Traditionally used for
- Nose & throat
- Cough & breathing
- Skin
Cautions & contraindications
- Allergy risk
☯ TCM Properties
Nourishes Yin and cleanses the Lungs
Traditional Chinese Uses
Feng Huang Yi is the thin inner membrane of the hen's eggshell (Gallus gallus domesticus; Membrana Follicularis Ovi), a sweet substance entering the Lung channel. It nourishes Yin and clears the Lungs, moistening dryness of the respiratory tract, and is used chiefly for chronic and lingering dry cough and for Lung Yin deficiency with a dry, scratchy throat. A characteristic traditional application is hoarseness and loss of voice (aphonia), where it soothes and moistens the throat.
It is also applied to scrofula and, topically, to non-healing sores and ulcers, the powder being sprinkled on the affected area. Internally it is decocted at about 3-9 g or taken as powder. A gentle, food-grade animal substance, it is typically used as an adjunct within moistening, Yin-nourishing formulas under professional guidance.
Relationships
Full-screen graph →Click a node for details · double-click to expand it · Ctrl/⌘ + scroll or two fingers to zoom and pan.
Botanical Description
Feng Huang Yi (凤凰衣) is most commonly recorded in Chinese materia medica not as a plant at all but as the thin inner membrane of the hen's eggshell (the chorioallantoic membrane peeled from the inside of a chicken egg after the contents are removed), used as a folk remedy for chronic cough and to promote healing of ulcerations. Some regional sources apply the same name to flower-bract structures of certain ornamental plants, but without a corroborating Latin name the identification cannot be made with confidence. Because the substance is most likely an animal-derived material rather than a plant — and possibly not in standard pharmacopoeial use — the record follows the unidentifiable/non-plant null-pattern.
Active Constituents
Type I collagen
Fibrillar structural protein (collagen)Concentration: The dominant protein of the membrane; the fibre network is predominantly type I collagen with types V and X also reported
Forms the interwoven fibre scaffold that gives the membrane its structure. Its hydroxyproline-rich composition is what distinguishes the shell membranes from the organic matter of the shell itself in amino acid analysis, and it is the basis of the material's use as a wound and ulcer dressing.
Type X collagen
Network-forming (non-fibrillar) collagenConcentration: Present in significant quantity alongside type I
A short-chain network collagen normally associated with hypertrophic cartilage. Its presence is part of the rationale for testing eggshell membrane in joint and connective tissue disorders.
Glycosaminoglycans (hyaluronic acid and a chondroitin sulfate-dermatan sulfate copolymer)
GlycosaminoglycanConcentration: Two glycosaminoglycans are documented in the membrane; uronic acid, their structural marker, occurs at similar levels in inner and outer shell membranes and about fivefold lower than in the organic matter of the shell
These are the constituents that the joint-health supplement literature is built around, being the same classes used as standalone osteoarthritis supplements. In the membrane they are present as native, unstandardised amounts, not as a measured dose.
Sialic acid (N-acetylneuraminic acid)
Amino sugar (nonulosonic acid)Concentration: Higher in the inner shell membrane than the outer, and highest of all in the organic matter of the shell
A terminal sugar on the membrane glycoproteins. Its uneven distribution between inner membrane, outer membrane and shell organic matter means that how carefully the membrane is separated from adherent shell changes the composition of the finished drug.
Desmosine and isodesmosine
Crosslinking amino acids (tetrafunctional lysine-derived)Concentration: About 28 micrograms per 100 mg dry weight of membrane
These crosslinks give the membrane its elastic, tear-resistant character. They are constituents of the shell membrane protein itself and do not indicate contamination with elastin, which was established by specific enzymatic and chemical hydrolysis.
Ovalbumin, ovotransferrin and lysozyme
Egg white proteins (major egg allergens)Concentration: Inherent and abundant residues of egg white carried on the membrane; not removed by ordinary drying
These are the clinically important constituents of Feng Huang Yi, because they are the named major egg allergens: ovalbumin is Gal d 2, ovotransferrin is Gal d 3 and lysozyme is Gal d 4. Proteomic work on eggshell membrane identifies them directly, along with ovoinhibitor, ovostatin and ovalbumin-related protein X. Their presence means the drug is an egg product for allergy purposes, whatever the preparation.
Cystine-rich shell membrane proteins
Disulfide-crosslinked structural proteinConcentration: Cystine is a prominent component of the membrane amino acid profile
The disulfide crosslinking makes the membrane poorly soluble and resistant to digestion, which is why commercial preparations are hydrolysed enzymatically or with subcritical water rather than used whole.
⚠ Drug Interactions
Any therapy in a patient with egg allergy, including egg-cultured vaccines and egg-derived lysozyme preparations
Feng Huang Yi is the membrane lining a chicken eggshell, and proteomic analysis of eggshell membrane identifies ovalbumin, ovotransferrin and lysozyme among its proteins — these are Gal d 2, Gal d 3 and Gal d 4, three of the four principal egg white allergens, and together they account for the large majority of egg white allergenic protein. The drug is therefore an egg protein exposure. There is no published assay of residual allergen in medicinal eggshell membrane to say how much survives decoction, so the exposure cannot be quantified, but absence of an assay is not evidence of absence. In a patient already sensitised, this adds an allergen source alongside any other egg-derived exposure they are managing.
Clinical note: Contraindicated in known egg allergy. Ask about egg allergy before prescribing, including in children, and record the herb as an egg-containing product so that it is visible to other clinicians assessing an allergic reaction. If a patient on Feng Huang Yi develops urticaria, angioedema, wheeze or gastrointestinal symptoms, stop it and treat as an egg reaction.
Glucosamine and chondroitin sulfate joint supplements
Eggshell membrane contains hyaluronic acid and a chondroitin sulfate-dermatan sulfate copolymer natively, and the commercial supplements built on it are marketed for the same indication as glucosamine and chondroitin. Taking both duplicates the same class of material at an unmeasured combined dose. No adverse interaction has been reported; the concern is cost and unmonitored intake rather than toxicity.
Clinical note: No action beyond noting the duplication. Do not treat the TCM decoction as interchangeable with a standardised eggshell membrane supplement — the doses and preparations are not comparable.
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Disperses wind-heat and benefits the throat while nourishing and restoring the voice, for hoarseness and loss of voice.
Named pairing — Lü Jingshan, Shi Jinmo Dui Yao
Evidence Tier
Moderate evidence · 3 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
2
2 verified · 0 unverified
Show 2 studies
- Eggshell membrane in the treatment of pain and stiffness from osteoarthritis of the knee: a randomized, multicenter, double-blind, placebo-controlled clinical study
- A Randomized, Double-Blind, Placebo-Controlled, Prospective Clinical Trial Evaluating Water-Soluble Chicken Eggshell Membrane for Improvement in Joint Health in Adults with Knee Osteoarthritis
Other clinical trial
1
1 verified · 0 unverified
Observational / case report
0
In vitro / animal
0
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Eggshell membrane in the treatment of pain and stiffness from osteoarthritis of the knee: a randomized, multicenter, double-blind, placebo-controlled clinical study
Sixty-seven patients with knee osteoarthritis randomised to 500 mg/day of a proprietary Natural Eggshell Membrane preparation or placebo for eight weeks, with WOMAC pain and stiffness as the primary endpoint. This is the strongest human evidence for the material, but two qualifications matter for a TCM reference: the indication tested is knee osteoarthritis, not the Lung and Yin-nourishing indications Feng Huang Yi is prescribed for, and the corresponding author is affiliated with ESM Technologies LLC, the manufacturer of the tested product.
A Randomized, Double-Blind, Placebo-Controlled, Prospective Clinical Trial Evaluating Water-Soluble Chicken Eggshell Membrane for Improvement in Joint Health in Adults with Knee Osteoarthritis
Eighty-eight adults with knee osteoarthritis randomised to 450 mg/day of a water-soluble chicken eggshell membrane hydrolysate or placebo for 12 weeks. The honest reading is negative on the pre-specified analysis: without normalisation, no statistically significant improvement was seen in WOMAC, six-minute walk test or range of motion, and the positive findings the paper reports come from a normalised improvement-over-baseline analysis. The product was safe. Two authors received funding from the sponsor and a third is a paid consultant to it.
Eggshell membrane: A possible new natural therapeutic for joint and connective tissue disorders. Results from two open-label human clinical studies
Two small single-centre open-label studies, 11 and 28 patients, given 500 mg/day of Natural Eggshell Membrane for four weeks, reporting reductions in joint pain and gains in flexibility with no adverse events. Uncontrolled and unblinded, so the effect sizes cannot be separated from placebo and regression to the mean; the useful content is the tolerability signal. The corresponding author is employed by the product manufacturer.
Historical Texts
Ming Yi Bie Lu (Miscellaneous Records of Famous Physicians), entered as luan zhong bai pi, the white skin within the egg
attributed to Tao Hongjing, c. 500 CEBi Xiao Fang (Formulas of Certain Efficacy), Meng Shen, cited under the name ji zi bai pi
Tang dynasty, 7th-8th centuryBen Cao Meng Quan (Enlightenment of Materia Medica), Chen Jiamo
Ming dynasty, 1565References
- Nakano, T; Ikawa, N I; Ozimek, L. Chemical composition of chicken eggshell and shell membranes . Poultry Science (2003) [DOI]
- Ahlborn, G. J.; Clare, D. A.; Sheldon, B. W.; Kelly, R. W.. Identification of Eggshell Membrane Proteins and Purification of Ovotransferrin and β-NAGase from Hen Egg White . The Protein Journal (2006) [DOI]
- Leach, R. M.; Rucker, R. B.; Van Dyke, G. P.. Egg shell membrane protein: A nonelastin desmosine/ isodesmosine-containing protein . Archives of Biochemistry and Biophysics (1981) [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.
📝 Notes
Public notes from the community and your own private notes on Feng Huang Yi.
No notes yet.