GB-39 (Xuan Zhong) Suspended Bell, Suspended Time

What does GB-39 Xuan Zhong do?

Xuan Zhong GB-39 is the Hui-Meeting (influential) point of the Marrow — one of the eight points each of which governs a single tissue or category throughout the whole body — and that classification is the key to everything else about it. It sits on the Gall Bladder channel of Foot Shao Yang three cun above the ankle, and because marrow in Chinese medicine means the substance filling the bones and the brain alike, its recorded reach extends from the bones and the neck to the head.

• Benefits the marrow and the bones — the Hui-Meeting action and the defining one. It is chosen for weakness, softness or disorder of the bones anywhere in the body, and in the classical management of what the tradition calls bone atrophy.
• Benefits the neck — the single most consistently recorded local-distal use, and an association old enough that it is one of the first things said about the point. A neck that will not turn, an acutely stiff nape, and pain across the top of the shoulders all draw GB-39.
• Dispels wind-damp and opens the channel — for the aching, heavy, obstructed limbs the tradition attributes to wind-damp, and for weakness and wasting of the lower leg.
• Clears Gall Bladder fire — recorded for one-sided headache, bitter taste, red eyes, tinnitus and hypochondriac pain, following the Shao Yang channel up the side of the body to the head.
• Activates the channel and alleviates pain — the local action along the lateral lower leg, ankle and foot.
• Nourishes the Sea of Marrow indirectly — because the brain is the Sea of Marrow in Chinese physiology, the Hui-Meeting classification is the traditional rationale for the point's recorded use in dizziness, poor memory and the sequelae of windstroke. This is a theoretical link, and it should be read as such.

Source: Sacred Lotus sources & references (channel and Hui-Meeting classification; existing action record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 456); Chinese Acupuncture & Moxibustion (p. 220); Hui-Meeting point scheme per the Nan Jing (Classic of Difficulties), Difficulty 45; cross-referenced against multiple online sources.

What is GB-39 Xuan Zhong used for?

Xuan Zhong GB-39 is used above all for the neck and for disorders of the bones, and locally for the lower leg and ankle. The indications carried in Sacred Lotus sources & references are apoplexy and hemiplegia, pain of the neck, abdominal distension, hypochondriac pain, muscular atrophy of the lower limbs, spastic pain of the leg and beriberi; the standard reference literature sets them out more fully below. These describe traditional use, not proven treatment.

• Rigidity and pain of the neck; inability to turn the head
• Acute stiff neck
• Windstroke (apoplexy), hemiplegia and its sequelae
• Weakness, wasting and atrophy of the lower limbs
• Spastic or cramping pain of the leg and calf
• Pain and swelling of the ankle and lateral lower leg
• Sciatica and pain along the lateral aspect of the leg
• One-sided headache and migraine along the Gall Bladder channel
• Dizziness and tinnitus
• Pain in the hypochondrium and the ribs
• Abdominal distension and fullness
• Bitter taste in the mouth and sore throat
• Nosebleed (epistaxis)
• Beriberi (recorded in the classical sources)
• Haemorrhoids and rectal disorders recorded in the older literature
• Weakness or softness of the bones; disorders attributed to depleted marrow

Source: Sacred Lotus sources & references (existing indication record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 456); Chinese Acupuncture & Moxibustion (p. 220).

Where is GB-39 Xuan Zhong, and how is it used in practice?

Xuan Zhong sits on the outer side of the lower leg, three cun above the tip of the outer ankle bone, against the fibula — the slender outer bone of the calf. Three cun is roughly a hand's breadth, so the point falls about four finger-widths above the ankle prominence. It is the mirror image, on the outside of the leg, of San Yin Jiao SP-06 three cun above the inner ankle bone, and that symmetry is used deliberately: the two are the yang and yin partners of the same level, and have been studied together as a test of whether points really do have distinct effects.

Discrepancy flagged — which side of the fibula? Our own two location records differ, and the difference is real rather than a matter of wording. One places the point on the anterior border of the fibula; the other places it between the posterior border of the fibula and the tendons of peroneus longus and brevis. Both of our records are retained here unchanged. This is not our error: it is a long-standing disagreement in the field. A review at the Beijing University of Chinese Medicine traced the location of Xuanzhong through the principal ancient acupuncture texts, through the post-1949 university textbooks, through the national standards and through the more influential modern works, found the descriptions genuinely divergent, analysed when and why the divergence arose, and concluded that the point should be located three cun above the lateral malleolus between the anterior crest of the tibia and the anterior edge of the fibula (Zhen Ci Yan Jiu 2021;46(1):73–5, PMID 33559430, DOI 10.13702/j.1000-0607.200282). That supports the anterior description carried in one of our records. We are not resolving the conflict on one paper's authority; both records stand and the disagreement is disclosed.

Which points is GB-39 combined with?

• For a stiff or painful neck — the classical distal choice, used with Feng Chi GB-20 and Jian Jing GB-21 locally, with Hou Xi SI-03, and with the extra point Luo Zhen on the back of the hand, which is held here and is the other great point for a neck that has locked overnight.
• With Yang Ling Quan GB-34 — both are Hui-Meeting points and both sit on the lateral lower leg: GB-34 governs the sinews, GB-39 the marrow. They are used together where soft tissue and bone are both implicated, and this pairing is the most characteristic combination on the channel.
• For windstroke and hemiplegia — with Zu San Li ST-36 on the front of the same leg. This pairing has been trialled: a three-centre randomised controlled study in 160 patients with ischaemic stroke added acupuncture at Zu San Li ST-36 and Xuanzhong GB-39 to routine treatment and reported improvement in transcranial Doppler measures of cerebral blood flow against the control group (Zhongguo Zhen Jiu 2006;26(12):851–3, PMID 17313004).
• For marrow and bone — with Da Zhu BL-11, the Hui-Meeting point of the Bones, and with Shen Shu BL-23 and Tai Xi KI-03, on the classical reasoning that the Kidneys govern the bones and produce marrow. This is the combination that most directly expresses the point's classification.
• With San Yin Jiao SP-06 — its opposite number on the inner leg. The pair is used to balance yin and yang at the same level, and the relationship between the two has been examined directly in the “opposite acupoints” literature (Zhongguo Zhen Jiu 2017;37(10), PMID 29354976).
• Along its own channel — GB-39 sits between Yang Fu GB-38 above and Qiu Xu GB-40 at the ankle below, and the three form the channel's lower-leg group; Zu Lin Qi GB-41 on the foot is the usual distal partner for one-sided headache.

Where does GB-39 sit among its category peers?

The eight Hui-Meeting or influential points, set out in the Nan Jing, each govern one tissue or category across the whole body rather than one channel. All eight are held in Sacred Lotus sources & references, and the set is worth learning together because it lets a practitioner choose a point by the tissue involved rather than by where the complaint is felt:

• Zang organs — Zhang Men LIV-13
• Fu organs — Zhong Wan REN-12
• Qi — Shan Zhong REN-17
• Blood — Ge Shu BL-17
• Sinews — Yang Ling Quan GB-34
• Vessels — Tai Yuan LU-09
• Bones — Da Zhu BL-11
• Marrow — Xuan Zhong GB-39. This page.

Two of the eight sit on the Gall Bladder channel within a few inches of each other, GB-34 for sinews and GB-39 for marrow, which is why the lateral lower leg carries so much weight in the treatment of the musculoskeletal system. The pairing of bone (Da Zhu BL-11) and marrow (Xuan Zhong GB-39) is the other one to hold in mind, since the two categories are treated as related but distinct: bone is the structure, marrow the substance within it.

Source: Sacred Lotus sources & references (location, channel and Hui-Meeting records — the full set of eight queried from our own holdings); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 456); Chinese Acupuncture & Moxibustion (p. 220); Nan Jing, Difficulty 45; PMID 33559430; PMID 17313004; PMID 29354976; cross-referenced against multiple online sources.

Where is GB-39 located?

• A Manual of Acupuncture (p. 456): Above the ankle joint, 3 cun superior to the prominence of the lateral malleolus, between the posterior border of the fibula and the tendons of peroneus longus and brevis.
• Chinese Acupuncture and Moxibustion (p. 220): 3 cun above the tip of the external malleolus, on the anterior border of fibula.

How is GB-39 Xuan Zhong needled?

Reference fact: the standard texts record perpendicular insertion at Xuan Zhong, with Sacred Lotus sources & references giving 0.3 to 0.5 inch and moxibustion applicable, and Deadman & Al-Khafaji recording a somewhat deeper range of roughly 0.5 to 1 cun perpendicular or obliquely directed upward along the channel. These figures are recorded here as neutral reference data describing what the textbooks state. They are not instruction, and this page does not teach technique. Needling is carried out only by a qualified, licensed practitioner.

What lies beneath the point

• This is a comparatively low-hazard point, and it is worth saying so directly rather than attaching a generic warning. GB-39 lies over the lower leg on or beside the fibula, with bone immediately deep to it. There is no lung, no great vessel and no viscus in reach, and the standard references attach no special prohibition to it. It carries none of the anatomical exposure of points such as Feng Fu DU-16 at the skull base, Jian Jing GB-21 over the lung apex or the points over the thorax.
• The structures that are present are the peroneal (fibular) muscles and their tendons and the superficial peroneal nerve, which becomes superficial in the lower third of the leg in this region. Contact with a cutaneous nerve produces a sharp, electric sensation rather than injury, and the reference literature treats this as a normal caution of technique rather than as a hazard.
• Location affects what the needle meets. Because the anterior and posterior descriptions of this point place the needle on opposite sides of the fibula — the disagreement flagged under practice above — the tissue encountered differs between the two descriptions. That is one practical consequence of a location dispute that might otherwise look academic.
• Moxibustion is recorded as applicable, and GB-39 features in the classical practice of moxa at Zu San Li ST-36 and Xuan Zhong GB-39 as a preventive measure, a use that has been examined in the modern Chinese literature (Zhongguo Zhen Jiu 2006;26(3), PMID 16570432).

The general safety picture

For context rather than alarm: a meta-analysis of prospective clinical studies estimated serious adverse events from acupuncture at approximately 1 per 10,000 patients and around 8 per million treatments, with about half of all recorded events being bleeding, pain or flare at the needle site, and concluded that acupuncture is among the safer treatments in medicine (Bäumler P et al., BMJ Open 2021;11:e045961, PMID 34489268). The serious events recorded in the literature cluster at a small number of anatomically exposed points, and GB-39 is not among them.

Source: Sacred Lotus sources & references (existing needling record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 456); Chinese Acupuncture & Moxibustion (p. 220); PMID 16570432; PMID 34489268 — each record checked as active and not retracted.

What does the name Xuan Zhong mean?

Xuan Zhong means “Suspended Bell” — xuan, to hang or suspend, and zhong, a bell. The usual explanation given in the sources is charmingly literal: this is the height on the lower leg at which children in old China wore small bells tied above the ankle, so the point was named for where the bell hung. Our translation record also carries “Suspended Time”, reflecting the other sense of zhong as a clock or timepiece — a later reading of the same character.

The point's other name matters more. It is at least as widely known as Jue Gu (絕骨), “Severed Bone” or “Terminated Bone”, from the palpable notch or step felt where the fibula's shaft can be traced along the outer leg. That name is the clue to the classification: a point named for bone became the point that governs marrow, the substance the classics say fills bone. Readers will encounter both names, and some texts treat Jue Gu and Xuan Zhong as very slightly different locations — which is part of the background to the location disagreement flagged in the practice section above.

Why does the Hui-Meeting point of Marrow classification matter?

The eight Hui-Meeting points, set out in the Nan Jing, each influence one tissue or category throughout the whole body rather than one channel or organ. GB-39 is assigned marrow (sui), and the Chinese category is wider than the English word. It covers the substance within the bones, and also the spinal cord and the brain, which the classics call the Sea of Marrow. That breadth is why a point on the ankle carries indications reaching to the head. The chain of reasoning runs: the Kidneys store essence, essence produces marrow, marrow fills the bones and the brain — so a point that governs marrow can be reached for in disorders of bone, of the spine, and of the head. The practical consequence is that GB-39 is selected as a distal point on the basis of tissue, not location: for a bone disorder anywhere, not merely for the leg it sits on. That single fact is the most useful thing to carry away about this point.

Is there research on GB-39 Xuan Zhong?

GB-39 has a real point-specific research literature, and it is unusual in one respect worth stating up front: the point has been used repeatedly as a comparison point in studies designed to test whether acupuncture points have specific effects — and in that role it has produced honest negative results.

• Point-specificity in period pain — a negative finding, reported as such. Fifty-two women with primary dysmenorrhoea were randomised to electroacupuncture at San Yin Jiao SP-06, at Xuanzhong GB-39, at an adjacent non-channel point, or to a waiting list, with menstrual pain and uterine artery blood-flow indices as outcomes. SP-06 reduced pain substantially more than the waiting list, more than GB-39, and more than the non-channel point; GB-39 did not differ meaningfully from the non-channel control, and no group differed on the blood-flow measures (Ma YX et al., Pain Med 2010;11(10):1564–75, PMID 21199306, DOI 10.1111/j.1526-4637.2010.00949.x). A companion study reported the same comparison for uterine arterial blood flow (J Altern Complement Med 2010;16(10), PMID 20932189). The finding is worth stating plainly in both directions: it supports the idea that points differ from one another, and it is evidence that GB-39 is not a point for menstrual pain — which is exactly what the traditional indications say.
• Stroke — the largest clinical study. A three-centre single-blind randomised controlled trial in 160 patients with ischaemic stroke added acupuncture at Zu San Li ST-36 and Xuanzhong GB-39 to routine treatment, and reported significant improvement in transcranial Doppler indices of cerebral vasomotor reactivity, blood-flow autoregulation and collateral circulation against control (Zhongguo Zhen Jiu 2006;26(12):851–3, PMID 17313004). A two-point add-on protocol with a physiological outcome measure rather than a clinical one, so it should not be read as evidence that acupuncture improves stroke recovery.
• Brain imaging. Functional MRI studies have examined electroacupuncture at Tong Li HT-05 and Xuanzhong GB-39 for effects on language-related brain areas in healthy volunteers, reporting distinguishable activation patterns (Chin J Integr Med 2016;22(11), PMID 26129898; J Int Med Res 2017;45(6), PMID 28868952). These are small mechanism studies in healthy people, not clinical evidence.
• Bone and marrow — the classification tested. Preclinical work has begun to examine the point's traditional territory directly. Electroacupuncture at Foot Shao Yang points including Xuanzhong GB-39 was studied in ovariectomised rats as a model of postmenopausal osteoporosis, with micro-CT measures of bone mineral density and trabecular structure and markers of bone formation, reported through the PI3K/AKT pathway (Zhen Ci Yan Jiu 2026;51(1):96–105, PMID 41566737). Rat work using a three-point protocol; it is suggestive of interest in the marrow-and-bone claim rather than a test of it.
• Inflammation and joints. Electroacupuncture at Zu San Li ST-36 and Xuanzhong GB-39 has been studied in adjuvant-arthritis rats for effects on synovial angiogenesis (J Tradit Chin Med 2023;43(5), PMID 37679983) and on serum matrix metalloproteinases (Zhen Ci Yan Jiu 2019;44(9), PMID 31532135).
• Small clinical reports. Older Chinese-language reports describe acupuncture at Xuanzhong in 106 cases of non-suppurative costal chondritis (J Tradit Chin Med 1998;18(3), PMID 10453612), in orthopaedic postoperative pain with Ashi points (Zhongguo Zhen Jiu 2007;27(12), PMID 18271231), and in calcaneal spur combined with a herbal dressing (Zhongguo Zhen Jiu 2010;30(3), PMID 20496730). These are small, unblinded and single-centre, and are listed for completeness rather than offered as evidence.

The honest summary: no adequately powered trial isolates GB-39 for its principal traditional indications — the neck, and disorders of bone and marrow — and the best-designed study that used it found it no better than a non-channel point for a condition it was never claimed to treat. What the point has is a coherent classical rationale, a consistent documented use, and a growing preclinical literature aimed at the bone-and-marrow claim.

How does Xuan Zhong compare with the points around it?

Yang Ling Quan GB-34 lies higher on the same channel below the knee and is the Hui-Meeting point of the Sinews — the two are the channel's pair of influential points, and the sinew/marrow division between them is the cleanest illustration of what the Hui-Meeting scheme is for. Da Zhu BL-11 beside the first thoracic vertebra is the Hui-Meeting point of the Bones and is GB-39's natural partner where structure and substance are both at issue. San Yin Jiao SP-06 is its exact mirror on the inner leg, three cun above the medial malleolus, and is the far better known of the two — the point-specificity trials cited above set them against each other directly. Yang Fu GB-38 sits just above GB-39 on the same channel and Qiu Xu GB-40, the yuan-source point, just below at the ankle; both are more local in their range. Where GB-39 stands apart from all of these is in being chosen for a tissue rather than a place.

Source: Sacred Lotus sources & references; Deadman & Al-Khafaji, A Manual of Acupuncture (p. 456); Chinese Acupuncture & Moxibustion (p. 220); Nan Jing, Difficulty 45; PMID 33559430; PMID 21199306; PMID 20932189; PMID 17313004; PMID 26129898; PMID 28868952; PMID 41566737; PMID 37679983; PMID 31532135; PMID 10453612; PMID 18271231; PMID 20496730 — each record checked as active and not retracted; cross-referenced against multiple online sources.