Herb Rhizome (根茎 gēn jīng)

Gu Sui Bu

Drynaria rhizome · 骨碎补

Drynaria fortunei (Kunze) J. Sm. · Rhizoma Drynariae

Also known as: Monkey Ginger, Hóu Jiāng (猴姜), Shēn Jiāng (申姜),

Gu Sui Bu (Drynaria rhizome) plant

Images shown are for educational purposes only

Gu Sui Bu, sometimes called 'the bone mender,' is one of Chinese medicine's most important herbs for healing fractures and strengthening bones. It warms and supports the Kidneys, which in TCM govern bone health, making it useful for lower back pain, loose teeth, tinnitus, and weak knees. It is also applied externally for patchy hair loss.

Category Blood-invigorating and stasis-dispelling herbs (活血化瘀药) Blood-invigorating and trauma-healing herbs (活血疗伤药)
Therapeutic focus Bone and Joint Health Fracture recovery Oral and Dental Health Ear and Hearing Health Hair loss (topical)

TCM Properties

Temperature

Warm

Taste

Bitter (苦 kǔ)

Channels entered

Liver, Kidneys

Parts used

Rhizome (根茎 gēn jīng)

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Educational content • Consult qualified TCM practitioners for diagnosis and treatment

What This Herb Does

Every herb has a specific set of actions — here's what Gu Sui Bu does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Gu Sui Bu is primarily used to support these areas of health:

Bone and Joint Health Fracture recovery Oral and Dental Health Ear and Hearing Health Hair loss (topical)

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Gu Sui Bu performs to restore balance in the body:

Treats Traumatic Injuries Benefits the Kidneys and Strengthens the Bones Invigorates Blood and Dispels Stasis Strengthens the Sinews and Bones Dispels Wind-Heat from the Skin

How these actions work

'Heals injuries and stops pain' means Gǔ Suì Bǔ directly treats traumatic injuries, especially bone fractures and sprains. Its bitter taste and warm nature allow it to move stagnant Blood away from the injury site while its Kidney-strengthening action supports bone repair. This is the herb's signature action and the origin of its name, which literally means 'mender of shattered bones.' It is a staple herb in orthopedic formulas for fractures, dislocations, and soft tissue injuries, used both internally and as a topical application.

'Tonifies the Kidneys and strengthens bones' reflects the fact that in TCM, the Kidneys govern the bones. When Kidney function is weak, bones become fragile, teeth loosen, the lower back aches, and hearing declines. Gǔ Suì Bǔ's warm nature gently warms Kidney Yang, which supports bone density and structural integrity. This action is used for conditions like chronic lower back pain, weak knees, loose teeth, tinnitus, hearing loss, and prolonged diarrhea due to Kidney weakness.

'Invigorates Blood and disperses stasis' means the herb promotes blood circulation and breaks up accumulations of old, stagnant blood. This is why it reduces swelling and pain after trauma. Classical texts note it can both 'break Blood' and 'stop Blood,' meaning it clears stagnation without causing excessive bleeding.

'Dispels Wind and eliminates skin patches (external use)' refers to the topical application of Gǔ Suì Bǔ soaked in alcohol, which is used to treat patchy hair loss (alopecia areata) and vitiligo. The herb's stimulating, warming properties are thought to increase local blood flow to the affected skin areas.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Gu Sui Bu is used to help correct these specific patterns.

Why Gu Sui Bu addresses this pattern

Gǔ Suì Bǔ is bitter and warm, entering the Kidney and Liver channels. Its warm nature directly addresses the cold and weakness characteristic of Kidney Yang Deficiency. By warming Kidney Yang, it strengthens the bones and sinews (since the Kidneys govern the bones), which is why it treats the lower back pain, weak knees, loose teeth, tinnitus, and hearing loss that arise when Kidney Yang fails to nourish the skeletal system. Its ability to warm the Kidneys also addresses the chronic diarrhea that results when Kidney Yang cannot support the Spleen's digestive function (known as 'Kidney failing to warm the Spleen').

A practitioner would look for one or more of these signs

Lower Back Pain

Chronic, dull lower back pain worse with cold

Tinnitus

Low-pitched, persistent tinnitus from Kidney deficiency

Loose Teeth

Teeth loosening without gum inflammation

Hearing Loss

Gradual hearing decline

Chronic Diarrhea

Early morning diarrhea from Kidney-Spleen Yang failure

Commonly Used For

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

Arises from: Kidney Yang Deficiency Spleen and Kidney Qi Deficiency

TCM Interpretation

TCM understands osteoporosis through the principle that 'the Kidneys govern the bones and produce marrow.' Bone density depends on the Kidneys' ability to supply nourishment to the skeletal system. As people age, Kidney essence (Jing) naturally declines, and Kidney Yang weakens. This leads to what classical texts call 'bone withering' (骨痿). Factors like overwork, chronic illness, and cold exposure accelerate this decline. The condition is understood as primarily a deficiency pattern rooted in the Kidneys, often with secondary involvement of the Liver (which governs the sinews supporting the bones) and the Spleen (which generates the Blood and Qi needed for nourishment).

Why Gu Sui Bu Helps

Gǔ Suì Bǔ directly addresses the Kidney root of osteoporosis through its warm nature and Kidney channel affinity. By warming Kidney Yang, it supports the Kidneys' bone-governing function. Modern research has confirmed that total flavonoids from Drynaria rhizome (particularly naringin) can promote osteoblast proliferation and inhibit osteoclast activity, effectively stimulating bone formation while reducing bone breakdown. The herb's Blood-invigorating action also helps ensure that nutrients reach the bone tissue. This dual mechanism of tonifying the Kidneys while actively promoting bone metabolism makes it well suited for osteoporosis treatment.

Also commonly used for

Lower Back Pain

Especially when due to Kidney deficiency

Loose Teeth

Periodontal disease with tooth loosening

Alopecia

Topical use for patchy hair loss (alopecia areata)

Trauma

Sprains, dislocations, soft tissue injuries

Chronic Diarrhea

Kidney-deficiency type early-morning diarrhea

Vitiligo

External application for depigmented skin patches

Osteoarthritis

Degenerative joint disease

Herb Properties

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

Temperature

Warm

Taste

Bitter (苦 kǔ)

Channels Entered

Liver Kidneys

Parts Used

Rhizome (根茎 gēn jīng)

Dosage & Preparation

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

Standard dosage

10-15g

Maximum dosage

Up to 20g in standard decoction. Do not exceed this range without practitioner supervision. Doses around 100g have caused toxic reactions.

Dosage notes

Use 10-15g for standard decoction for internal conditions such as Kidney deficiency with lower back pain, tinnitus, loose teeth, or chronic diarrhoea. For acute traumatic injury and fracture, the dosage may be increased toward 15-20g and is often combined with other trauma herbs such as Xu Duan, Zi Ran Tong, and Mo Yao. For external use (alopecia areata, vitiligo), soak the herb in alcohol and apply topically in appropriate amounts. The processed form (sand-fried, 烫骨碎补) is preferred for internal Kidney-tonifying purposes, as processing reduces bitterness and enhances warming, supplementing action. Fresh or raw herb may be used for external poultices on fracture sites.

Preparation

The rhizome surface is covered in dense, irritating scale-like hairs that must be removed before use. The standard modern processing method is sand-frying (砂烫): heat sand in a wok until fluid, add the sliced rhizome, stir-fry until the pieces puff up and the hairs become scorched, then sift out the sand and rub off the burnt hairs after cooling. This sand-frying reduces gastric irritation, moderates the bitter flavour, and strengthens the warming, Kidney-supplementing action. An older method from the Lei Gong Pao Zhi Lun involves scraping off the hairs with a metal knife, slicing finely, mixing with honey, and steaming in a willow-wood steamer for a full day before drying. No special decoction handling (such as decocting first or adding late) is required.

Processing Methods

In TCM, the same herb can be prepared in different ways to change its effects — here's how processing alters what Gu Sui Bu does

Processing method

Sand-fried (砂烫): Clean Gǔ Suì Bǔ slices are placed in pre-heated sand and stir-fried over strong heat until the pieces swell and puff up. They are then removed, sieved to remove the sand, cooled, and the burnt surface hairs are knocked off.

How it changes properties

Sand-frying reduces the raw herb's bitter, stasis-breaking quality while enhancing its warming, tonifying nature. The processed form becomes lighter, more porous, and easier to extract. Its emphasis shifts from invigorating Blood toward tonifying the Kidneys and strengthening bones. Naringin content actually increases after processing, improving its bone-protective activity.

When to use this form

The sand-fried form is the standard clinical form and is preferred for internal use in Kidney deficiency conditions such as chronic lower back pain, weak knees, loose teeth, tinnitus, and hearing loss. The raw form is more commonly used for topical applications or when stronger Blood-invigorating action is needed for acute trauma.

Common Herb Pairs

These ingredients are traditionally combined with Gu Sui Bu for enhanced therapeutic effect

Bu Gu Zhi
Bu Gu Zhi 1:1 to 1:3 (Gǔ Suì Bǔ : Bǔ Gǔ Zhī)

Both herbs warm Kidney Yang and strengthen the skeletal system, but through complementary mechanisms. Gǔ Suì Bǔ focuses on strengthening bones and invigorating Blood in the bone tissue, while Bǔ Gǔ Zhī (Psoralea fruit) warms the Kidney gate fire and also warms the Spleen to stop diarrhea. Together they produce a stronger Kidney-warming, bone-strengthening effect than either alone, and simultaneously address both the skeletal and digestive consequences of Kidney Yang Deficiency.

When to use: Kidney Yang Deficiency presenting with lower back pain, weak knees, loose teeth, or early-morning diarrhea. Also used in bone-healing formulas when the patient has underlying Kidney weakness.

Zi
Zi Ran Tong 1:1

Gǔ Suì Bǔ invigorates Blood and tonifies the Kidneys to support bone regeneration, while Zì Rán Tóng (natural copper / Pyritum) specifically excels at joining fractured bone and dispersing stasis from the injury site. Together they form one of the most classic pairs in Chinese orthopedic medicine, combining bone-mending, stasis-clearing, and pain-relieving actions.

When to use: Bone fractures with localized swelling, bruising, and pain. Used during the acute and recovery phases of fracture healing.

Xu Duan
Xu Duan 1:1

Both herbs tonify the Liver and Kidneys, strengthen bones and sinews, and treat traumatic injuries. Xù Duàn (Dipsacus root) has a milder, more nourishing quality and also promotes Blood circulation without being as strongly stasis-breaking. Together they reinforce each other's bone-healing and Kidney-tonifying actions, producing a well-rounded formula base for both traumatic injury and chronic Kidney deficiency affecting the bones.

When to use: Fractures during the later healing phase, chronic lower back pain from Kidney deficiency, or tendon and ligament injuries alongside bone damage.

Niu Xi
Niu Xi 1:1

Gǔ Suì Bǔ tonifies the Kidneys and strengthens bones from above, while Niú Xī (Achyranthes root) guides the formula's actions downward to the lower back and knees, invigorates Blood, and strengthens sinews and bones. The combination targets Kidney deficiency manifesting in the lower body, such as lower back pain and weak legs.

When to use: Kidney-deficiency lower back pain and knee weakness, or lower limb pain after injury. Also used when loose teeth or gum problems accompany lower body weakness.

Comparable Ingredients

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

Bu Gu Zhi
Gu Sui Bu vs Bu Gu Zhi

Both tonify Kidney Yang and strengthen bones, but Bǔ Gǔ Zhī (Psoralea fruit) is more specialized for warming the Kidney gate fire and Spleen Yang. It primarily treats early-morning diarrhea, impotence, and urinary frequency, and lacks Gǔ Suì Bǔ's strong Blood-invigorating and fracture-healing actions. Choose Gǔ Suì Bǔ when there is traumatic injury with Blood stasis, and Bǔ Gǔ Zhī when the focus is on warming Kidney-Spleen Yang without injury.

Xu Duan
Gu Sui Bu vs Xu Duan

Both tonify the Liver and Kidneys, strengthen bones, and treat traumatic injuries. However, Xù Duàn is milder and more nourishing, with an additional ability to calm the fetus (used in pregnancy), which Gǔ Suì Bǔ cannot do (it is contraindicated in pregnancy). Gǔ Suì Bǔ is stronger at invigorating Blood and breaking stasis, making it better for acute fractures with significant swelling, while Xù Duàn is preferred when gentler bone and sinew support is needed.

Zi
Gu Sui Bu vs Zi Ran Tong

Both are key orthopedic herbs for fractures. Zì Rán Tóng (natural copper) is more narrowly focused on joining bone and dispersing stasis at fracture sites, with minimal tonifying action. Gǔ Suì Bǔ has a broader profile: it invigorates Blood but also tonifies Kidney Yang and strengthens bones long-term. For simple fracture repair, Zì Rán Tóng is more direct; for fractures in patients with underlying Kidney deficiency or for long-term bone strengthening, Gǔ Suì Bǔ is preferred.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Gu Sui Bu

Multiple fern species are used regionally as Gu Sui Bu substitutes, which can significantly affect therapeutic outcomes. The Chinese Pharmacopoeia standard species is Drynaria fortunei (槲蕨). Common substitutes include: Drynaria baronii (中华槲蕨, used in some southern provinces), Pseudodrynaria coronans (大叶骨碎补, Davalliaceae family, used in Guangxi and Guangdong), and Davallia species (海州骨碎补). The authentic Drynaria fortunei rhizome is distinguished by its flat, elongated shape with dense soft brown scales, reddish-brown cross-section with yellow vascular bundles in a ring, and mild, slightly astringent taste. The large-leaf substitute (大叶骨碎补) has a more cylindrical, twisted shape, harder texture, and two distinctly larger crescent-shaped vascular bundles in the centre of the cross-section. Some of these substitutes have not been verified for equivalent therapeutic efficacy and are not included in the Pharmacopoeia, posing potential safety and effectiveness concerns.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Gu Sui Bu

Non-toxic

The Kai Bao Ben Cao classifies Gu Sui Bu as 'non-toxic' (无毒), and the Chinese Pharmacopoeia does not list it among toxic herbs. At standard dosages (10-20g), it is generally safe with no significant adverse effects reported from long-term use. However, massive overdoses (around 100g in a single decoction) have caused toxicity, with symptoms including dry mouth, excessive talking, feelings of fear, palpitations, chest tightness, progressing to mental confusion, incoherent speech, and alternating euphoria and weeping. The unprocessed rhizome retains irritating surface hairs (scales) that can stimulate the gastrointestinal tract and cause nausea and vomiting. Proper processing (sand-frying to puff the herb and removing the hairs) eliminates this irritation and enhances therapeutic potency.

Contraindications

Situations where Gu Sui Bu should not be used or requires extra caution

Caution

Yin deficiency with internal Heat (阴虚内热). Gu Sui Bu is warm in nature and can further damage Yin and intensify Heat in those who already have Yin deficiency with Heat signs.

Caution

Blood deficiency with Wind-Dryness (血虚风燥) or Blood deficiency with Fire (血虚有火). Classical sources such as the Ben Cao Hui Yan explicitly prohibit use in these conditions, as the herb's warming and Blood-moving properties can worsen dryness and agitation.

Caution

Absence of Blood stasis (无瘀血者). When there is no actual Blood stasis, the herb's Blood-invigorating action is unnecessary and may cause harm by moving Blood inappropriately.

Caution

Should not be used together with drying, Wind-dispersing (风燥) medicinals, as noted in the Ben Cao Jing Shu, since these can compound drying effects.

Avoid

Excessive dosage (above 20g in decoction). Large doses, particularly around 100g, have caused toxicity with symptoms including dry mouth, excessive talking, fearfulness, palpitations, chest tightness, mental confusion, and incoherent speech.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Use with caution during pregnancy. Gu Sui Bu has significant Blood-invigorating and Blood-breaking properties, which could theoretically stimulate uterine contractions or promote excessive Blood movement, potentially disturbing the fetus. While it is not listed among the strictly prohibited pregnancy herbs in classical texts, its strong ability to move Blood warrants careful evaluation. It should only be used during pregnancy under direct practitioner supervision when the benefit clearly outweighs the risk, such as for acute fracture management.

Breastfeeding

No specific classical or modern contraindications for breastfeeding have been documented. However, given its warming nature and Blood-moving properties, caution is advised. The herb's active flavonoid compounds (such as naringin) may potentially transfer through breast milk, though this has not been formally studied. Use during breastfeeding should be kept to standard dosages and under practitioner guidance. If the nursing infant shows any signs of digestive upset or irritability, discontinue use.

Children

Gu Sui Bu may be used in children for fracture healing and bone injuries, but dosage should be reduced proportionally based on age and body weight (typically one-third to one-half of the adult dose for children over 6 years). It is not commonly used in very young children (under 3 years) due to limited clinical data in this age group. The warming, Blood-moving nature of the herb requires particular care in children, who tend to have immature digestive systems. The processed (sand-fried) form is preferred over the raw herb to reduce gastrointestinal irritation. Always use under qualified practitioner supervision.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Gu Sui Bu

Aminoglycoside antibiotics (streptomycin, kanamycin): Clinical observations have shown that Gu Sui Bu decoction can reduce the ototoxic side effects of aminoglycoside antibiotics. In a clinical report of 21 cases, Gu Sui Bu decoction taken concurrently with streptomycin mitigated symptoms of headache, dizziness, lip and tongue numbness, and showed some benefit for tinnitus and deafness. This suggests a protective interaction rather than a harmful one, but it should be used under medical supervision, as it cannot fully prevent progression of drug-induced hearing loss after the antibiotic is stopped.

Other interactions: No well-documented harmful drug interactions have been reported in peer-reviewed literature. However, given the herb's Blood-invigorating properties, theoretical caution is warranted when combining with anticoagulant or antiplatelet medications (such as warfarin or aspirin), as it may have additive effects on bleeding risk. Patients on such medications should inform their prescribing physician.

Dietary Advice

Foods and dietary considerations when taking Gu Sui Bu

Classical sources (De Pei Ben Cao) advise avoiding lamb meat (羊肉), lamb blood (羊血), and rapeseed greens (芸薹菜, a Brassica vegetable) while taking Gu Sui Bu, as these were considered incompatible foods. When using the herb for Kidney-tonifying purposes, it is helpful to include warm, nourishing foods that support the Kidney such as black beans, walnuts, and bone broth, and to avoid excessive cold, raw foods that can impair the warming therapeutic effect.

Botanical Description

Physical characteristics and morphology of the Gu Sui Bu source plant

Gu Sui Bu is the dried rhizome of Drynaria fortunei (Kunze) J. Sm. (also known as Drynaria roosii), a perennial epiphytic fern in the family Polypodiaceae, commonly called a basket fern. The plant grows 20 to 40 cm tall and attaches itself to tree trunks, rock faces, cliff walls, and sometimes old buildings, typically in shaded, moist environments at elevations of 100 to 1,800 metres.

The rhizome is fleshy, stout, and creeping, densely covered with brown, linear lance-shaped scales that feel soft and furry. The plant produces two distinct frond types: sterile "nest" fronds that are thick, leathery, reddish-brown, ovate, sessile, 5 to 6.5 cm long, with shallowly lobed margins resembling oak leaves; and larger fertile fronds that are green, oblong, 20 to 37 cm long and 8 to 18.5 cm wide, deeply lobed with 6 to 15 pairs of broadly lance-shaped segments. Round, yellow-brown spore clusters (sori) are arranged in 2 to 4 rows on each side of the midrib on the undersides of fertile fronds.

Sourcing & Harvesting

Where Gu Sui Bu is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Can be harvested year-round, but traditionally collected in winter and spring. The rhizome is dug up, cleaned of leaves and soil, and dried or steamed before drying, then singed to remove the surface hairs.

Primary growing regions

Gu Sui Bu is widely distributed across subtropical China, south of the Yangtze River. The traditional 'terroir' regions (道地产区, dào dì yào cái) producing the highest quality herb are Hubei, Jiangxi, and Sichuan provinces. Wild populations are also found in Zhejiang, Fujian, Guangdong, Guangxi, Guizhou, Hunan, Yunnan, and Anhui. The plant also grows in Thailand, Laos, and Vietnam. The major commercial drug sources currently come from Hubei, Sichuan, Guangxi, Guizhou, Hunan, and Yunnan.

Quality indicators

Good quality Gu Sui Bu rhizome is flat, elongated, slightly curved with branches, 5 to 15 cm long, 1 to 1.5 cm wide, and 0.2 to 0.5 cm thick. The surface should be densely covered with deep brown to dark brown small scale-like hairs that feel soft and furry. After fire-singeing processing, these scales turn brown-black. Both sides and the upper surface should show raised or depressed round leaf scars. The herb should be light in weight, crisp in texture, and easy to snap. The cross-section should be reddish-brown with yellow vascular bundle dots arranged in a ring pattern. The odour should be faint, and the taste mild with slight astringency. For sand-fried (processed) herb, the pieces should be puffed up, light, loose-textured, and yellow-brown to deep brown with scales removed.

Classical Texts

Key passages from the classical Chinese medical texts that describe Gu Sui Bu and its therapeutic uses

Kai Bao Ben Cao (《开宝本草》, Song Dynasty)

Original: 「味苦，温，无毒。」「主破血，止血，补伤折。」

Translation: "Bitter in flavour, warm in nature, non-toxic." "Breaks up Blood [stasis], stops bleeding, and mends injuries and fractures."

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

Original: 「骨碎补，本名猴姜，开元皇帝以其主伤折，补骨碎，故命此名。」

Translation: "Gu Sui Bu was originally called 'Monkey Ginger.' Emperor Kaiyuan renamed it because it treats fractures and mends shattered bones, hence the name 'Bone-Mender.'"

Yao Xing Lun (《药性论》, Tang Dynasty)

Original: 「主骨中毒气，风血疼痛，五劳六极，口手不收，上热下冷。」

Translation: "Treats toxic Qi in the bones, Wind-Blood pain, the five types of exhaustion and six extremes of taxation, loss of control in mouth and hands, and the pattern of Heat above with Cold below."

Ben Cao Gang Mu (《本草纲目》, Ming Dynasty, Li Shizhen)

Original: 「骨碎补，足少阴药也。故能入骨，治牙，及久泄痢。」

Translation: "Gu Sui Bu is a medicinal of the Foot Shaoyin [Kidney] channel. Therefore it can enter the bones, treat dental problems, and address chronic diarrhoea and dysentery."

Ben Jing Xu Shu (《本经续疏》)

Original: 「骨碎补主破血、止血、补伤折，言能不使瘀结者留滞，不使流动者妄行，而补苴伤折，如未尝伤折也。」

Translation: "Gu Sui Bu breaks up Blood [stasis], stops bleeding, and mends fractures. This means it prevents stagnant clots from lingering, prevents freely moving Blood from flowing recklessly, and repairs injuries so thoroughly it is as if they never occurred."

Historical Context

The history and evolution of Gu Sui Bu's use in Chinese medicine over the centuries

The herb was originally known as Hou Jiang (猴姜, "Monkey Ginger") because its rhizome resembles ginger and the plant grows in places frequented by monkeys, clinging to rock faces and tree trunks. According to Chen Cangqi's Ben Cao Shi Yi (Tang Dynasty), Emperor Xuanzong of Tang (reign era Kaiyuan, 713-741 CE) personally renamed it Gu Sui Bu (骨碎补, "Bone-Mender") because of its remarkable ability to treat fractures and repair shattered bones. This imperial naming elevated the herb's status and cemented its identity as a key trauma medicine.

Li Shizhen in the Ben Cao Gang Mu (Ming Dynasty) recorded a famous case: a regional official's son suffered from chronic diarrhoea that many doctors could not cure. Li Shizhen treated him by grinding Gu Sui Bu to powder, placing it inside a pig kidney, and having the patient eat it after slow-roasting. The diarrhoea stopped immediately. Li Shizhen explained this through the principle that the Kidney governs both bones and the lower orifices: chronic diarrhoea belongs to Kidney deficiency and should not be treated solely through the Spleen and Stomach. This case became a classic teaching example of the herb's Kidney-tonifying function beyond its trauma applications.

Over the centuries, the herb's documented uses evolved considerably. The earliest Pharmacopoeia entries (1963) focused on its Kidney-supplementing, Blood-breaking, and Blood-stopping actions. By the 1977 edition, its external use for alopecia areata was added. From 1985 onward, the Chinese Pharmacopoeia standardized its indications as "tonifying the Kidney to strengthen bones, mending injuries and stopping pain," with external application for alopecia areata and vitiligo, reflecting its broadening clinical scope.

Modern Research

5 published studies investigating the pharmacological effects or clinical outcomes of Gu Sui Bu

1

Drynaria fortunei-derived total flavonoid fraction and isolated compounds exert oestrogen-like protective effects in bone (In vitro/In vivo study, 2013)

Jeong JC, Lee JW, Yoon CH, Kim HM, Kim CH. J Ethnopharmacol. 2004;95(2-3):401-405.

This study investigated the bone-protective mechanisms of Drynaria fortunei. The total flavonoid fraction and isolated compounds were shown to exert estrogen-like anabolic effects on bone, suggesting a mechanism for its traditional use in treating fractures and osteoporosis. The findings support Gu Sui Bu's role in promoting bone formation through estrogen receptor-related pathways.

PubMed
2

Drynaria fortunei J. Sm. improves the bone mass of ovariectomized rats through osteocalcin-involved endochondral ossification (Preclinical study, 2014)

Lee YE, Liu HC, Lin YL, Liu SH, Yang RS, Chen RM. J Ethnopharmacol. 2014;158 Pt A:94-101.

In ovariectomized rats (a model for postmenopausal osteoporosis), Drynaria fortunei extract improved bone mass through mechanisms involving osteocalcin and endochondral bone formation. The study provides preclinical evidence for the herb's traditional use in strengthening bones weakened by hormone deficiency.

3

Drynaria fortunei improves lipid profiles of elderly patients with postmenopausal osteoporosis via regulation of Notch1-NLRP3 inflammasome-mediated inflammation (RCT, 2021)

Li Y, Li Z, Chen G, Luo Z, Liu Y, et al. Evid Based Complement Alternat Med. 2021.

In this randomized controlled trial, 80 elderly female patients with concurrent postmenopausal osteoporosis and hyperlipidemia were treated with Drynaria fortunei preparations. The herb improved plasma lipid profiles and bone mineral density, with mechanisms linked to reduced inflammatory signaling through the Notch1-NLRP3 inflammasome pathway. This is one of the few clinical trials directly evaluating Gu Sui Bu in human patients.

PubMed
4

Gu Sui Bu (Drynaria fortunei J. Sm.) antagonizes glucocorticoid-induced mineralization reduction in zebrafish larvae (Preclinical study, 2022)

J Ethnopharmacol. 2022.

Using an in vivo zebrafish model, this study demonstrated that Gu Sui Bu extract significantly reversed dexamethasone-induced bone mineralization delay. The herb enhanced osteoblast activity by increasing expression of collagen I, osteopontin, and osteonectin, while repressing bone resorption by decreasing matrix metalloproteinase expression. These findings support its potential for treating glucocorticoid-induced osteoporosis.

PubMed
5

A study of Drynaria fortunei in modulation of BMP-2 signalling by bone tissue engineering (In vitro/In vivo study, 2020)

Huang ST, Chang CC, Pang JS, et al. J Formos Med Assoc. 2020.

This study examined how Gu Sui Bu and its marker compound naringin modulate bone morphogenetic protein (BMP-2) signalling. The herb acted as a subtle BMP modulator, and naringin-containing scaffolds implanted into rabbit calvarial defects significantly enhanced bone regeneration in vivo, supporting its application in bone tissue engineering.

PubMed

Research on individual TCM herbs is growing but still limited by Western clinical trial standards. These studies provide emerging evidence and should be considered alongside practitioner expertise.