Periostracu Cicadae (Chan Tui)

Periostracum Cicadae (chan tui, 蝉蜕), also known as Cicada Slough, is the cast-off shell of Cryptotympana pustulata Fabricius after eclosion, which is a hemi-winged insect belonging to the family Cicada. These insects usually inhabit grasslands and forests, and survive by sucking the sap from the roots of plants. After staying in the soil for several years, these insects will climb up the trunk of and grasp the bark of trees during eclosion to finish molting. These molted skins look like yellow-brown flower petals. 

In ancient China, Cicada is a symbol for immortality and a religious symbol for reincarnation, as it demonstrates the process of leaving one’s ‘old’ life behind and starting anew. The insect itself is only used as a food, deep-fried and eaten without its outer skin.

In summer and autumn every year, people will gather the cast-off shells of Cryptotympana pustulata Fabricius after eclosion, remove impurities and dry them under the sun for medicinal usage.

In Traditional Chinese Medicine (TCM), Periostracum Cicadae falls under the category of ‘Cool/Acrid herbs that release the Exterior’. Such herbs can treat the early stages of diseases that affect the upper respiratory tract, the eyes, the ears, the nose, the throat or the skin. It is believed that these herbs can induce sweating by dilating our capillary pores to expel external diseases from the body and prevent it from invading further.

Cold in nature, Periostracum Cicadae can help individuals with too much Heat in their body, such as those experiencing a Yang Excess or a Yin Deficiency, to restore a harmonious yin-yang balance in the body. Bitter and salty in taste, Periostracum Cicadae can cleanse the body by clearing Heat, drying Dampness and promoting elimination via urination or bowel movements. Also, the herb has a draining effect on the body by clearing accumulations, removing phlegm and softening hard lumps. In particular, Periostracum Cicadae targets the Liver and the Lungs.

Traditional Chinese Medicine (TCM) shows that Periostracum Cicadae has the following health benefits.

Periostracum Cicadae can disperse Wind-Heat and expel pathogens to release the exterior. The herb can be used together with other Wind-Heat-dispersing herbs such as chrysanthemum to treat exterior syndromes and warm diseases manifested as symptoms such as fever and headache, and especially a loss of voice. As Periostracum Cicadae is efficient in ventilating the Lungs and relieving sore throat, it is also often used in conjunction with other exterior-releasing herbs and sore-throat relieving herbs to treat the stagnation of Wind-Heat in the Lungs with symptoms such as hoarse voice, itching and cough.

Periostracum Cicadae can vent rashes and relieve itching. It can promote eruption of early stage measles with incomplete expression of the rashes. To treat inadequate eruption due to Wind-Heat, you can combine Periostracum Cicadae with other exterior-releasing or eruption-promoting herbs to enhance its effectiveness.

As Periostracum Cicadae can clear Liver-Heat, it can help to improve vision and address blood-shot eyes with nebula. The herb is often used in conjunction with Liver-Heat-clearing or eyesight-improving herbs to treat blood-shot eyes with lacrimation and nebula. Other eye problems caused by Wind-Heat that Periostracum Cicadae can address include red, painful swollen eyes, blurry vision and eye twitching .

Also, as Periostracum Cicadae can subdue Liver-Wind, it can relieve spasms, and can be indicated for syndromes of the stirring of Liver Wind, such as childhood fevers, chronic or acute infantile convulsions, delirium, spasms, terror, tetanus, insomnia and nightmares.

Modern research has suggested that Periostracum Cicadae may be effective in treating the morbid crying of infants during night time as the herb can soothe one’s spirit.

Periostracum Cicadae can be found in herbal stores and Asian specialty markets.

The recommended daily dosage of Periostracum Cicadae is 6 – 15g, when the herb is pounded and taken as an infusion. While small doses are usually used, large doses should be indicated for convulsions.

Periostracum Cicadae should not be used by individuals who are experiencing pregnancy or Exterior Deficiency. Also, the herb has a sedative effect, and hence may potentiate the effect of other sedatives and reduce the effect of caffeine.

Over-consuming Periostracum Cicadae may cause side effects such as abdominal pain and fatigue.

We strongly encourage you to consult your healthcare provider before deciding to add Periostracum Cicadae to your healthcare routine.

Here is a summary for Periostracu Cicadae (Chan Tui):

• Herb name (Chinese): 蝉蜕
• Herb name (Pin Yin): chán tuì
• Herb name (English): Cicada Slough
• Herb name (Botanical): Periostracum Cicadae
• Origin of species: Cryptotympana pustulata Fabricus
• Part(s) of herb used: Slough of the nymph
• Geo-specific habitat(s): Shandong, Hebei, Henan, Jiangsu
• Taste(s) & Properties: Sweet; Cold; Administrates the Lung and Liver Meridians
• Actions: Eases early or mild symptoms of respiratory ailments; Relieves skin rashes, and eye and throat discomforts; Aids to relieve symptoms of spasm

Hsieh, M. T., Peng, W. H., Yeh, F. T., Tsai, H. Y., & Chang, Y. S. (1991). Studies on the anticonvulsive, sedative and hypothermic effects of Periostracum Cicadae extracts. Journal of ethnopharmacology, 35(1), 83-90. [Accessed on 8th February 2023]

Xu, M. Z., Lee, W. S., Han, J. M., Oh, H. W., Park, D. S., Tian, G. R., … & Park, H. Y. (2006). Antioxidant and anti-inflammatory activities of N-acetyldopamine dimers from Periostracum Cicadae. Bioorganic & medicinal chemistry, 14(23), 7826-7834.[Accessed on 8th February 2023]