and apoptosis-regulatory proteins in an IgA nephropathy rat model (PMID 29844269, PMC 6032130).
  • Neurological and sedative — extract and N-acetyldopamine altered sleep-related neurotransmitters in an insomnia rat model (PMID 39125043, PMC 11314497); the cast-off skin protected dopaminergic neurons in a Parkinson’s disease model (PMID 31772707, PMC 6854990). These are the modern counterpart to the classical sedative and anticonvulsive uses.
  • Skin — extract inhibited oxidative stress and inflammation from UVB irradiation in cultured keratinocytes (PMID 28465707, PMC 5390570).
  • Materials — chitosan derived from the shells has been used to build silver-nanoparticle-loaded hydrogels for haemostasis and wound healing (PMID 40383563) — not a traditional use, but it confirms the chitin basis of the material.

  None of this is clinical proof in people and none of it should be read as a therapeutic claim for the traditional herb.

  Sources: PMID 31767224; PMID 37379971; PMID 36235243, PMC 9571589; PMID 22248067; PMID 37348161; PMID 32721777; PMID 39270880; PMID 33806085, PMC 8037444; PMID 29844269, PMC 6032130; PMID 39125043, PMC 11314497; PMID 31772707, PMC 6854990; PMID 28465707, PMC 5390570; PMID 40383563; PMID 36431784, PMC 9699411. Research context, not a therapeutic claim.

Chinese Herb Notes

• Is Chan Tui made from cicadas? Is it vegetarian or vegan?

  Chan Tui is animal-derived, and it is not vegetarian or vegan — but no cicada is killed for it. The medicine is the discarded exoskeleton the nymph leaves behind on a tree trunk when it moults; the insect itself is not the drug. That distinction matters to many readers, because it puts Chan Tui in an unusual category: an animal product obtained without harming the animal, comparable to a shed feather or a shed skin. It remains an insect-derived material, so it is excluded by vegan and by most vegetarian practice, and it is chitin-based — relevant to anyone with a known shellfish or chitin sensitivity, since chitin is the same structural polymer found in crustacean shells.

  • What it is — the moulted shell (slough) of the cicada nymph; hollow, translucent, brittle, and very light.
  • What it is not — not the cicada’s body, not a whole insect, and not a preparation involving killing the animal.
  • Material — principally chitin, which researchers have converted into chitosan for laboratory materials work (PMID 40383563), alongside the N-acetyldopamine polymers that carry most of its studied activity.

  Which cicada species is Chan Tui?

  The official source is a single species, but the market carries several. The Chinese Pharmacopoeia specifies Cryptotympana atrata as the only official species for Cicadae Periostracum. A chemical-profiling study found that sloughs of Auritibicen flammatus and Cryptotympana mandrina are also traded and have consistent chemical profiles with the official species, while Platypleura kaempferi differed enough to require further evaluation before being accepted as a source.

  Naming note: parts of the research literature give the source species as Cryptotympana pustulata Fabricius rather than Cryptotympana atrata. We believe this reflects synonymous and historically variable insect nomenclature for the same medicinal material rather than a different substance, but the two names do appear side by side in the published literature, so we record both rather than silently choosing one. Our own entry names the material only at the pharmaceutical level (Periostracum Cicadae) and is left unchanged.

  Source: our own herb record (part used); official and market species per PMID 31767224; species naming as it appears in PMID 29844269, PMC 6032130 and PMID 33806085, PMC 8037444; chitin/chitosan material per PMID 40383563. Cross-referenced against multiple online sources.