Fu Ling Pi
StarPoria cocos (Schw.) Wolf
Traditionally used for
- Cough & breathing
- Urinary & fluids
- Mood & calm
- Skin
Cautions & contraindications
- Heart conditions
☯ TCM Properties
Promotes Urination and Reduces Edema; Drains Water from the Skin and Flesh; Opens the Water Pathways
Traditional Chinese Uses
Fu Ling Pi (茯苓皮), Cortex Poriae Cocos, is the dark outer skin peeled from the sclerotium of the fungus Poria cocos (Schw.) Wolf. It is sweet and bland and neutral, entering the Lung, Spleen and Kidney channels. It promotes urination and reduces oedema, drains Water from the skin and flesh, and opens the water pathways.
Where Fu Ling itself both drains Dampness and strengthens the Spleen and calms the Spirit, the skin does one thing and does it more strongly: it moves water. It is chosen specifically for superficial oedema — puffiness of the face, eyelids and limbs, and swelling held in the skin and flesh — the pattern of skin oedema (皮水), and it heads Wu Pi San, the five-peel decoction, with the peels of ginger, mulberry root, tangerine and areca.
It is bland and gentle and does not readily damage the Qi, but as a draining herb it is used with care where fluids are already depleted or urination is copious.
Western Herbalism Properties
Relationships
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Botanical Description
Poria cocos (now Wolfiporia extensa or W. cocos) is a wood-decay fungus in the Polyporaceae family that forms large, irregular, subterranean sclerotia attached to the roots of pines, especially Pinus massoniana and other species. The sclerotium is a hard, dense, tuber-like body 10-30 cm or more across, with a thin, wrinkled, dark brown to blackish outer rind and an interior of solid, fine-grained, white to pale pink flesh composed of densely packed hyphae embedded in polysaccharide matrix. Aerial fruiting bodies are rarely seen in cultivation, and the medicinal trade focuses entirely on the sclerotium. Fu Ling Pi specifically denotes the dried outer rind or peel pared off the sclerotium, a thin, brown, papery to leathery strip (Wikipedia; POWO).
Active Constituents
Poricoic acid A
3,4-seco-lanostane tetracyclic triterpene acidConcentration: One of the two dominant triterpene acids of the sclerotial skin; purified to 92 percent from Poriae cutis by counter-current chromatography
A skin-enriched triterpene rather than a whole-sclerotium one. Isolated in quantity from the epidermis, it induces apoptosis and G2/M arrest in HepG2 cells in vitro through PI3K/AKT, MAPK and p53 signalling, and a related preparation attenuates renal fibrosis by suppressing endoplasmic-reticulum-stress-mediated apoptosis in rodents. It is a marker of the peel, not of the peeled sclerotium.
Poricoic acid B
3,4-seco-lanostane tetracyclic triterpene acidConcentration: The other dominant triterpene acid of the skin; purified to 90 percent from Poriae cutis
The most active anti-inflammatory triterpene identified in the peel: in lipopolysaccharide-stimulated RAW 264.7 macrophages it suppressed nitric oxide production more strongly than poricoic acid A and reduced tumour necrosis factor alpha, interleukin 1 beta and interleukin 6 dose-dependently from 10 to 40 micrograms per millilitre.
Dehydrotrametenolic acid
Lanostane tetracyclic triterpene acidConcentration: Present in the skin at 93 percent purity after isolation; also present in the inner sclerotium
Isolated from the peel alongside the poricoic acids but, unlike poricoic acid B, showed no anti-inflammatory activity in the same macrophage assay. It is included so that total triterpene content is not read as though every triterpene were active.
Dehydroeburicoic acid
Lanostane tetracyclic triterpene acidConcentration: Isolated from Poriae cutis at 96 percent purity
A lanostane triterpene of the peel that, like dehydrotrametenolic acid, was inactive in the macrophage nitric oxide assay in which poricoic acid B was active.
Poricolides A and B
Tetranorlanostane triterpenoids with a delta-lactone ring at C-17Concentration: Trace new compounds isolated specifically from the epidermis
Two previously unreported triterpenoid skeletons described from the epidermis of Poria cocos, the first tetranorlanostanes bearing a delta-lactone at C-17. With two co-isolated lanostanes they were antiproliferative against A549, SMMC-7721, MCF-7 and SW480 cell lines with IC50 values of roughly 16 to 28 micromolar. Preclinical chemistry only; no clinical relevance is established.
Pachymic acid
Lanostane tetracyclic triterpene acidConcentration: Present in the skin and in the inner sclerotium; Chinese analytical work reports total triterpene acids in the peel roughly an order of magnitude above white Poria
The best-studied Poria triterpene and one of the stable index compounds used for content determination. It is shared with the peeled sclerotium, so it is not what distinguishes this drug; what distinguishes the peel is how much triterpene acid it carries relative to the inner tissue.
Beta-(1 to 3)-D-glucan
Fungal cell-wall polysaccharideConcentration: Relative molecular mass distribution about 9.13 times 10 to the fourth to 1.04 times 10 to the fifth, essentially the same as in white Poria
Recorded here as a negative finding that matters for dosing. Comparative gel-permeation and NMR work on alkali-soluble polysaccharides found that the skin, red Poria and white Poria all yield beta-(1 to 3)-D-glucans of closely similar composition and molecular mass. The polysaccharide fraction therefore does not distinguish this drug from Fu Ling; only the triterpene acid fraction does.
Ethyl acetate soluble fraction of the ethanol extract
Mixed fraction of intermediate-polarity lanostane triterpenoidsConcentration: Active in rats at 25 to 50 milligrams per kilogram by mouth
The fraction of the peel that carries its diuretic activity. In saline-loaded rats it raised urine output over six hours and increased sodium and chloride excretion while leaving potassium excretion unchanged, so the sodium to potassium ratio rose: a potassium-sparing pattern of natriuresis. The n-butanol fraction was also diuretic but did not raise the sodium to potassium ratio, and the petroleum ether and residual fractions were inactive.
⚠ Drug Interactions
Fu Ling, Fu Shen and Chi Fu Ling (other parts of the same sclerotium)
All four drugs come from one sclerotium of the same fungus: this drug is the outer skin, Fu Ling the peeled inner flesh, Chi Fu Ling the reddish layer beneath the skin, and Fu Shen the portion enclosing the pine root. They are not interchangeable by weight. Chinese analytical work ranks total triterpene acid content peel above red Poria above white Poria above Poria with pine root, with the peel carrying roughly ten times the tetracyclic triterpene content of white Poria and a wider range of individual triterpenes; comparative HPLC-QTOF work counted 31 triterpene acids in the epidermis against 24 in the inner sclerotium. The polysaccharide fraction, by contrast, is nearly identical across the parts. Substituting one part for another therefore changes the triterpene dose substantially while leaving the glucan dose about the same.
Clinical note: Specify the part when prescribing and when purchasing, and do not convert a dose given for Fu Ling into the same weight of this drug. Because supplier labelling often reads only Poria or Fu Ling, confirm which part has actually been supplied.
Loop and thiazide diuretics
The diuretic effect of this drug is not folklore: the ethyl acetate and n-butanol fractions of the ethanol extract produced a marked increase in urine output and in sodium and chloride excretion in saline-loaded rats. The effect is potassium-sparing in pattern, so additive potassium loss is not expected, but additive sodium and water loss is. The evidence is animal only, with no human pharmacodynamic study, so the size of any clinical effect is unknown.
Clinical note: In a patient already on a diuretic for cardiac, hepatic or renal oedema, monitor weight, blood pressure and serum sodium rather than assuming the herb is inert. More importantly, treating oedema with a herbal diuretic without establishing its cause risks delaying diagnosis of heart failure, nephrotic syndrome or cirrhosis.
Lithium
Sodium depletion increases proximal tubular lithium reabsorption and raises serum lithium, which is the mechanism behind the established thiazide-lithium interaction. Since the peel produces natriuresis in animals, the same mechanism is available in principle. No case report or pharmacokinetic study of this combination exists, and it is listed as a mechanism-based caution rather than an observed event.
Clinical note: If a patient on lithium takes this herb, check lithium concentrations rather than relying on the absence of published cases.
CYP3A4 substrates with narrow therapeutic index
Triterpenes of the sclerotial skin were shown to ameliorate metabolic-associated steatotic liver disease in rodents by inhibiting the pregnane X receptor and the NLRP3 inflammasome. The pregnane X receptor is the transcriptional regulator that induces CYP3A4 and P-glycoprotein, so a preparation that inhibits it could in principle reduce induction of those pathways. This has not been tested as a drug interaction in animals or humans, and no clinical case has been reported.
Clinical note: Not a reason to withhold the herb, but if a patient on ciclosporin, tacrolimus, a direct oral anticoagulant or another narrow-index CYP3A4 substrate begins a Poriae cutis preparation, monitor the index drug as you would for any new botanical.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 15–30 g | Daily | — | — | 中国药典 2020 【用法与用量】15~30g。 【性味与归经】甘、淡，平。归肺、脾、肾经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Moderate evidence · 6 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
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
6
2 verified · 4 unverified
Show 6 studies
- Diuretic activity of some fractions of the epidermis of Poria cocos
- Renal metabolic profiling of early renal injury and renoprotective effects of Poria cocos epidermis using UPLC Q-TOF/HSMS/MSE
- Anti-Inflammatory Activity of Four Triterpenoids Isolated from Poriae Cutis
- Regulation of Tumor Apoptosis of Poriae cutis-Derived Lanostane Triterpenes by AKT/PI3K and MAPK Signaling Pathways In Vitro
- Tetranorlanostane and Lanostane Triterpenoids with Cytotoxic Activity from the Epidermis of Poria cocos
- Poriae cutis triterpenes ameliorate metabolic-associated steatotic liver disease by inhibiting PXR/NLRP3 pathways
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
Diuretic activity of some fractions of the epidermis of Poria cocos
The core pharmacological study of this specific part. Petroleum ether, ethyl acetate, n-butanol and residual fractions of an ethanol extract of the epidermis were given orally to saline-loaded rats. All fractions raised urinary excretion, but the ethyl acetate fraction at three doses produced marked six-hour urine output with increased sodium and chloride excretion and no change in potassium excretion, raising the sodium to potassium ratio. The n-butanol fraction was diuretic without that ratio change; petroleum ether and residual fractions were not. The authors attribute the potassium-sparing diuresis to intermediate-polarity lanostane triterpenoids.
Renal metabolic profiling of early renal injury and renoprotective effects of Poria cocos epidermis using UPLC Q-TOF/HSMS/MSE
A metabonomic study of the epidermis in a rodent chronic kidney disease model. Nineteen metabolites separated diseased from control animals; ten of them, including indoxyl sulfate, p-cresol sulfate, hippuric acid, allantoin and several lysophospholipids, returned toward control values after treatment with the epidermis extract, implicating fatty acid, phospholipid, purine and tryptophan metabolism. This is a biomarker study in animals and does not demonstrate clinical renal benefit.
Anti-Inflammatory Activity of Four Triterpenoids Isolated from Poriae Cutis
Poricoic acid B, poricoic acid A, dehydrotrametenolic acid and dehydroeburicoic acid were separated from Poriae cutis by high-speed counter-current chromatography at 90 to 96 percent purity and tested on lipopolysaccharide-stimulated RAW 264.7 macrophages. Poricoic acid B was the most active, suppressing nitric oxide more than poricoic acid A and reducing tumour necrosis factor alpha, interleukin 1 beta and interleukin 6 dose-dependently between 10 and 40 micrograms per millilitre; the two lanostanes were inactive. A cell-based study with no animal or human data.
Regulation of Tumor Apoptosis of Poriae cutis-Derived Lanostane Triterpenes by AKT/PI3K and MAPK Signaling Pathways In Vitro
Poricoic acids A and B purified from Poriae cutis increased apoptosis and produced G2/M arrest in HepG2 hepatoma cells, generated reactive oxygen species and reduced migration and invasion, with PCR and docking implicating PI3K/AKT, MAPK and p53 signalling and downstream caspases, matrix metalloproteinases and adhesion molecules. Cell-line work only; it supports no clinical claim about cancer.
Tetranorlanostane and Lanostane Triterpenoids with Cytotoxic Activity from the Epidermis of Poria cocos
Phytochemical study of the epidermis specifically. Two unprecedented tetranorlanostane triterpenoids, poricolides A and B, and two new lanostanes were isolated and their structures settled by NMR, high-resolution mass spectrometry and X-ray diffraction. All four were antiproliferative against A549, SMMC-7721, MCF-7 and SW480 cells with IC50 values of about 16 to 28 micromolar. It establishes that the epidermis carries triterpene skeletons not previously described from the drug, at trace level.
Poriae cutis triterpenes ameliorate metabolic-associated steatotic liver disease by inhibiting PXR/NLRP3 pathways
Triterpenes from the sclerotial skin reduced metabolic-associated steatotic liver disease in a rodent model, with the effect attributed to inhibition of pregnane X receptor signalling and the NLRP3 inflammasome. The finding is of interest here less for the liver indication, which is preclinical, than because pregnane X receptor inhibition is the plausible route to a pharmacokinetic interaction with CYP3A4 substrates.
⚠ Safety & Contraindications
- Heart conditions
Contraindications
No special contraindications.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, p. 144.
Historical Texts
Ben Cao Gang Mu, Li Shizhen
Ming dynasty, 1596Wu Pi San (Five Peels Powder), attributed to the Zhong Zang Jing
Text attributed to Hua Tuo of the Eastern Han but of disputed and probably much later datePharmacopoeia of the People's Republic of China
Current editions, including 2020 and 2025Fungal nomenclature for this drug
Twentieth and twenty-first centuriesReferences
- Dong H, Wu P, Yan R, Xu Q, Li H, Zhang F, Li J, Yang B. Enrichment and separation of antitumor triterpene acids from the epidermis of Poria cocos by pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography . Journal of Separation Science (2015) [DOI]
- Yang CX, Wang WW, Feng WH, Liu XQ, Zhang YX, Mao HJ, Wang ZM, Yan LH. Comparative study on composition and content of beta-(1 to 3)-D-glucan in different medicinal parts of Poria cocos . Zhongguo Zhong Yao Za Zhi (China Journal of Chinese Materia Medica) (2026)
- Liu Q, Tang H, Xie P, Huang J, Zuo Y, Wen M. Comparative analysis of volatile organic compounds in different parts of Poria cocos . Frontiers in Chemistry (2026) [DOI]
- Yin M, Yang M, Han X, Yin L, Peng H, Huang L. Spatial metabolic heterogeneity in Poria cocos (Schw.) Wolf (Fushen): Insights from quantitative analysis and widely targeted metabolomics . Food Chemistry: X (2025) [DOI]
- Zhao H, Liu T, Yang CE, Hu YH, Niu Y, Lei SP, Chen L, Zhang MX. Poricoic acid A attenuates renal fibrosis by inhibiting endoplasmic reticulum stress-mediated apoptosis . Brazilian Journal of Medical and Biological Research (2024) [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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