REN-24 (Cheng Jiang) Sauce Recepticle, Container of Fluids

What does REN-24 Cheng Jiang do?

Cheng Jiang REN-24 is the twenty-fourth and final point of the Conception Vessel, sitting in the hollow of the chin below the lower lip, and it is a meeting point of four channels at once — the Conception Vessel with the Governing Vessel and with the Large Intestine and Stomach channels. Sacred Lotus sources & references record that classification, together with its listing among Sun Si-miao's Ghost points. Four channels converging on one small depression is the reason a point on the chin is used for complaints of the whole face, mouth and jaw.

• Extinguishes wind and benefits the face — the defining action, recorded first in our own action record. In classical theory, sudden one-sided distortion of the face is attributed to wind attacking the channels of the head, and REN-24 is one of the standard points for it: facial paralysis, deviation of the mouth and eyes, twitching and spasm of the face.
• Regulates the Conception Vessel — the terminal-point action. REN-24 is where the front midline vessel ends, and it is the point at which the Conception Vessel is described as meeting the Governing Vessel coming over the head and down the face, closing the loop the two vessels make around the trunk.
• Benefits the mouth, gums and teeth — the local action, and the one most used. Swelling and pain of the gums, toothache in the lower jaw, ulceration of the mouth, and pain or stiffness of the jaw all fall in its territory.
• Regulates the fluids of the mouth — the action the name points to. REN-24 is recorded for excessive salivation and drooling on the one hand and for a dry mouth on the other, and it appears in the classical prescriptions for both.
• Calms the spirit — the Ghost-point action. Sun Si-miao's group of thirteen Ghost points was assembled for disorders of the mind, and REN-24's recorded use for mental disturbance and for epilepsy comes from that classification rather than from its location.

Source: Sacred Lotus sources & references (channel, four-channel meeting-point and Sun Si-miao Ghost-point classifications, existing action record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 524); Chinese Acupuncture & Moxibustion (p. 241); Qian Jin Yao Fang (Sun Si-miao) for the Ghost points; cross-referenced against multiple online sources.

What is REN-24 Cheng Jiang used for?

Cheng Jiang REN-24 is used above all for the face, mouth and jaw — facial paralysis, gum and tooth complaints, and disorders of salivation. The indications below are those carried in Sacred Lotus sources & references together with those set out in the standard reference literature. They describe traditional use, not proven treatment.

• Facial paralysis and deviation of the eyes and mouth
• Facial swelling and puffiness
• Swelling and pain of the gums
• Toothache, particularly of the lower teeth
• Ulceration and sores of the mouth
• Excessive salivation and drooling
• Dry mouth
• Stiffness, pain and spasm of the jaw; difficulty opening the mouth
• Loss of voice and sudden hoarseness
• Facial twitching and spasm
• Mental disturbance
• Epilepsy
• Stiffness and pain of the neck, with difficulty turning the head

Source: Sacred Lotus sources & references (existing indication record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 524); Chinese Acupuncture & Moxibustion (p. 241).

Where is REN-24 Cheng Jiang, and how is it used in practice?

Cheng Jiang lies in the middle of the horizontal groove between the lower lip and the chin — the mentolabial groove — directly below the centre of the lip. Sacred Lotus sources & references give it as the depression in the centre of that groove, above the chin. It is one of the easiest points on the body to find: it is the natural dip a fingertip falls into when run down from the middle of the lower lip, and it needs no measurement.

In practice REN-24 is a local point of the lower face. It is chosen when the complaint is in the chin, the lower lip, the lower gums and teeth, or the jaw, and it is a standing member of the facial-paralysis prescription. Because it lies at the junction of four channels it also serves as a connecting point in facial treatments — the place where a treatment working up the front of the body and one working down the face meet.

Which points is REN-24 combined with?

• With DU-26 Shui Gou — the classical pair, and the one worth learning first. DU-26 sits in the vertical groove between the nose and the upper lip; REN-24 sits in the horizontal groove between the lower lip and the chin. One is directly above the mouth and one directly below it, and the two are used together for facial and orofacial complaints. The symmetry is more than positional: Sacred Lotus sources & references record both as Sun Si-miao Ghost points, and both as meeting points with the Large Intestine and Stomach channels — DU-26 as a Meeting Point of the Governing Vessel with those two channels, REN-24 as a Meeting Point of the Conception Vessel with the Governing Vessel and those same two channels. They are the terminal meeting of the two great midline vessels, one on each lip.
• With ST-04 Di Cang, ST-06 Jia Che and LI-20 Ying Xiang — the standard local group for facial paralysis, running across the cheek, the jaw angle and the side of the nose. This is the combination the modern literature converges on: a review of 33 randomised controlled trials of acupuncture for peripheral facial paralysis, selected from 386 identified articles, reported that the best point options were Dicang ST-04, Xiaguan ST-07, Jiache ST-06, Chengjiang REN-24, Yingxiang LI-20, Quanliao SI-18, Yifeng SJ-17, Yangbai GB-14, Sibai ST-02, Fengchi GB-20, Shuigou DU-26, Yuyao and Hegu LI-04 (Am J Chin Med 2009;37(1):35–43, PMID 19222110). REN-24 and DU-26 both appear on that list, which is the modern echo of the classical pair.
• With LI-04 He Gu — the Command Point of the face and mouth, and the standard distal partner for any facial point. Local point on the chin with distal point on the hand is the basic structure of a facial treatment.
• With REN-23 Lian Quan — below on the throat above the Adam's apple, where the complaint involves the tongue, swallowing or salivation as well as the mouth.
• With ST-06 Jia Che and SJ-17 Yi Feng — for jaw pain, stiffness and difficulty opening the mouth.
• For dry mouth — a review of the acupuncture literature for radiation-induced dry mouth searched five classical Chinese acupuncture works for the points used for dry-mouth symptoms and found the most commonly recorded head-and-neck points to be Chengjiang REN-24, Shuigou DU-26, Duiduan DU-27, and the Jin Jin Yu Ye extra points beneath the tongue (held here as a single record) (Chin J Integr Med 2016;22(7):549–54, PMID 26311288). REN-24 heads that ancient list — again alongside DU-26.

Where does REN-24 sit among its category peers?

REN-24 belongs to two groups held in full in Sacred Lotus sources & references. As the terminal point of the Conception Vessel it is the last of the twenty-four points on the front midline, the vessel that begins at Hui Yin REN-01 in the perineum and runs the length of the front of the body; the Governing Vessel completes the circuit down the back and over the head, ending at DU-28 Yin Jiao inside the upper lip. As one of Sun Si-miao's Ghost points, REN-24 belongs to a group assembled for disorders of the mind; the twelve carrying that classification here are LU-11 Shao Shang, LI-11 Qu Chi, ST-06 Jia Che, SP-01 Yin Bai, BL-62 Shen Mai, P-07 Da Ling, P-08 Lao Gong, DU-16 Feng Fu, DU-23 Shang Xing, DU-26 Shui Gou, REN-01 Hui Yin and REN-24 Cheng Jiang. The set is classically given as thirteen and the lists vary between sources, particularly over the final point beneath the tongue; the twelve above are those our records carry the classification on.

Source: Sacred Lotus sources & references (REN-24 record; the Ghost-point set, DU-26's classifications and the facial points named above all queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 524); Chinese Acupuncture & Moxibustion (p. 241); Qian Jin Yao Fang (Sun Si-miao); PMID 19222110; PMID 26311288; cross-referenced against multiple online sources.

Where is REN-24 located?

• A Manual of Acupuncture (p. 524): Above the chin, in the depression in the centre of the mentolabial groove.
• Chinese Acupuncture and Moxibustion (p. 241): In the depression in the centre of the mentolabial groove.

How is REN-24 Cheng Jiang needled?

Stated plainly: the reference texts record a very shallow, obliquely upward insertion at REN-24 — Sacred Lotus sources & references give 0.2 to 0.3 inch, angled upward, with moxibustion applicable. That is among the smallest depths recorded for any point on the body, and it is a consequence of the anatomy rather than of a hazard: the point lies in a shallow groove where skin and muscle sit directly on the jawbone, and there is very little tissue to enter. Everything below is recorded as neutral reference data describing what the textbooks state. It is not instruction, and this page does not teach technique. Needling is carried out only by a qualified, licensed practitioner.

The angle and depth the texts record

• Sacred Lotus sources & references record oblique insertion directed upward of 0.2 to 0.3 inch, with moxibustion applicable. Upward means toward the lip, along the face; the alternative recorded in the literature is a transverse insertion angled sideways along the groove when the intention is to affect the lower lip and gums.
• Deadman & Al-Khafaji (p. 524) and Chinese Acupuncture & Moxibustion (p. 241) record a comparable shallow oblique or transverse insertion. All three records agree; there is no meaningful divergence at this point.
• Moxibustion is recorded as applicable, though direct moxibustion is generally avoided on the face for cosmetic reasons — scarring on the chin is a permanent and visible outcome, and the reference literature notes the general caution about scarring techniques on facial points.

Where REN-24 sits on the risk scale — the honest answer

• It is a low-hazard point, and it should be described as one. REN-24 is not over the thorax, not over an abdominal organ, not near the eye, and not over a major vessel. It carries none of the organ-injury cautions attached to REN-15 below the breastbone or REN-17 on the breastbone itself, and it is not among the points the classical texts restrict in pregnancy. The recorded depth is small because the tissue is thin, not because something dangerous lies beneath it.
• What is genuinely nearby. The mental nerve — the sensory nerve of the lower lip and chin — emerges from the jawbone on each side below the corner of the mouth, and the labial branches of the facial artery and vein run in the same region. Both lie to either side rather than in the midline groove where REN-24 sits. The commonest minor events at any facial point are bruising and a brief sharp sensation; because the face bruises visibly and heals slowly, practitioners generally use fine needles and shallow angles here as a matter of course.
• No point-specific measured-depth study exists. We searched for an imaging or cadaveric study measuring safe depth at REN-24 itself and did not find one. Rather than borrow a figure measured elsewhere, the honest statement is that the textbook range above is what the literature holds for this point. Two systematic reviews of the safe-depth literature — 33 studies in the first, 47 in the second, by MRI, CT, ultrasound and dissection — both concluded that measured depths for the same point differ greatly between subject groups and methods, and that "safe depth" has never been standardised (J Altern Complement Med 2011;17(3):199–206, PMID 21417806; Evid Based Complement Alternat Med 2013;2013:740508, PMID 23935678).
• What has been recorded at REN-24 specifically. The one controlled trial of this point alone used a 0.2 × 13 mm disposable needle inserted to 10 mm at Chengjiang, in 41 patients, and reported no adverse effects attributable to it (PMID 14736356, described under research below). Ten millimetres sits inside the textbook range above, and it is the only depth figure published for the point in a clinical study we could locate.

The proportion of the risk

A meta-analysis of prospective clinical studies estimated serious adverse events in acupuncture at approximately 1 per 10,000 patients and around 8 per million treatments, placing it among the safer treatments in medicine (Bäumler P et al., BMJ Open 2021;11:e045961, PMID 34489268). That small residual risk is concentrated in the points over the chest, upper back and abdomen. REN-24 is not one of them.

Source: Sacred Lotus sources & references (existing needling record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 524); Chinese Acupuncture & Moxibustion (p. 241); PMID 14736356; PMID 21417806; PMID 23935678; PMID 34489268 — each verified resolvable and checked for retraction status before citation.

What does the name Cheng Jiang mean?

Cheng Jiang means "Sauce Receptacle" or "Container of Fluids" — cheng, to receive or to hold up from below, and jiang, a thick liquid, broth or sauce. Sacred Lotus sources & references translate it both ways. The name is a plain description of what the hollow beneath the lower lip does: it is the place where liquid collects and is caught when it escapes the mouth. That is also the clinical point of the name — REN-24 is the classical point for drooling and for excessive salivation, and it appears in the ancient prescriptions for dry mouth as well, on the reasoning that the same point governs the fluids of the mouth in either direction.

Why is REN-24 paired with DU-26 Shui Gou?

Because they are the two midline points of the mouth — one directly above it and one directly below — and they are the terminal meeting of the two great midline vessels. DU-26 Shui Gou, "Water Trough", lies in the vertical philtral groove between the nose and the upper lip. REN-24 lies in the horizontal groove between the lower lip and the chin. The Conception Vessel rises up the front of the body and ends at REN-24; the Governing Vessel runs up the back, over the head and down the face, ending inside the upper lip at DU-28 Yin Jiao, passing through DU-26 on the way. Sacred Lotus sources & references record REN-24 as a Meeting Point of the Conception Vessel with the Governing Vessel and the Large Intestine and Stomach channels, and DU-26 as a Meeting Point of the Governing Vessel with the Large Intestine and Stomach channels — the same three channels, on opposite lips. Both are also Sun Si-miao Ghost points. Their clinical ranges reflect the symmetry: both are used for facial paralysis and deviation of the mouth, both for orofacial complaints, and both are recorded in the classical dry-mouth prescriptions (PMID 26311288). The two are not interchangeable, however: DU-26 has a strong separate identity as the emergency point for collapse and loss of consciousness, and as a point for acute lower back sprain, neither of which belongs to REN-24. A reader looking for "the point above the lip" wants DU-26; "the point below the lip" is this one.

Is there research on REN-24 Cheng Jiang?

REN-24 has something very few acupuncture points have: a blinded, randomised, sham-controlled trial of a single needle at this point alone.

• The single-needle trial. Forty-one patients undergoing transoesophageal echocardiography — a procedure in which a probe is passed down the gullet, and which reliably provokes gagging — were allocated to receive one 0.2 × 13 mm needle inserted 10 mm at Chengjiang, or a superficial needle at a sham point on the tip of the chin, or no acupuncture. Gagging was rated by the patient on a visual analogue scale. The acupuncture group gagged significantly less than the sham group (P = 0.037) and than the no-acupuncture group (P = 0.013); the authors concluded that acupuncture of CV-24 is an easily applied and effective method of reducing the gag reflex during the procedure (Rösler A et al., J Altern Complement Med 2003;9(6):847–9, PMID 14736356). It is a pilot trial of 41 people conducted in a single German stroke unit, and it should not be read as more than that. But the design is the one that matters: one needle, at this point, against a sham needle a couple of centimetres away on the same chin, with a blinded patient-reported outcome. Very little of the acupuncture literature isolates a single point that cleanly.
• Facial paralysis, in the modern consensus. The review of 33 randomised controlled trials described above identified Chengjiang REN-24 among the recommended points for peripheral facial paralysis, alongside DU-26 and the local Stomach channel points (PMID 19222110). REN-24 is one item in a multi-point prescription there, so the review shows what is used rather than what each point contributes.
• Dry mouth, in the classical record. The literature review of acupuncture for radiation-induced dry mouth searched five classical Chinese acupuncture works and found Chengjiang REN-24 at the head of the recorded head-and-neck points for dry-mouth symptoms (PMID 26311288). This measures what was chosen historically, not whether it worked.
• Trigeminal neuralgia. A randomised trial of 65 patients with primary trigeminal neuralgia compared deep needling of Xiaguan ST-07 to reach the sphenopalatine ganglion against conventional superficial needling, with Chengjiang REN-24, Cuanzhu BL-02 and Sibai ST-02 among the auxiliary local points used in both arms and LI-04 and LIV-03 distally (Chin J Integr Med 2012;18(3):214–18, PMID 22466947). The variable under test was the depth at ST-07, not REN-24, and the trial is recorded here only as documented clinical use of the point.

What is missing should be said plainly: apart from the gag-reflex pilot trial, there is no controlled study isolating REN-24 for facial paralysis, for gum and tooth complaints or for disorders of salivation — its principal traditional uses. The gag-reflex finding is genuinely point-specific and genuinely sham-controlled, and it is also a single small pilot in a setting far removed from the point's usual clinical use.

How does REN-24 compare with the points around it?

Shui Gou DU-26 above the lip is REN-24's counterpart and its most important comparison, set out above. Jia Cheng Jiang, "Adjacent to Cheng Jiang", is the extra point held here at the same level but one cun to either side, over the point where the mental nerve emerges from the jaw; it is the more local choice for one-sided chin and lower-lip complaints, where REN-24 on the midline is the choice for the mouth as a whole. Di Cang ST-04 at the corner of the mouth and Jia Che ST-06 at the angle of the jaw are the two Stomach channel points REN-24 is most often needled with in facial treatment; ST-06 is also a Ghost point. Lian Quan REN-23 is the next point down the Conception Vessel, above the Adam's apple, and takes over where the tongue and swallowing are involved. Duiduan DU-27 and Yin Jiao DU-28 complete the Governing Vessel at the upper lip and inside it, the mirror of REN-24's position below. And He Gu LI-04 on the hand is the distal Command Point of the face and mouth, the point that reaches all of REN-24's territory from the other end of the body.

Source: Deadman & Al-Khafaji, A Manual of Acupuncture (p. 524); Chinese Acupuncture & Moxibustion (p. 241); Sacred Lotus sources & references (REN-24 record; DU-26 and the Ghost-point set, the Jia Cheng Jiang extra point and the neighbouring facial points queried directly); Qian Jin Yao Fang (Sun Si-miao) for the Ghost points; PMID 14736356; PMID 19222110; PMID 26311288; PMID 22466947 — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.