MineralsPhlegm-resolvingPumex

Fu Shi (Pumice)

A practical guide to Fu Shi: what it is, how Traditional Chinese Medicine uses it, the classical formulas it appears in, and who should be careful with it.

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Last reviewed Oct 28, 2026

Quick Facts

Latin Name	Pumex
Chinese Name & Pinyin	浮石 · Fu Shi
Medicinal Part	Minerals
The item	Fu Shi is porous volcanic pumice. Hai Ge Qiao (clam shell) and other rocks are not this drug.
Nature and channels	Cold, salty. Enters the Lung and Kidney. Cold salty clears and transforms heat-phlegm, softens hardness, disperses lumps, and promotes urination.
Pharmacopoeia line	Clears the lung and transforms phlegm; softens hardness and disperses lumps; promotes urination and eases painful urination. Used for lung-heat thick phlegm, cough, neck lumps, and scanty urine.
Pattern cues	Thick yellow phlegm. Sticky throat. Tight chest. Hoarse voice. Neck lumps. Belly gatherings. Scanty urine.
In this article	Fu Shi versus Hai Ge Qiao. Clearing the lung's heat-phlegm versus clearing lung-stomach heat and curbing acid. Why a cold weak spleen-stomach should skip it. Home tea and soup.

What Is Fu Shi?

Fu Shi (浮石; Fú Shí; Latin: Pumex; English: pumice) is the porous light-gray rock formed when volcanic lava meets cold air — not a plant, but the stone itself, washed and dried, kept in old apothecary shops for heat-phlegm stuck in the throat and lumps gathering in the neck. It is cold, salty, enters the Lung and Kidney channels, and its core actions are to clear and transform heat-phlegm, and to soften hardness and disperse lumps. It is the body's quiet "clearance worker" for gathered phlegm. The usual amount is 5–10 g in a decoction. The raw stone is boiled first for 30 minutes; the calcined form boils with the other herbs. It is not swallowed as a powder on its own.

It is not Hai Ge Qiao. Clam shell is cool, salty, and heavy — it clears lung-stomach heat and also curbs excess stomach acid; this pumice is cold and porous — it clears the lung's heat-phlegm and also promotes urination. It is not a tonic; it is a draining stone with no supplementing side. In a cold weak spleen-stomach — usually afraid of cold, pale thin phlegm — or in pregnancy, using it on your own is a poor match. Lumps that are unclear in nature, or growing, need a clinic first. Do not take it yourself for a long time.

It is used most often for three patterns:

Thick yellow sticky phlegm that will not come up, a tight throat, a hoarse voice — lung heat with phlegm
Lumps in the neck, or gatherings in the belly — phlegm-turbidity settled into lumps — seek care first
A cold weak spleen-stomach with thin white phlegm, or unclear lumps — seek care / skip it

Cold and salty, it is not a daily "phlegm-clearing tea" to keep drinking. Clearing when there is no heat-phlegm, or in a cold weak body, chills the middle instead of helping.

When damp-turbidity gathers into heat-phlegm and qi stalls — the sticky plum-rain season, a throat that feels coated, a tight chest — the phlegm sits in the lung; when the phlegm settles into lumps, the neck and belly gather. Fu Shi is cold and salty. It clears the heat-phlegm and dissolves the lumps, which is why it appears in Hai Fu Shi San (Pumice Powder)–type formulas. It dissolves more than it holds. In a cold weak spleen-stomach, or with no heat-phlegm, more makes it worse.

Fu Shi is not a catch-all phlegm or lump herb. In a cold weak spleen-stomach, in pregnancy, with no heat-phlegm, or with lumps of unclear nature, using it alone is a poor match. Whether it belongs in a formula, and at what dose, should be decided by a licensed Chinese medicine practitioner after pattern diagnosis.

Fu Shi: Materia Medica Profile

Identification & Quality Standard

Pumex

Botanical Origin

The porous stone formed by solidification of volcanic magma, mainly composed of SiO2.

Production Regions

Primarily produced in the Chinese provinces of Liaoning, Shandong, Zhejiang, Guangdong, Guangxi, Hainan.

Quality Requirements

Superior medicinal material is light, grayish-white, porous, and floats on water.

Macroscopic Features

Irregular lumps, varying in size; externally grayish-white or grayish-yellow, with numerous fine pores, sponge-like. Light, floats on water; hard and brittle. Fractured surface is loose, often with glass or silky luster. Faint odor, tasteless.

Main Regions and Quality Identification

Classic texts and trade experience favor pumice from volcanic coastal areas of several provinces, but quality still depends on variety, harvest time, processing, and storage — pore density varies with the eruption environment. Good Fu Shi is light gray or gray-white, light and brittle, floats on water, with fine even pores on the break, a faint smell, and a bland taste. The common look-alikes are artificial porous plastics or other rocks — heavier, not floating, often with an odd smell — check carefully.

Traditional Properties & Historical Lineage

Nature, Flavour & Channel Tropism

Salty; ColdLungKidney

1. Records in Classic Materia Medica

Shen Nong Ben Cao Jing: notes it "is used for the water passages, chills and fevers, and gathered accumulations."
Ming Yi Bie Lu: adds it "is used for thirst and difficult urination."
Xin Xiu Ben Cao: records it "is used for cough and rising qi, and eases swellings."
Ben Cao Gang Mu: clarifies it "clears the metal (lung), lowers fire, disperses accumulations, and transforms old phlegm."
De Pei Ben Cao: notes its use for goiter, scrofula, and hernia pain; Zhong Hua Ben Cao sums it as clearing the lung, transforming phlegm, softening hardness, dispersing lumps, and easing urination.

2. How Views of Its Nature Changed

Some doctors leaned on clearing heat-phlegm — for lung-heat with thick phlegm; others stressed the softening and dispersing — for neck lumps and belly gatherings; still others noted the diuretic side — for scanty urine. The differences are not contradictions — they are different emphases for different patterns, which keeps the stone from being a universal remedy.

Core Efficacies & Traditional Applications

Traditional Functions

Clears lung fire, transforms old phlegm, promotes diuresis and unblocks stranguria, softens hard masses and dissipates nodules.

1. Main Use 1: Clearing and Transforming Heat-Phlegm

(1) Traditional action: clearing lung-heat phlegm — thick yellow phlegm from lung heat, hard to bring up. (2) Typical patterns: cough with thick yellow phlegm that sticks, a swollen sore throat, a hoarse voice. (3) Usual pairings: Huang Qin (skullcap) and Sang Bai Pi (mulberry root bark) to strengthen the clearing. (4) Not for self-use: a cold weak body — usually afraid of cold, pale thin phlegm — the cold can add to the internal cold.

2. Main Use 2: Softening Hardness and Dispersing Lumps

(1) Traditional action: dispersing lumps formed by gathered phlegm — goiter in the neck, scrofula (lymph-like swellings), or gatherings in the belly. (2) Typical patterns: neck lumps, scrofula, abdominal gatherings. (3) Usual pairings: Zhe Bei Mu (fritillary) and Hai Zao (seaweed) to strengthen the dispersing. (4) Not for self-use: lumps that may be malignant or of unclear nature — a clinic first; do not delay diagnosis with self-use.

3. A Classic Pairing

Fu Shi pairs classically with Hai Ge Qiao: both clear heat-phlegm and soften hardness — the pumice is cold and porous, clearing the lung's phlegm and promoting urine; the clam shell is cool and heavy, clearing lung fire and curbing acid. Together they strengthen the phlegm-clearing and lump-dispersing, while tending the lung and stomach — for thick heat-phlegm, neck lumps, and excess stomach acid. This pair belongs to a practitioner's pattern diagnosis — no self-pairing.

Modern Research

Modern research offers useful context, but Traditional Chinese Medicine prescribes on whole-pattern diagnosis rather than isolated compounds.

1. Main Chemical Constituents

Detected in the rock are inorganic minerals — silica, alumina, and iron oxide — with traces of magnesium, calcium, and sodium. In vitro, some components inhibit certain bacteria — laboratory results only; in animals, the water decoction appears to regulate respiratory mucus secretion to a degree. Human clinical data are limited to a few case observations — no systematic conclusions.

2. Current Research Directions

Current work runs two lines: the inorganic components' regulation of respiratory secretions, and a possible effect on internal lumps. The porous structure may adsorb some metabolic products — the mechanism and clinical meaning are not yet clear; some components appear to regulate inflammation in experiments — deeper study and human trials are still needed.

3. Limitations of Current Research

Lab results are not clinical efficacy — laboratory and animal results do not copy to people.
Extracts are not decoction pieces — content and action differ by form.
Samples, extraction, and doses vary between studies — results differ.
One component does not define the whole herb — the rock acts as a team of constituents.

Comparing Similar Herbs

1. What They Share

Both clear heat-phlegm and soften hardness, dispersing lumps.
Both are used for lung-heat thick phlegm and neck lumps.
Both appear in phlegm-heat formulas — and both need constitution and dose care.

2. Key Differences

Nature and flavor: Fu Shi is cold and salty, entering the Lung and Kidney, with a diuretic side; Hai Ge Qiao is cool and salty, entering the Lung and Stomach, with an acid-curbing side. Focus: Fu Shi clears the lung's heat-phlegm, softens hardness, and promotes urination — leaning to lung-phlegm heat; Hai Ge Qiao clears lung-stomach heat, softens hardness, and curbs acid — leaning to lung-stomach heat and excess stomach acid. Tendency: Fu Shi descends — from the lung above to the kidney below, guiding the qi down to disperse phlegm; Hai Ge Qiao descends — from the lung above to the stomach in the middle, settling lung qi and harmonizing the stomach. Best fit: Fu Shi for thick yellow phlegm hard to bring up, with scanty urine and a tight chest; Hai Ge Qiao for thick yellow phlegm with burning stomach, excess acid, and neck lumps. Who should avoid: Fu Shi's cold is wrong for a cold weak spleen-stomach with frequent belly pain and loose stools; Hai Ge Qiao's coolness is also wrong for a cold weak spleen-stomach with cold stomach pain and thin stools — neither suits a cold body. Where you meet them: Fu Shi in lung-formulas for heat-phlegm cough; Hai Ge Qiao in lung-stomach formulas for excess acid and burning stomach, and in neck-lump formulas.

3. One-Line Takeaway

In short, Fu Shi clears the lung's heat-phlegm, softens hardness, and promotes urine; Hai Ge Qiao clears lung-stomach heat, softens hardness, and curbs acid. Both can appear in phlegm-heat care — but they are not stand-ins for each other.

Classical Formulas Containing Fu Shi

Classic Formula 1: Hai Fu Shi San

Role of this herb: in Hai Fu Shi San (Pumice Powder), Fu Shi is the monarch — clearing heat-phlegm and softening hardness — with Gua Lou Ren (trichosanthes seed) and Dan Nan Xing (bile-processed arisaema) strengthening the phlegm-clearing, and Xiang Fu (nutgrass rhizome) and Yu Jin (turmeric root tuber) sorting the qi. The target is lung-heat thick phlegm with qi not running — cough, a tight chest, neck lumps; alone, the stone cannot also sort the qi. Traditional focus: heat-phlegm cough, goiter and scrofula, tight chest and flank pain. Modern note: professional diagnosis first — never self-apply by name.

Classic Formula 2: Xiao Luo Wan

Role of this herb: in Xiao Luo Wan (Scrofula-Dissolving Pill), Fu Shi is a minister — with Zhe Bei Mu and Hai Zao softening hardness and dissolving scrofula — and Xuan Shen (figwort root) and Mu Li (oyster shell) nourishing yin and lowering fire. The target is neck lumps from gathered phlegm with yin-deficiency fire; alone, the stone cannot also nourish the yin. Traditional focus: scrofula and phlegm nodules. Modern note: professional diagnosis first — for neck lumps of unclear nature, a clinic before anything else.

Formula vs. Single Herb

A formula is a coordinated team — covering several mechanisms at once; a single herb cannot copy a full formula's effect. The doses and pairings are designed as a whole — a herb that works in a formula does not automatically work the same way alone. Do not self-formulate from web articles.

Diet & Daily Home Use

1. Home Tea and Soup

Example 1 — Fu Shi phlegm-clearing tea: raw Fu Shi 3 g, chrysanthemum 2 g, Chen Pi 1 g — wrap in gauze, steep in boiling water 10 minutes, re-steep until faint. Fit: daily care for lung-heat thick phlegm and a sticky throat, useful in the plum-rain or hot season. Not for: a cold weak spleen-stomach with frequent belly pain and loose stools. Frequency: 2–3 times a week, not long-term. Fu Shi is a medicinal piece — not ordinary tea; keep the dose under a practitioner's guidance. Example 2 — Fu Shi kelp soup: raw Fu Shi 5 g, kelp 10 g, lean meat 50 g — wrap the stone in gauze, simmer in a clay pot 1 hour, season lightly. Fit: daily care for gathered phlegm with mild neck lumps, for heat-leaning bodies. Not for: pregnancy and a cold weak spleen-stomach. Frequency: 1–2 times a month, not frequent.

2. Decoction and Processing Differences

The raw stone is hard — boil it first for 30 minutes before adding other herbs; the calcined stone is loose — decoct with the others. No wrapped, late-added, or swallowed-powder steps. The forms differ slightly: the raw leans to clearing heat-phlegm; the calcined leans to softening hardness — choose by the need. Different forms — pieces, pills, powders — cannot be converted directly; follow professional guidance.

3. Dosage and How Long to Use

The classic range is 5–10 g, adjusted to the pattern; food-use amounts are 3–5 g. Not for long continuous use — generally no more than 2 weeks; if the symptom does not ease or worsens, stop and seek care. Pregnant and nursing women, children, and people with liver or kidney impairment use it only under a practitioner or pharmacist.

Contraindications & Safety Warnings

1. Who Should Avoid It

A cold weak body — usually afraid of cold, pale thin phlegm; pregnancy and nursing — consult a practitioner; children and the elderly — weaker liver and kidney function, adjust the dose, no self-use; liver or kidney impairment — avoid, to protect the organs; allergy to the stone or related minerals — avoid; people on anticoagulant, blood-pressure, or blood-sugar medicines — consult a practitioner first.

2. Interactions and Diet Notes

Fu Shi may interact with anticoagulants — anyone on them should avoid; with blood-pressure and blood-sugar medicines, doses may need adjusting — consult a practitioner; with sedatives, the calming may strengthen — be cautious. No blanket "food clash" with ordinary foods is established, but herbs can interact with specific medicines — anyone on medication should check first.

3. Side Effects and Overuse

Overuse can bring spleen-stomach discomfort — belly pain and diarrhea; a few people get allergic reactions — rash, itching. Keep to the dose under a practitioner's or the package's guidance — never raise it on your own. Stop and seek care at once for marked discomfort, an allergic reaction, persistent vomiting, trouble breathing, confusion, or a rapid worsening of symptoms.

Frequently Asked Questions About Fu Shi

What is Fushi? Is it the same as Haifushi or Mengshi?

Fushi is the porous stone formed from solidified volcanic magma, Latin name Pumex. It is a common Chinese medicine centered on clearing the lung and transforming phlegm, softening hardness and dissipating binds, and promoting urination and freeing strangury. Haifushi is related. Mengshi drives phlegm downward and descends qi while calming the liver. They cannot be used interchangeably in equal amounts. Prescribe as Fushi. Caution in deficiency cold phlegm-fluid.

What are the composition and effects of Fushi?

Pharmacopoeial name Fushi. Salty in taste, cold in nature, enters the Lung meridian. Functions to clear the lung and transform phlegm, soften hardness and dissipate binds, and promote urination and free strangury. Used for phlegm-heat congesting the lung, cough with counterflow and rapid breathing, thick yellow phlegm, scrofula, goiter, and stone strangury. Clears the lung and transforms phlegm.

How to choose between raw and processed? Can Mengshi replace it?

Stone is used raw or calcined. Mengshi emphasizes driving phlegm downward rather than strongly clearing the lung, and cannot replace it in equal amounts. Commercial products are standardized; do not adjust arbitrarily.

What is the dosage of Fushi? Can it be used daily as a phlegm-transforming tea?

Decoction, 10-15g, decocted first. Modern use requires physician-determined dosage. It is not a year-round "Fushi tea." Deficiency cold phlegm-fluid will be further injured by prolonged use. Cough and dyspnea require short-term, physician-determined dosage and cannot replace evaluation.

What are the contraindications of Fushi? Can pregnant women use it?

Not suitable for deficiency cold phlegm-fluid. Pregnant women require physician evaluation. Stop if loose stools or abdominal pain occur. Seek immediate medical care for severe cough and dyspnea or high fever.

Can Fushi clear the lung, transform phlegm, and soften hardness?

It can assist phlegm-heat congesting the lung, cough with counterflow and rapid breathing, thick yellow phlegm, scrofula, goiter, and stone strangury. It clears the lung and transforms phlegm, softens hardness and dissipates binds, and promotes urination and frees strangury, but is not a specific remedy for all cough and dyspnea or all scrofula.

Can Fushi be taken daily as a phlegm-transforming or hardness-softening tea?

Phlegm-heat cough and dyspnea can be used short-term in formulas; deficiency cold phlegm-fluid will be further injured. The idea that "Fushi must transform phlegm" cannot replace evaluation. Clearing the lung and transforming phlegm requires physician-determined formulation and dosage.

How to choose between Fushi, Haifushi, Mengshi, Gualou, and Beimu?

Fushi clears the lung and softens hardness, suited to phlegm-heat. Haifushi is related. Mengshi drives phlegm downward and calms the liver. Gualou clears heat and transforms phlegm while broadening the chest. Beimu clears heat and transforms phlegm while moistening the lung. Choose Fushi for transforming phlegm; Mengshi for driving phlegm downward; Gualou for broadening the chest; Beimu for moistening the lung. Pattern differentiation applies, but large doses of Fushi are contraindicated in deficiency cold phlegm-fluid.

How is Fushi commonly modified? What is a representative usage?

Modifications depend on the pattern. Add Gualou for phlegm-heat; add Beimu for scrofula. Specify Fushi; do not substitute Mengshi in equal amounts for clearing the lung.

How to select and store Fushi?

Choose regular Chinese medicinal materials with intact stones. Discard if moldy, damp, or abnormal in odor. Store in a dry place. Purchase "Fushi"; do not substitute Mengshi or Gualou in equal amounts for clearing the lung, transforming phlegm, and softening hardness.

Related Products

Nong's Fu Shi (Pumice Stone) Single Herb 5:1 Concentrated Granules $50.03

Hoi Tin Fu Shi (Pumice) Single Herb 20:1 Concentrated Granules, 100 g TCM Herbal Supplement

Hoi Tin Fu Shi (Pumice) Single Herb 20:1 Concentrated Granules $24.77

Medical Disclaimer — This article is provided for educational purposes only and describes traditional Chinese medicine concepts. It is not medical advice, and it is not intended to diagnose, treat, cure or prevent any disease. Always consult a qualified practitioner before using any herb, particularly if you are pregnant, nursing, taking medication or managing a diagnosed condition.