Fruits and seedsTonifyingBroussonetiae Fructus

Chu Shi Zi (Paper Mulberry Fruit)

Q: What is Chu Shi Zi? Are Gou Qi Zi and Sang Shen the same?

Official Chu Shi Zi (楮实子) is the dried ripe fruit of Broussonetia papyrifera . The pharmacopoeial name is Broussonetiae Fructus . It is also called paper-mulberry fruit. Gou Qi Zi is sweet and neutral: nourishes the Liver and Kidney, boosts essence and brightens the eyes. Sang Shen is sweet-sour and cold: nourishes yin, supplements Blood, generates fluid and moistens dryness. Write Chu Shi Zi. Use caution in Spleen-Stomach vacuity cold.

Q: What are the TCM properties and traditional uses of Chu Shi Zi?

According to the Chinese Pharmacopoeia, Chu Shi Zi is sweet and cold , enters the Liver and Kidney channels, and acts to supplement the Kidney, clear the Liver, brighten the eyes and promote urination . It is used for Liver-Kidney insufficiency, sore weak waist and knees, vacuity-taxation steaming bone, dizziness and dim vision, eye films, and edema with fullness. Sweet, cold and clearing, it suits Liver-Kidney insufficiency with vacuity heat—not Spleen-Stomach vacuity cold or loose stool.

Q: What is the usual dosage? Can it be drunk daily as an eye tea?

The pharmacopoeial decoction dose is 6–12 g . It is not a four-season “paper-mulberry eye tea.” Spleen-Stomach vacuity cold only loosens further as it cools. Dim vision and edema need a practitioner to name a short course; they do not replace eye or medical assessment.

Q: How do you choose and store Chu Shi Zi?

Choose nearly spherical or ovoid fruits, reddish brown, netted, ridged on one side, hard and brittle, a whitish oily endosperm, a faint odor and a bland taste . Lots with much persistent calyx, mold, moths or a rancid odor are discarded. Store ventilated and dry. Buy pharmacopoeial Chu Shi Zi; do not replace supplementing the Kidney, clearing the Liver, brightening the eyes and promoting urination with lycium fruit or mulberry fruit by equal weight.

A practical guide to Chu Shi Zi: 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 13, 2026

Quick Facts

Latin Name	Broussonetiae Fructus
Chinese Name & Pinyin	楮實子 · Chu Shi Zi
Medicinal Part	Fruits and seeds
The herb	Chu Shi Zi is the dried ripe fruit of Broussonetia papyrifera. Gou Qi Zi and Tu Si Zi are different official drugs.
Nature and channels	Sweet, cold. Enters the Liver and Kidney. Sweetness tonifies the Kidney. Cold clears the Liver, brightens the eyes, and promotes urine.
Pharmacopoeia line	Tonifies the Kidney and clears the Liver. Brightens the eyes. Promotes urination. Used for Liver–Kidney insufficiency, sore lumbar region and knees, consumptive steaming bone, dizziness and dim vision, eye screens, and edema and fullness.
Pattern cues	Dim vision. Sore lumbar region and knees. Steaming bone. Edema. Red tongue.
In this article	Chu Shi Zi versus Gou Qi Zi, Tu Si Zi, and Che Qian Zi. Clearing tonification versus warm tonification. Why a weak spleen should skip it. Why eye screens need a clinic. Who should skip it.

What Is Chu Shi Zi?

Chu Shi Zi (楮实子; Chǔ Shí Zǐ; Latin: Broussonetiae Fructus; English: paper mulberry fruit) is the dried ripe fruit of Broussonetia papyrifera (L.) Vent. In Chinese medicine it is a yin-nourishing herb. It is sweet and cold, enters the Liver and Kidney channels, and its core actions are to tonify the Kidney and clear the Liver, brighten the eyes, and promote urination. The teaching point is dim vision from Liver–Kidney insufficiency, with edema beside it. It is not Gou Qi Zi. Lycium fruit is sweet and neutral. It nourishes Liver and Kidney and boosts essence to brighten the eyes. It is not cold, and promoting urine is not its main work. Chu Shi Zi is sweet-cold. Clearing the Liver and promoting urine are more specific. Roadside paper-mulberry fruit is not the official piece. A cold weak spleen and loose stools are a poor match. Eye screens and edema need a clinic. This is not a vision product claim.

It is used most often for three patterns:

Liver–Kidney insufficiency — sore lumbar region and knees, dizziness and dim vision
Consumptive steaming bone — this needs pattern diagnosis
Edema and fullness — seek care

The usual decoction dose is 6–12 g. Sweet and cold, it is not a daily “vision paper-mulberry” tea. Cold draining with no heat injures middle yang.

When Liver and Kidney insufficiency carries heat, or water-damp collects, dim vision, sore lumbar region, and edema are common. Chu Shi Zi is sweet-cold. It tonifies, clears, and promotes urine, which is why it appears in Liver–Kidney clearing-tonifying formulas. It cools and drains more than it warms. Loose stools and fear of cold get worse if more is added.

Chu Shi Zi is not a catch-all vision or diuretic fruit. In middle-cold diarrhea, or when there is no heat and no dampness, using it alone can cool and injure the middle. Whether it belongs in a formula should be decided by a licensed Chinese medicine practitioner after pattern diagnosis.

Chu Shi Zi: Materia Medica Profile

Identification & Quality Standard

Broussonetiae Fructus

Botanical Origin

The dried mature fruit of Broussonetia papyrifera (L.) Vent.(Moraceae).

Production Regions

Primarily produced in the Chinese provinces of Shanxi, Gansu, Hebei, Hunan, Hubei.

Quality Requirements

Superior medicinal material is red, old-seed, and lack of foreign matter.

Macroscopic Features

Small achene is flat spherical or oval, 2mm long, 1.5~2mm wide. Externally orange-red or brownish-red, with reticular wrinkles or granular protrusions, one side with slightly flat or an indented groove, other side with a ridge, base has scars of ovary. Hard texture, with one seed inside; seed coat is reddish-brown; kernel is white, oily. Tasteless.

Authentic Regions and Quality Identification

Traditional literature and industry experience often highlight specific regions, but the actual quality is influenced by the variety, harvest time, processing methods, and storage conditions. The paper mulberry tree is widely distributed across China, growing in southern regions like Zhejiang, Jiangsu, and Sichuan, as well as northern areas like Hebei and Henan.

Appearance of High Quality: Premium Chu Shi Zi is ovate or broadly ovate, reddish-brown to dark brown in color. It has a reticulated (net-like) wrinkled surface with a small protrusion at the top. The texture is slightly hard, and when broken open, it reveals a yellowish-white kernel. It has a mildly sweet taste.
Common Confusions: It can be confused with similar-looking small fruits from other plants, such as certain Rosaceae species. However, these imposters usually lack the distinct net-like wrinkles and the specific kernel structure of Chu Shi Zi, and they also differ significantly in smell and taste.

Traditional Properties & Historical Lineage

Nature, Flavour & Channel Tropism

Sweet; ColdLiverKidney

1. Historical Records in Classic Texts

Shen Nong Ben Cao Jing (The Divine Farmer's Materia Medica) classifies Chu Shi Zi as a top-grade herb, noting its use for "Yin impotence, edema, boosting Qi, filling the flesh and skin, and brightening the eyes."
Ming Yi Bie Lu (Miscellaneous Records of Famous Physicians) adds that it "treats lower back and knee pain, tonifies the middle, boosts essence and Qi; taken long-term, one will not feel hungry and will not age."
Ben Cao Gang Mu (Compendium of Materia Medica) mentions it "nourishes Yin and promotes water metabolism, treats bone-steaming labor heat, brightens the eyes, and strengthens bones and sinews."
De Pei Ben Cao (Materia Medica of Combinations) points out it "assists the water organ (Kidneys), reduces edema, treats coughing and rebellious Qi, and brightens the eyes."

These records reflect summaries of clinical practice from their respective eras and should not be viewed as direct conclusions of modern medicine.

2. Evolution of Pharmacological Understanding

Different TCM physicians have held slightly varying views on Chu Shi Zi:

Some emphasize its tonifying effects, viewing it as a gentle tonic for the Liver and Kidneys to boost essence and Qi, suitable for long-term weakness.
Others focus on its clearing and water-draining properties, utilizing it to clear Liver and Kidney deficiency-heat or to relieve edema.
Application is often adjusted based on the patient's constitution. For instance, if someone has a cold Spleen and Stomach, a practitioner might add warming herbs to prevent the astringent nature of Chu Shi Zi from affecting digestion. This highlights that it is not a "cure-all" and requires professional pattern differentiation (Bian Zheng).

Core Efficacies & Traditional Applications

Traditional Functions

Supplements the kidney, clears the liver, brightens the eyes, promotes urination. Apply to soreness and weakness of waist and knees, consumptive and bone-steaming, dizziness and blurred vision, corneal opacity, edema and swelling.

1. Primary Focus: Tonifying Liver and Kidney

The main traditional use of Chu Shi Zi (Paper Mulberry Fruit) is to nourish the Yin of the Liver and Kidneys while gently clearing away "deficiency-heat."

Common Symptoms: It is often used for signs of Liver and Kidney deficiency, such as a sore lower back and knees, dizziness, dry eyes, hot flashes, and night sweats.
Common Pairings: Practitioners frequently combine it with Gou Qi Zi (Goji Berry) and Nu Zhen Zi (Glossy Privet Fruit) to enhance its tonifying effects. If there is noticeable internal heat, it might be paired with Di Gu Pi (Wolfberry Bark).
Warning: People with a cold Spleen and Stomach or those who frequently experience loose stools should avoid using it on their own, as its slightly astringent nature can burden digestion.

2. Secondary Focus: Brightening the Eyes

In TCM, nourishing the Liver and Kidneys is a root-level method for improving vision, which is entirely different from just clearing "Liver fire."

Common Symptoms: It helps with dry eyes, blurred vision, and tearing up in the wind—often caused by long-term eye strain, staying up late, and depleting the Liver.
Common Pairings: It is usually paired with Ju Hua (Chrysanthemum) and Gou Qi Zi (Goji Berry) to both nourish the roots and clear the head and eyes.
Warning: If you have acute eye issues with redness, swelling, and sharp pain (which are "excess" heat conditions), do not use this herb, as it could worsen the symptoms.

3. Common Herb Pairing: The Synergy

A classic combination is Chu Shi Zi (Paper Mulberry Fruit) paired with Gou Qi Zi (Goji Berry).

The Synergy: Both herbs are sweet and neutral. While Chu Shi Zi tonifies while clearing deficiency-heat, Gou Qi Zi focuses deeply on nourishing essence and brightening the eyes. Together, they create a balanced synergy perfect for dizziness and dry eyes caused by deficiency.
Best For: This pairing requires a professional assessment. If you have significant internal heat or digestive issues, a practitioner will need to adjust the formula rather than relying on this standard pair.

Modern Research

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

1. Primary Chemical Components

Research has identified various components in Chu Shi Zi, including flavonoids, alkaloids, essential oils, and fatty acids. Flavonoids are currently the most extensively studied group.

In Vitro: Some flavonoid components demonstrate antioxidant activity.
Animal Studies: Extracts given to animal models have shown some potential in improving markers related to liver and kidney function.
Note: There is currently a lack of sufficient human clinical trials to establish definitive therapeutic conclusions.

2. Focus of Modern Pharmacological Research

Current research primarily focuses on its antioxidant properties and its potential to improve metabolic markers. Experimental observations suggest the flavonoids it contains may help scavenge free radicals in the body. However, more human studies are needed to confirm if these laboratory findings translate to human health benefits.

3. Limitations of Modern Research

Lab Results vs. Clinical Efficacy: Findings from test tubes (in vitro) or animal studies do not guarantee the same effects when humans consume the herb.
Extracts vs. Traditional Herbs: Modern research often uses highly concentrated extracts or isolated single compounds. These are completely different in dosage and form from the traditional raw herbal slices used in TCM and cannot be directly substituted.
Variability in Studies: Different studies use varying dosages and extraction methods, leading to different results. A single study's conclusion doesn't represent the whole picture.
Synergy vs. Single Component: Chu Shi Zi contains a complex mix of compounds that work together. The activity of one isolated component cannot fully represent the overall effect of the whole herb.

Comparing Similar Herbs

1. Similarities

Both Chu Shi Zi (Paper Mulberry Fruit) and Gou Qi Zi (Goji Berry) tonify the Liver and Kidneys and brighten the eyes. They are both traditionally used for dizziness and dry eyes and often appear in similar wellness routines or dietary therapies. Neither should be consumed in massive quantities long-term without guidance.

2. Core Differences

Nature: Chu Shi Zi is neutral, sweet, and slightly astringent; it tonifies while clearing heat without being too drying or too cold. Gou Qi Zi is also neutral and sweet but is a pure tonic without astringent or clearing properties.
Focus: Besides tonifying, Chu Shi Zi clears deficiency-heat and helps drain mild water retention (edema). Gou Qi Zi strictly focuses on deep nourishment and enriching Yin essence.
Action: Chu Shi Zi has a slightly consolidating (astringent) effect that helps manage excess heat without causing energy stagnation. Gou Qi Zi is much gentler, focusing purely on replenishing bodily fluids.
Ideal User: Chu Shi Zi is for those with Liver/Kidney deficiency plus signs of heat (like hot palms/soles or night sweats) or mild swelling in the legs. Gou Qi Zi is for pure deficiency, like dry eyes and blurred vision without obvious heat or swelling.
Avoid if: Skip Chu Shi Zi if you have a cold digestive system and loose stools. Skip Gou Qi Zi if you have "damp-heat" (often indicated by a bitter taste in the mouth and a thick tongue coating).

3. One-Sentence Summary

Chu Shi Zi (Paper Mulberry Fruit) is a dual-action herb that tonifies the Liver and Kidneys while clearing heat and fluids, whereas Gou Qi Zi (Goji Berry) is a pure, nourishing tonic focused entirely on restoring essence and vision.

Classical Formulas Containing Chu Shi Zi

Formulas vs. Single Herbs

Synergy is Key: A formula is a balanced team. The healing power comes from how the herbs interact, so a single herb cannot simply replicate a full formula's effects.
Holistic Balance: The exact dosage and combination in a formula affect the entire body. Never try to mix or alter these formulas at home based on internet articles.

Diet & Daily Home Use

1. Home Herbal Teas and Recipes

Recipe Recommendation: Chu Shi Zi and Gou Qi Zi Tea

Ingredients: Chu Shi Zi (Paper Mulberry Fruit) 3g, Gou Qi Zi (Goji Berry) 5g. (Ensure you buy medicinal-grade herbs, not just standard groceries).
Method: Rinse both herbs, place them in a mug, and steep with boiling water for 10 minutes. You can refill with hot water until the flavor fades.
Best For: Soothing dry eyes and mild dizziness from staying up late or excessive screen time.
Who Should Avoid It: Anyone with a cold stomach, chronic loose stools, or damp-heat (thick tongue coating).
Frequency: Drink 2 to 3 times a week. Do not consume it daily.

2. Decoction and Processing Differences

Processing: The raw form of Chu Shi Zi is standard and usually doesn't require special processing.
Home Boiling: When boiling, place Chu Shi Zi inside a small cheesecloth bag. Because the seeds are small, they will float and might not release their active ingredients properly if left loose. It can be boiled at the same time as your other herbs.
Note: Never guess dosages if you are switching between raw herbal slices and modern patent medicines (pills/extracts), as their concentrations are completely different.

3. Dosage and Cycle

Clinical Dose: Typically ranges from 6 to 12g in standard prescriptions.
Dietary Dose: When used in teas or soups at home, the dose should be much lower than the clinical amount, as the goal is gentle, daily support.
Usage Cycle: Do not use continuously for more than 2 weeks. If symptoms persist, consult a professional. Dosages must be strictly adjusted for children, the elderly, and pregnant women.

Contraindications & Safety Warnings

1. Who Should Avoid It

Digestive Issues: People with a cold Spleen and Stomach or chronic diarrhea should avoid it, as the astringent nature can upset digestion.
Pregnant & Nursing Women: There is not enough safety data for these groups; avoid use unless prescribed by a specialist.
Vulnerable Populations: Children and the elderly have sensitive systems and require professional guidance.
Organ Impairment: Anyone with liver or kidney dysfunction should get medical clearance before taking herbal supplements to avoid extra organ strain.
Allergies: If you are allergic to plants in the Moraceae family (like mulberries or figs), avoid this herb.

2. Drug Interactions and Diet

Western Medications: Chu Shi Zi may potentially interact with blood thinners, antihypertensives, and diabetes medications. If you are on these drugs, consult your doctor or pharmacist first.
Timing: Always leave a 1 to 2-hour gap between taking TCM herbs and Western medications to prevent absorption issues.

3. Adverse Reactions and Overdose Risks

Side Effects: Taking too much can lead to gastrointestinal discomfort, such as bloating and nausea.
Emergency Action: If you experience any severe discomfort, allergic reactions (like rashes or itching), continuous vomiting, breathing difficulties, or rapid worsening of symptoms, stop use immediately and seek emergency medical care.

Frequently Asked Questions About Chu Shi Zi

What is Chu Shi Zi? Are Gou Qi Zi and Sang Shen the same?

Official Chu Shi Zi (楮实子) is the dried ripe fruit of Broussonetia papyrifera. The pharmacopoeial name is Broussonetiae Fructus. It is also called paper-mulberry fruit. Gou Qi Zi is sweet and neutral: nourishes the Liver and Kidney, boosts essence and brightens the eyes. Sang Shen is sweet-sour and cold: nourishes yin, supplements Blood, generates fluid and moistens dryness. Write Chu Shi Zi. Use caution in Spleen-Stomach vacuity cold.

What are the TCM properties and traditional uses of Chu Shi Zi?

According to the Chinese Pharmacopoeia, Chu Shi Zi is sweet and cold, enters the Liver and Kidney channels, and acts to supplement the Kidney, clear the Liver, brighten the eyes and promote urination. It is used for Liver-Kidney insufficiency, sore weak waist and knees, vacuity-taxation steaming bone, dizziness and dim vision, eye films, and edema with fullness. Sweet, cold and clearing, it suits Liver-Kidney insufficiency with vacuity heat—not Spleen-Stomach vacuity cold or loose stool.

How do you choose Chu Shi Zi versus Gou Qi Zi? Can Sang Shen replace it?

Paper-mulberry fruit is cold, clears the Liver and also promotes urination. Lycium fruit is neutral and supplements essence and Blood while brightening the eyes. Mulberry fruit leans to nourishing yin, supplementing Blood and moistening dryness. They cannot replace one another by equal weight. Commercial paper-mulberry tea is not equal-weight pieces.

What is the usual dosage? Can it be drunk daily as an eye tea?

The pharmacopoeial decoction dose is 6–12 g. It is not a four-season “paper-mulberry eye tea.” Spleen-Stomach vacuity cold only loosens further as it cools. Dim vision and edema need a practitioner to name a short course; they do not replace eye or medical assessment.

What are the contraindications? Can it be used in pregnancy?

Use caution in Spleen-Stomach vacuity cold and loose stool. Pregnancy needs a practitioner’s assessment. Stop if diarrhea or cold epigastric pain appears. Sudden loss of vision and edema with shortness of breath need medical care.

Can Chu Shi Zi supplement the Kidney, clear the Liver, brighten the eyes and promote urination?

It can help dim vision with eye films and sore weak waist and knees from Liver-Kidney insufficiency. Dim vision is often joined with lycium, chrysanthemum and cassia seed in an eye-brightening type formula. Edema may join poria and alisma after pattern differentiation. It supplements the Kidney, clears the Liver, brightens the eyes and promotes urination—not a specific for every eye disease or every edema.

Can Chu Shi Zi be drunk daily as an eye, Kidney or water tea?

Liver-Kidney insufficiency with vacuity heat may enter a short formula; Spleen-Stomach vacuity cold only loosens further as it cools. “Paper mulberry must brighten the eyes” does not replace eye assessment. Supplementing the Kidney, clearing the Liver, brightening the eyes and promoting urination should name 6–12 g.

How do you choose among Chu Shi Zi, Gou Qi Zi, Sang Shen, Jue Ming Zi and Che Qian Zi?

Paper-mulberry fruit is sweet-cold: supplements the Kidney, clears the Liver, brightens the eyes and promotes urination—dim vision with films and edema. Lycium fruit is sweet and neutral: nourishes the Liver and Kidney, boosts essence and brightens the eyes—Liver-Kidney yin vacuity with dim vision. Mulberry fruit is sweet-sour and cold: nourishes yin, supplements Blood, generates fluid and moistens dryness—insufficiency of yin and Blood. Cassia seed is sweet-bitter-salty and slightly cold: clears heat, brightens the eyes, moistens the intestines and frees the stool—Liver-heat red eyes and constipation. Plantago seed is sweet-cold: clears heat, promotes urination, percolates dampness, stops diarrhea, brightens the eyes and dispels phlegm—damp-heat strangury. Vacuity-heat dim vision favors Chu Shi Zi; insufficiency of essence and Blood favors Gou Qi Zi; insufficiency of yin and Blood favors Sang Shen; Liver heat with constipation favors Jue Ming Zi; heat strangury favors Che Qian Zi. They may be paired after pattern differentiation; Spleen-Stomach vacuity cold forbids large Chu Shi Zi and Jue Ming Zi.

Which herbs is Chu Shi Zi combined with? What are the representative formulas?

Dim vision with films joins lycium, chrysanthemum and cassia seed in an eye-brightening type formula. Sore weak waist and knees may join achyranthes and eucommia after pattern differentiation. Write Chu Shi Zi 6–12 g; do not replace clearing the Liver and promoting urination with lycium fruit by equal weight.

How do you choose and store Chu Shi Zi?

Choose nearly spherical or ovoid fruits, reddish brown, netted, ridged on one side, hard and brittle, a whitish oily endosperm, a faint odor and a bland taste. Lots with much persistent calyx, mold, moths or a rancid odor are discarded. Store ventilated and dry. Buy pharmacopoeial Chu Shi Zi; do not replace supplementing the Kidney, clearing the Liver, brightening the eyes and promoting urination with lycium fruit or mulberry fruit by equal weight.

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.