Fu Ling Pi (Poria Skin)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Fu Ling Pi?

  Roughly 15–30 g in decoction — a noticeably larger range than Fu Ling itself, because the peel is a light, bulky material used for its draining effect alone. This reference carries two sourced figures: 10–15 g and 15–30 g, the wider range being the more usual modern practice when edema is the target.

  • Preparation — decocted with the other herbs; no special processing, soaking, or late addition is called for.
  • Choosing between the parts — if the case needs Spleen tonification or calming of the shen alongside the draining, the whole sclerotium (Fu Ling) or the pine-root portion (Fu Shen) is the appropriate choice; Fu Ling Pi is the option when only the water-draining action is wanted.

  Dosage note: the two figures held here (10–15 g and 15–30 g) are both attested in the standard literature and reflect a genuine difference between reference works rather than an error; the higher band is the one most commonly cited for edema.

  Source: this reference’s own dosage record (two cited ranges); cross-referenced against multiple online sources and standard materia medica ranges. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Fu Ling Pi?

  This reference records that it should be used with caution in cases of yin deficiency or spermatorrhea. The reasoning is consistent across the damp-draining category: a herb whose whole action is to move fluid out through the urine can further deplete someone whose fluids are already deficient, or add to a pattern of leakage rather than restraining it.

  • Not a tonic. Because the tonifying part of the fungus has been stripped away, Fu Ling Pi gives none of the Spleen support that softens Fu Ling’s draining action — a relevant consideration in prolonged use or in a depleted patient.
  • Pattern-matched use. Its indication is dampness and edema; it is not appropriate where copious urination already reflects deficiency-cold rather than fluid accumulation.

  Source: this reference’s own cautions record; cross-referenced against multiple online sources and materia medica consensus (Bensky; Chen & Chen). Reference only, not a substitute for practitioner guidance.

Chinese Herb Toxicity & Overdose

• Very low. Poria cocos has a long dual history as both food and medicine in China — the sclerotium is cooked into soups, congees and cakes — and no significant toxicity is reported at standard traditional doses for the fungus or its peel. As with the fungus generally, that reassurance rests mainly on extensive traditional dietary and clinical use rather than on formal toxicology trials; dedicated safety studies remain limited.

  Source: materia medica consensus and the dual food/medicine status of Poria cocos; consistent with the toxicity note held for Fu Ling in this reference. Reference note, not a safety guarantee.

Herb-Drug Interactions

• No well-established clinical herb–drug interactions are documented for Fu Ling Pi. Because its defining action is diuretic — and animal work confirms a real, measurable increase in urine output and sodium excretion — practitioner awareness is reasonable for patients taking prescription diuretics, or medication whose clearance is sensitive to fluid and electrolyte shifts (lithium is the standard example). This is a precautionary inference from its known pharmacology, not a demonstrated clinical interaction. (Flagged for practitioner confirmation.)

  Source: PMID 23058989 and PMID 24184192 (animal diuresis studies on the epidermis of Poria cocos, below). Precautionary note only.

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 Fu Ling Pi (Poria cocos peel)?

  Yes — and unusually for a minor herb, the research is on the peel specifically rather than on the whole fungus, and it supports the traditional claim directly: extracts of the Poria peel increase urine output in animals. The evidence is preclinical (rat studies and chemical analyses), not clinical trial evidence in people.

  • Diuretic activity, rat model (2012) — a Journal of Ethnopharmacology study of the surface layer of Poria cocos, naming it “Fu-Ling-Pi”, found the ethanol extract significantly increased the urinary excretion rate in saline-loaded rats, with a notable increase in sodium excretion but little or no effect on potassium; the water extract produced only a slight, non-significant increase. The authors concluded the diuretic effect belongs to the ethanol rather than the aqueous extract.
  • Which fractions do it (2013) — a follow-up in the same journal separated that ethanol extract into fractions and found the ethyl acetate and n-butanol fractions carried the diuretic activity, raising sodium and chloride excretion while sparing potassium; petroleum ether and residual fractions did not. The authors linked the potassium-sparing pattern to lanostane-type triterpenoids of intermediate polarity.
  • Peel versus whole fungus — a 2025 review in Acta Pharmacologica Sinica on Poria triterpenoids notes that the outer peel layer shows stronger diuretic activity than the whole sclerotium — a modern concordance with the classical decision to separate Fu Ling Pi from Fu Ling for edema.
  • Chemistry of the four parts — a 2019 metabolomics comparison of the four commercial parts of Poria cocos identified 51 triterpene compounds and singled out four (including poricoic acid D) as likely contributors to the diuretic effect; the peel and the pine-root portion separated clearly from each other in the analysis. New lanostane triterpenes have since been isolated from the peel specifically, and peel-derived triterpenes have been studied for apoptosis-related activity in cell lines — laboratory work only.

  Overall: for a herb of this size, the modern evidence is notably well aligned with the traditional indication — but it is animal and chemical evidence for the extract, not clinical proof for the decoction.

  Sources: PMID 23058989 (J Ethnopharmacol 2012;144(3):775-8, DOI 10.1016/j.jep.2012.09.033 — diuretic activity of Poria cocos surface layer in rats); PMID 24184192 (J Ethnopharmacol 2013;150(3):1114-8 — diuretic fractions of the epidermis); PMID 39482471 (Acta Pharmacol Sin 2025 — Poria triterpenoid review, peel/diuresis note); PMID 31108794 (Food Res Int 2019 — triterpene comparison of four botanical parts); PMID 37165599 (Nat Prod Res 2024 — new lanostane triterpenes from the epidermis); PMID 37892435 (Nutrients 2023 — Poriae cutis lanostane triterpenes, in-vitro study). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Fu Ling Pi different from Fu Ling, Fu Shen, and Chi Fu Ling?

  All four are the same fungal body — the sclerotium of Poria cocos, grown on pine roots — separated into layers, and each layer is treated as its own medicine. This reference already holds three of them; the fourth is a recognised grade in the wider literature.

  • Fu Ling Pi (this herb) — the dark outer skin. Promotes urination and reduces edema, and is the choice for skin-level swelling. The most purely draining of the four; it does not tonify.
  • Fu Ling — the pale bulk of the sclerotium with skin and any woody core removed. The general-purpose form: drains dampness, tonifies the Spleen, and calms the Heart/shen all at once, which is why it appears in more formulas here than almost any other herb.
  • Fu Shen — the portion that has grown around and enclosed a pine root. Traditionally regarded as superior to plain Fu Ling for calming the spirit (palpitations, insomnia, forgetfulness), with a correspondingly milder diuretic action.
  • Chi Fu Ling (“red” Poria) — the reddish-tinged layer just under the skin, classically described as draining damp-heat more specifically than the pale inner flesh. It is not currently held as a separate entry in this reference, though it is a standard part-distinction elsewhere and is analysed as one of the four commercial parts in the modern chemical literature.

  A modern echo of the classical split. Laboratory work supports the traditional division rather than flattening it: a chemical comparison of the four commercial parts (outer skin, red layer, white flesh, and the pine-root portion) found the skin and the pine-root portion clearly separable by their triterpene profiles, with several compounds specifically associated with diuretic effect concentrated in the peel — which is exactly the part traditional practice reserves for draining water.

  Formula context: in this reference Fu Ling Pi appears in Wu Pi San (Wu Pi Yin), Five Peel Powder, where it works with Da Fu Pi (betel husk) to leach out dampness through urination, alongside Sang Bai Pi, Chen Pi, and Sheng Jiang Pi. (Traditional formula context, not treatment advice.)

  Naming note: this reference records the pharmaceutical Latin as “Sclerotii Poriae Cocos”, which names the sclerotium but not the part of it actually used; the forms usual in the literature for this herb identify the skin explicitly (for example Poriae Cutis / Cortex Poriae Cocos), and the modern chemical literature indexes it as Poriae Cutis. Left unchanged in the identity field pending owner confirmation; flagged for the data-quality list.

  Source: this reference’s own records for Fu Ling, Fu Ling Pi and Fu Shen, and its Wu Pi San formula record; PMID 31108794 (comparison of triterpene compounds across four botanical parts of Poria cocos); cross-referenced against multiple online sources and materia medica consensus (Bensky; Chen & Chen).