Chen Pi
StarCitrus reticulata Blanco
☯ TCM Properties
Regulates Qi and strengthens the Spleen; Dries Dampness and Transforms Phlegm; Harmonizes the Middle Burner; Directs Rebellious Qi Downward and Stops Vomiting
Traditional Chinese Uses
Chen Pi (aged tangerine peel) is among the most versatile and commonly used herbs in Chinese medicine. As the aged peel of the mandarin orange, it regulates Qi and transforms Phlegm — easing bloating, nausea, belching, and poor appetite while also supporting expectoration in coughs with Phlegm. Its gentle nature and synergistic quality make it a standard addition to many formulas, where it enhances other herbs' actions and protects the Stomach. The longer it has been aged, the more refined its action is considered.
Western Herbalism Properties
Used In Formulas (6)
Botanical Description
Citrus reticulata is a small evergreen tree in the Rutaceae, thought to have originated in southern China and northeastern India and now cultivated throughout the tropics and subtropics as the mandarin orange and its many cultivars. Trees typically reach 3-8 m tall, with slender, often slightly thorny branches forming a rounded, open crown. The alternate, leathery leaves are lanceolate to elliptic, 4-8 cm long, glossy dark green, and have narrowly winged petioles and gland-dotted blades that release a citrus scent when crushed. Fragrant white flowers, 1.5-2.5 cm across with five waxy petals and many stamens, are borne singly or in small axillary clusters. The fruit is a depressed-globose hesperidium 4-8 cm wide with a loose, easily peeled orange rind, sweet juicy segments and few seeds. The species thrives in warm, frost-free climates on well-drained loamy soils with regular rainfall.
Active Constituents
Hesperidin
Flavanone glycosideConcentration: Predominant flavonoid; Chinese Pharmacopoeia requires not less than 3.5% (dried aged peel)
The principal marker constituent of Chen Pi. Hesperidin shows anti-inflammatory, antioxidant and vasoprotective (capillary-strengthening) activity and contributes to the herb's digestive and phlegm-transforming actions. It is largely hydrolyzed by gut microbiota to the aglycone hesperetin before absorption.
Nobiletin
Polymethoxylated flavoneConcentration: Minor but characteristic (typically <0.3%)
A lipophilic polymethoxyflavone concentrated in citrus peel. Exhibits potent anti-inflammatory, anti-tumor and cardioprotective effects, including protection against pressure-overload cardiac hypertrophy via inhibition of NADPH oxidases and endoplasmic reticulum stress.
Tangeretin
Polymethoxylated flavoneConcentration: Minor characteristic constituent
Together with nobiletin and hesperidin it is considered largely responsible for the anti-neuroinflammatory capacity of tangerine peel. Shows antioxidant, anti-proliferative and neuroprotective activity in preclinical models.
Narirutin
Flavanone glycosideConcentration: Secondary flavonoid glycoside
A companion flavanone glycoside to hesperidin contributing to the total flavonoid pool and antioxidant capacity of the peel.
D-Limonene
Monoterpene (volatile oil)Concentration: Dominant component of the essential oil (often >50% of volatile oil)
The main aromatic volatile responsible for the characteristic odor. Promotes gastrointestinal motility and secretion of digestive juices, supporting the traditional actions of regulating Qi and harmonizing the middle burner; also carminative and mildly choleretic.
Synephrine
Protoalkaloid (phenethylamine)Concentration: Trace
A minor adrenergic amine present in citrus tissues that may contribute mild sympathomimetic and gastrointestinal-stimulating effects.
β-Myrcene
Monoterpene (volatile oil)Concentration: Minor volatile oil component
Contributes to the aromatic profile of the essential oil with reported anti-inflammatory and analgesic activity in preclinical studies.
⚠ Drug Interactions
CYP3A4 substrates (e.g., felodipine, statins, ciclosporin)
Polymethoxyflavones (nobiletin, tangeretin) and flavanones in citrus peel can inhibit intestinal CYP3A4 and P-glycoprotein in vitro, theoretically raising plasma levels of some co-administered substrates. Clinical relevance at culinary/decoction doses is unproven and appears far weaker than grapefruit juice.
Clinical note: No documented clinical events at typical decoction doses; monitor if used long-term with narrow-therapeutic-index CYP3A4 substrates.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3-9g | Daily | — | — | — |
Preparation Methods
Raw aged peel (Chen Pi) decoction
Parts: dried mature pericarp
The mature fruit peel is sun-dried and aged (the name Chen Pi literally means 'aged peel'; well-aged Guang Chen Pi from Citrus reticulata 'Chachi' is prized). Typical dose 3-10 g in water decoction to regulate Qi, strengthen the Spleen and dry Dampness. Because much of the activity resides in volatile oil, it is not overcooked.
Stir-fried peel (Chao Chen Pi)
Parts: dried mature pericarp
Gentle dry stir-frying warms the herb and moderates its dispersing, drying nature, making it gentler on the Spleen and Stomach for patients with weakness of the middle burner.
Clinical Studies
Phytochemistry, pharmacological properties and pharmacokinetics of Citri Reticulatae Pericarpium: A systematic review
Comprehensive systematic review collating the phytochemistry, pharmacology and pharmacokinetics of Chen Pi. It confirms flavonoids (hesperidin, nobiletin, tangeretin) and volatile oils as the principal bioactive classes and summarizes digestive, anti-inflammatory, antioxidant, hepatoprotective and cardiovascular activities.
Historical Texts
Shennong Bencao Jing (Divine Husbandman's Classic of Materia Medica)
Han dynasty (c. 200 CE)Bencao Gangmu (Compendium of Materia Medica), Li Shizhen
Ming dynasty (1578)References
- Zhang X, Jiang Y, Zeng J, Li X, Xie H, Yang R, Qi H, Zeng N. Phytochemistry, pharmacological properties and pharmacokinetics of Citri Reticulatae Pericarpium: A systematic review . Journal of Ethnopharmacology (2024) [DOI]
- Chinese Pharmacopoeia Commission. Pharmacopoeia of the People's Republic of China (2020 Edition), Volume I — Chen Pi (Citri Reticulatae Pericarpium) . China Medical Science Press (2020) [DOI]
- Bensky D, Clavey S, Stöger E. Chinese Herbal Medicine: Materia Medica, 3rd Edition . Eastland Press, Seattle (2004) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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