Ingredient Mineral (矿物 kuàng wù)

Fu Hai Shi

Pumice · 浮海石

Costazia aculeata Canu et Bassler / Pumice (volcanic rock) · Costaziae Os / Pumex

Also known as: Hai Fu Shi (海浮石)

Fu Hai Shi (Pumice) plant

Images shown are for educational purposes only

Fu Hai Shi is a marine-derived substance (either the skeletal remains of certain sea organisms or volcanic pumice) used to clear heat from the lungs and dissolve stubborn, sticky phlegm. It is commonly used for chronic coughs with thick yellow sputum, thyroid nodules, and urinary difficulties. Its salty and cold nature gives it the ability to soften hard lumps and cool inflammatory heat in the respiratory system.

Category Herbs that cool and transform Phlegm-Heat (清化热痰药)
Therapeutic focus Respiratory Health Thyroid and Lymph Node Support Urinary Health

TCM Properties

Temperature

Cold

Taste

Salty (咸 xián)

Channels entered

Lungs, Kidneys

Parts used

Mineral (矿物 kuàng wù)

Educational content • Consult qualified TCM practitioners for diagnosis and treatment

What This Ingredient Does

Every ingredient has a specific set of actions — here's what Fu Hai Shi does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Fu Hai Shi is primarily used to support these areas of health:

Respiratory Health Thyroid and Lymph Node Support Urinary Health

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Fu Hai Shi performs to restore balance in the body:

Clears Lung Heat and Transforms Phlegm Dissipates Nodules and Softens Hardness Promotes Urination and Relieves Stranguria

How these actions work

'Clears Lung Heat and transforms Phlegm' means Fu Hai Shi cools down inflammatory heat in the lungs and helps dissolve thick, sticky phlegm that is difficult to cough up. Its salty taste has a natural softening and dissolving quality, making it particularly effective for old, stubborn phlegm that has congealed over time. This action is most relevant for chronic coughs with thick yellow sputum, or coughing up blood-streaked phlegm due to heat scorching the lung.

'Softens hardness and dissipates nodules' refers to Fu Hai Shi's ability to break down and reduce firm lumps and swellings. In TCM, this encompasses conditions like goiter (yǐng liú), scrofula (luǒ lì, or lymph node tuberculosis), and other palpable masses that form when phlegm and heat congeal together. The salty taste is considered to have a natural affinity for softening hard accumulations.

'Promotes urination and unblocks painful urinary dysfunction' reflects a principle where clearing heat from the Lungs (which TCM considers the 'upper source of water') helps regulate the waterways below. By clearing Lung Heat and restoring the Lung's descending function, Fu Hai Shi helps resolve painful or bloody urination (blood strangury) and urinary stones (stone strangury). It is often combined with herbs like Xiao Ji (Small Thistle) or Pu Huang (Cattail Pollen) for these urinary conditions.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Fu Hai Shi is used to help correct these specific patterns.

Why Fu Hai Shi addresses this pattern

Fu Hai Shi's cold nature directly clears the heat component of this pattern, while its salty taste softens and dissolves the congealed phlegm. It enters the Lung channel and is especially suited for chronic, stubborn phlegm that has thickened and become difficult to expectorate. The herb's lightweight, porous physical nature (it floats on water) reflects its affinity for the Lungs, which occupy the highest position among the organs. This makes it a targeted choice for phlegm-heat lodged in the upper body.

A practitioner would look for one or more of these signs

Hypochondrial Pain That Is Worse On Coughing And Breathing

Chronic cough with thick, sticky yellow sputum

Hemoptysis

Coughing up blood-streaked phlegm due to heat

Wheezing

Wheezing with difficulty expectorating

Commonly Used For

These are conditions where Fu Hai Shi is frequently used — but only when they arise from the specific patterns it addresses, not in all cases

Arises from: Phlegm-Heat in the Lungs

TCM Interpretation

TCM views chronic bronchitis primarily as a disorder of the Lung's descending and dispersing functions. When heat and phlegm accumulate in the Lungs over time, the phlegm becomes thick, sticky, and difficult to clear. The Lung loses its ability to properly descend Qi, leading to coughing, wheezing, and a feeling of chest congestion. In many chronic cases, the phlegm has been present so long that it has become what TCM calls 'old phlegm' (lǎo tán), which requires stronger dissolving action than ordinary phlegm-clearing herbs can provide.

Why Fu Hai Shi Helps

Fu Hai Shi is specifically noted in classical texts for its ability to dissolve old, stubborn phlegm. Its cold nature clears the heat that is generating and thickening the phlegm, while its salty taste has a natural softening and dissolving action on congealed substances. Zhu Danxi (a famous Yuan Dynasty physician) specifically praised it for its ability to 'clear the Lungs, descend fire, dissolve old phlegm, and disperse accumulations.' This makes it well-suited for chronic bronchitis where the sputum is yellow, thick, and difficult to expectorate.

Also commonly used for

Bronchiectasis

Particularly with blood-streaked sputum

Hemoptysis

Due to heat scorching the lung vessels

Reactive Lymphadenopathy

Scrofula or cervical lymph node tuberculosis

Urinary Tract Stones

Stone strangury

Hematuria

Blood strangury with painful urination

Asthma

Phlegm-heat type with thick sputum

Pulmonary Tuberculosis

With coughing of blood and thick phlegm

Ingredient Properties

Every ingredient has an inherent temperature, taste, and affinity for specific channels — these properties determine how it interacts with the body

Temperature

Cold

Taste

Salty (咸 xián)

Channels Entered

Lungs Kidneys

Parts Used

Mineral (矿物 kuàng wù)

Dosage & Preparation

These are general dosage guidelines for Fu Hai Shi — always follow your practitioner's recommendation, as dosages vary based on the formula and your individual condition

Standard dosage

9–15g

Maximum dosage

Up to 30g in severe phlegm-heat conditions, under practitioner supervision. Some clinical reports describe larger doses for specific conditions such as haemoptysis, but this requires professional guidance.

Dosage notes

Use the lower end of the range (9–10g) for milder phlegm conditions or as part of a larger formula. Higher doses (12–15g) are appropriate for stubborn, chronic phlegm-heat cough with thick yellow sputum, or for nodular conditions like scrofula and goitre. When used for urinary conditions (blood in urine, urinary stones), it may be ground into a fine powder and taken directly with warm water rather than decocted. For external use (eye disorders), process by water-levigation (水飞) to produce an ultra-fine powder.

Preparation

Crush or break into small pieces and decoct first (打碎先煎, da sui xian jian) for 20–30 minutes before adding other herbs, as this hard mineral/skeletal substance requires longer cooking to release its active components. For external eye use, process by water-levigation (水飞, shui fei) to produce an extremely fine, non-irritating powder. Before use, the raw material should be soaked in clean water for 3–4 days (weighed down to stay submerged) to remove salt and marine impurities, then washed and dried.

Processing Methods

In TCM, the same ingredient can be prepared in different ways to change its effects — here's how processing alters what Fu Hai Shi does

Processing method

The raw herb is placed in a suitable container and heated with strong, smokeless fire until red-hot throughout. It is then removed, allowed to cool, and crushed into smaller pieces or powder. Some traditions quench the red-hot stone in vinegar (cù cuì) before crushing.

How it changes properties

Calcining makes the herb more brittle and easier to crush into fine powder, which improves its ability to be decocted and absorbed. The thermal nature remains cold but the softening and dissipating actions on hard nodules are enhanced. The calcined form is preferred when the focus is on softening hardness and dissipating nodules rather than clearing phlegm from the lungs.

When to use this form

Use the calcined form when the primary treatment goal is to soften and dissolve hard masses such as goiter, scrofula, or chronic skin sores. Also used externally as a fine powder for topical application on sores and ulcers.

Common Ingredient Pairs

These ingredients are traditionally combined with Fu Hai Shi for enhanced therapeutic effect

Gua Lou
Gua Lou 1:1 (Fu Hai Shi 9-15g : Gua Lou 9-15g)

Fu Hai Shi dissolves old, stubborn phlegm with its salty-cold properties, while Gua Lou (Trichosanthes Fruit) moistens the Lungs, clears heat, and loosens phlegm with its sweet-cold nature. Together they provide a comprehensive approach to thick, tenacious phlegm-heat in the chest, as Fu Hai Shi breaks down congealed phlegm while Gua Lou makes it easier to expectorate.

When to use: Phlegm-heat cough with thick, sticky yellow sputum that is very difficult to bring up, often with chest fullness and tightness.

Qing Dai
Qing Dai 3:2 (Fu Hai Shi 9g : Qing Dai 6g)

Fu Hai Shi clears Lung heat and dissolves phlegm, while Qing Dai (Indigo Naturalis) clears Liver fire and cools the Blood. Together they address the pattern of Liver fire attacking the Lungs, which causes coughing with blood-streaked sputum. This pairing is the core of the famous Ke Xue Fang (Coughing Blood Formula).

When to use: Coughing up blood-streaked or blood-stained sputum with irritability, rib-side pain, and bitter taste in the mouth, indicating Liver fire scorching the Lungs.

Mu Li Ke
Mu Li Ke 1:2 (Fu Hai Shi 9-15g : Mu Li 15-30g)

Both herbs are salty and cold with the ability to soften hardness and dissipate nodules, but they work through complementary mechanisms. Fu Hai Shi primarily clears Lung phlegm-heat and dissolves phlegm masses, while Mu Li (Oyster Shell) anchors floating Yang, calms the spirit, and has a stronger astringent quality. Together they powerfully address phlegm-fire nodules.

When to use: Goiter, thyroid nodules, scrofula, or other palpable masses caused by phlegm-fire accumulation, especially when accompanied by irritability or restlessness.

Xiang Fu
Xiang Fu 1:1, powdered and taken with fresh ginger juice

Fu Hai Shi softens hardness and clears heat, while Xiang Fu (Cyperus) moves Qi and resolves stagnation. The combination addresses the interplay between Qi stagnation and phlegm congelation. This classical pairing from the Dan Xi Xin Fa is used for hernial conditions where Qi stagnation and phlegm-heat combine.

When to use: Hernia with scrotal swelling and pain, or abdominal masses with Qi stagnation and phlegm-heat.

Comparable Ingredients

These ingredients have overlapping uses — here's how to tell them apart

Zh
Fu Hai Shi vs Zhe Bei Mu

Both clear heat and transform phlegm, but Zhe Bei Mu (Zhejiang Fritillary) is bitter-cold and stronger at clearing fire and dissipating phlegm nodules, while also being more commonly used for upper respiratory infections. Fu Hai Shi is salty-cold and specializes in dissolving old, congealed phlegm and has a stronger softening action on hard masses like goiter. Fu Hai Shi also has the additional action of promoting urination for strangury, which Zhe Bei Mu lacks.

Ha
Fu Hai Shi vs Hai Ge Ke

Both are salty-cold marine substances that clear Lung heat and transform phlegm. However, Hai Ge Ke (Clam Shell) has a stronger action of softening hardness and controlling acid for stomach conditions, and is more commonly used for phlegm nodules in the breast. Fu Hai Shi is lighter and more buoyant in nature, giving it a stronger affinity for the upper body and Lungs, and it additionally treats urinary strangury.

Kun Bu
Fu Hai Shi vs Kun Bu

Both soften hardness and dissipate nodules, making them useful for goiter and scrofula. However, Kun Bu (Kelp Thallus) is salty-cold and specifically targets phlegm in the neck region with a focus on dispersing goiter, while Fu Hai Shi has a broader range including clearing Lung phlegm-heat and treating urinary conditions. They are often used together for thyroid nodules.

Identity & Adulterants

Related species and common adulterations to be aware of when sourcing Fu Hai Shi

The two main forms of this medicine, Costazia bryozoan skeleton (石花) and volcanic pumice (浮石), are sometimes used interchangeably, though their chemical compositions differ significantly. The Costazia type is mainly calcium carbonate, while the pumice type is mainly silicon dioxide. Modern pharmacopoeias distinguish between them. Adulterants may include other marine calcareous materials such as coral fragments or heavily encrusted shell debris. Authentic Costazia skeleton should show characteristic branching coral-like morphology with fine pores. Authentic pumice should be extremely light and float readily on water. Pieces contaminated with excess salt, mud, sand, or marine organisms (barnacles, algae) indicate poor processing.

Educational content — always consult a qualified healthcare provider or TCM practitioner before using any ingredient.

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Fu Hai Shi

Non-toxic

Fu Hai Shi is classified as non-toxic. The Ben Cao Shi Yi states it is "non-toxic" (无毒). The Costazia skeleton type is primarily composed of calcium carbonate with small amounts of magnesium and iron. The pumice type is mainly silicon dioxide with aluminium oxide and potassium oxide. Neither contains known toxic compounds at standard medicinal doses. The primary safety concern is not toxicity but rather its strongly cold nature, which may injure the Spleen and Stomach with prolonged or excessive use.

Contraindications

Situations where Fu Hai Shi should not be used or requires extra caution

Avoid

Deficiency-cold cough (虚寒咳嗽): Fu Hai Shi is salty and cold in nature. It should not be used for cough caused by cold or deficiency patterns, where the sputum is thin, white, and watery rather than thick and yellow. Using this cold herb in such cases would further damage the Spleen and Lung Yang.

Caution

Spleen and Stomach deficiency-cold (脾胃虚寒): As a cold and salty substance, prolonged or excessive use can injure the Spleen and Stomach. Classical sources such as the Ben Cao Hui Yan warn that long-term use may harm the digestive function. People with weak digestion, chronic loose stools, or poor appetite should avoid this herb.

Caution

Yin-deficiency dry cough without phlegm: This herb is designed to transform thick, stubborn phlegm-heat. If the cough is dry with little or no sputum, arising from Lung Yin deficiency, Fu Hai Shi's drying and cold properties are inappropriate.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

No specific pregnancy contraindication is documented in classical or modern sources. However, given its cold and salty nature, caution is advisable during pregnancy. Cold herbs can potentially impair Spleen function and affect digestion, which is already vulnerable during pregnancy. Use only under practitioner guidance.

Breastfeeding

No specific contraindication for breastfeeding is documented. As a mineral/animal skeletal substance, significant transfer through breast milk is unlikely. However, its cold nature could theoretically affect the mother's digestion and milk production if used in excess. Use with caution and only at standard doses under practitioner guidance.

Children

Fu Hai Shi has historically been used in paediatric formulas for phlegm-heat cough and childhood asthma. Dosage should be reduced proportionally for children, typically to one-third to one-half the adult dose depending on age and weight. Its cold nature makes it unsuitable for children with weak digestion or Spleen deficiency. Use only under qualified practitioner supervision.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Fu Hai Shi

No well-documented pharmaceutical drug interactions have been established for Fu Hai Shi in peer-reviewed literature. However, given its primary composition (calcium carbonate in the Costazia type), some theoretical considerations apply:

  • Calcium-containing medications: Concurrent use with calcium supplements could theoretically increase total calcium intake. Relevant for patients on calcium supplementation or with hypercalcaemia risk.
  • Tetracycline and fluoroquinolone antibiotics: Calcium carbonate can reduce the absorption of these antibiotics by forming insoluble chelates. If using the Costazia-type Fu Hai Shi, separate administration by at least 2 hours.
  • Antacids: The calcium carbonate content may have additive antacid effects. May alter gastric pH and affect absorption of pH-dependent medications.

These are theoretical considerations based on chemical composition, not clinically documented interactions specific to Fu Hai Shi. Patients taking prescription medications should consult their healthcare provider.

Dietary Advice

Foods and dietary considerations when taking Fu Hai Shi

Avoid excessively cold or raw foods while taking Fu Hai Shi, as its cold nature can further burden the Spleen and Stomach. Warm, easily digestible foods are preferred. If experiencing any digestive discomfort, pairing with warming foods like ginger tea can help offset its cold properties.

Botanical Description

Physical characteristics and morphology of the Fu Hai Shi source mineral

Fu Hai Shi (浮海石) is not a plant but rather a marine-origin mineral or animal substance used in TCM. It comes from two main sources:

1. Costazia skeleton (石花, Shi Hua): The dried calcareous skeletons of colonial marine bryozoans (moss animals), primarily Costazia aculeata Canu et Bassler and Costazia costazii (Audouin). These tiny colonial organisms live attached to seaweed, shells, and coral reefs. They secrete a calcium carbonate and gelatinous matrix that forms coral-like branching skeletal structures. When the organisms die, the remaining greyish-white to yellowish skeleton is collected. The pieces are irregular, coral-like, with forked branches and a networked structure, and are light enough to float in water.

2. Pumice (浮石, Fu Shi): A volcanic rock formed when gas-rich lava is ejected during eruptions and rapidly solidifies into a highly porous, frothy glass. The resulting stone is so light and full of air pockets that it floats on water. It is non-crystalline, mainly composed of silicon dioxide (SiO2), aluminium oxide (Al2O3), and potassium oxide (K2O). Pieces are irregularly shaped, greyish-white, rough-surfaced, hard but brittle, and may show a silky or glassy lustre on the broken surface.

Sourcing & Harvesting

Where Fu Hai Shi is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Costazia skeletons are harvested mainly in summer and autumn (June to October). Pumice can be collected year-round but is most commonly gathered in summer.

Primary growing regions

Fu Hai Shi is a marine-sourced substance collected from coastal waters rather than grown in fields. Costazia skeleton (石花, Shi Hua): Primarily harvested from the coastal waters of Zhejiang and Fujian provinces. Pumice-type (浮石): Collected along the coasts of Liaoning, Shandong, Fujian, and Guangdong provinces. The broader distribution of the bryozoan source extends from Shandong Peninsula southward through Jiangsu, Zhejiang, Fujian, Guangdong, Hainan, and the South China Sea islands (Xisha, Zhongsha, Nansha). The best quality Costazia-type material traditionally comes from Zhejiang and Fujian.

Quality indicators

Costazia skeleton type (石花): Good quality pieces are coral-like in shape, greyish-white in colour, lightweight, with clearly visible forked branching structures and a porous, net-like texture. Should float in water. Slightly fishy smell, slightly salty taste. Avoid dark, heavy, or heavily contaminated pieces. Pumice type (浮石): Good quality is lightweight enough to float on water, greyish-white in colour, with numerous small pores evenly distributed. Texture is hard but brittle, and the fracture surface may show a silky or glassy sheen. Should have a faint smell and mild or bland taste. Avoid pieces that are too heavy, dark-coloured, or that sink in water.

Classical Texts

Key passages from the classical Chinese medical texts that describe Fu Hai Shi and its therapeutic uses

Ben Cao Shi Yi (《本草拾遗》, Tang Dynasty, Chen Cangqi)

Original: 平，无毒。主渴。
Translation: "Neutral in nature, non-toxic. Mainly treats thirst."

This is one of the earliest recorded references to this substance, noting its mild nature and use for thirst.

Zhu Zhenheng (朱震亨, Yuan Dynasty)

Original: 清金降火，消积块，化老痰。
Translation: "Clears the Lung [Metal], descends Fire, disperses accumulated masses, and transforms old, stubborn phlegm."

Zhu Danxi was the first to clearly articulate Fu Hai Shi's role in clearing Lung Fire and dissolving chronic phlegm accumulations.

Ben Cao Gang Mu (《本草纲目》, Li Shizhen)

Original: 消瘿瘤结核疝气，下气，消疮肿。
Translation: "Disperses goitre, tumours, scrofula, and hernial disorders; descends Qi; and reduces sores and swelling."

Ben Cao Zheng (《本草正》)

Original: 消食，消热痰，解热渴热淋，止痰嗽喘急，软坚癥，利水湿。
Translation: "Aids digestion, eliminates hot phlegm, relieves heat-thirst and heat-related painful urination, stops phlegm-cough and urgent wheezing, softens hard masses, and promotes water metabolism."

Ben Cao Hui Yan (《本草汇言》)

Original: 海浮石性寒，久服恐伤脾胃，须配伍温中药调和。
Translation: "Fu Hai Shi is cold in nature; prolonged use may injure the Spleen and Stomach. It must be combined with warming, Spleen-harmonising herbs."

Historical Context

The history and evolution of Fu Hai Shi's use in Chinese medicine over the centuries

The name Fu Hai Shi (浮海石) literally means "stone that floats in the sea," a vivid description of how this remarkably light substance was first noticed by coastal peoples as it drifted on the ocean surface. The herb has been known by many names throughout history, including Shui Hua (水花, "water flower"), Hai Shi (海石, "sea stone"), and Yang Du Shi (羊肚石, "sheep stomach stone," from its porous resemblance to the lining of a sheep's stomach).

The earliest recorded medicinal use appears in Chen Cangqi's Ben Cao Shi Yi (《本草拾遗》) of the Tang Dynasty, where it was described as neutral and non-toxic, and used primarily for thirst. The herb's role expanded significantly during the Yuan Dynasty, when the great physician Zhu Zhenheng (朱震亨, also known as Zhu Danxi) identified it as a key substance for clearing Lung Fire and dissolving old, stubborn phlegm. His formula Ke Xue Fang (咳血方, "Cough-Blood Formula") from the Dan Xi Xin Fa pairs Fu Hai Shi with Qing Dai, Zhi Zi, and Gua Lou to treat Liver-Fire scorching the Lungs with chronic cough and blood-streaked sputum. Li Shizhen's Ben Cao Gang Mu further expanded its recorded indications to include goitre, scrofula, hernial disorders, and sores. Over time, the understanding of this substance deepened from a simple thirst-quenching agent to a specialised phlegm-heat and nodule-dissolving medicine.

An interesting point of confusion runs throughout the herb's history: "Fu Hai Shi" actually encompasses two quite different substances (volcanic pumice rock and bryozoan skeletons) that share the common trait of being lightweight, porous, and marine-derived. Modern pharmacopoeias have attempted to clarify this by distinguishing Hai Fu Shi (海浮石, the bryozoan skeleton) from Fu Shi (浮石, the volcanic pumice), though in clinical practice they are often used interchangeably.