LI4 Acupuncture Point (Hegu): Location, Functions & Uses

Curious why LI-4 feels the way it does during treatment? See LI-4 and De Qi Sensation for a deep dive into the nerves and De Qi sensation behind it.

Face pain, headaches, toothaches, the common cold, and — according to TCM theory — labour induction, LI4 shows up everywhere. There’s an old classical saying every student hears sooner or later: “For face and mouth issues, look to Hegu.” It’s one of the first clinical rules you learn, and it still holds up decades later and now science is telling us why.

Before getting into why it works, let’s make sure you know exactly where to find it.

Anatomy: How to Actually Find This Point

LI4 sits in the fleshy web between the thumb and index finger, but precision counts with this point. Many students make basic mistakes with its location, and it’s often due to the common “short-cut” everyone tends to learn.

The “Short-Cut” method: actively or passively, get the patient to bring their thumb and forefinger together. LI4 sits at the highest point of the muscle bulge (the first dorsal interosseous) when the thumb is adducted toward the index finger — right around the midpoint of the 2nd metacarpal bone, just off its radial border. *I see students use this all the time — however, too many mistakes can be made with this method, and while it is fine for those looking to do acupressure in this area, it is not precise enough for those who are needling.

The measurement method (more precise): locate the proximal and distal ends of the 2nd metacarpal. Find the midway point of this bone and then palpate radially until you just fall off the bone — this is where you’ll find LI4. The point is between the thumb and index finger, but if found correctly, it will end up closer to the second metacarpal bone instead of the thumb. See my YouTube link below for the video demonstration.

Palpation tip: press firmly into the muscle belly between the metacarpals — most patients will report a distinct, often strong, achy sensation here even with just palpation pressure. That reactivity is a good confirmation you’re in the right spot. Needling will create a similar feeling.

Nearby Structures

• First dorsal interosseous muscle — the muscle belly LI4 sits within. Reaching this muscle layer with the needle is what recruits the deep, spreading ache (deqi) — a depth and tissue-type effect common to muscle stimulation generally, not specific to any one nerve.*
• Superficial branch of the radial nerve — provides sensation only to the overlying skin; responsible for the initial surface prick on insertion, not the deeper ache.
• Dorsal venous network of the hand — often visible; be mindful of visible veins.
• Radial artery (with an accompanying vascular branch of the SBRN) — passes through this region en route to the palm; anatomically the basis for LI4’s use in circulatory conditions like Raynaud’s, separate from its role in pain/deqi.

*This muscle’s motor supply is the deep branch of the ulnar nerve — not the radial nerve, despite sitting in radial-nerve skin territory. Worth knowing for anatomical precision, though the needle isn’t stimulating this nerve directly, and it isn’t established as the cause of the deep ache itself.  For an in-depth look at the anatomy of LI-4 and more and the sensation of De Qi at this point – see De Qi at LI-4.

The Western Science of LI4

The radial nerve’s role in circulation: LI4 sits remarkably close to a point where a vascular branch of the superficial radial nerve meets the radial artery (Umemoto et al., 2019) — anatomical basis for LI4’s classical use in peripheral circulatory conditions like Raynaud’s disease, distinct from its role in pain. One caveat: the study located LI4 using the traditional Japanese/Korean textbook convention rather than the WHO Standard location used elsewhere in this article, a discrepancy the authors clarified in a 2021 follow-up (Umemoto et al., 2021) — so treat the general finding as solid, but the exact 4.3mm distance as measured from a slightly different reference point.

What actually produces the deep ache: The strong deqi sensation at LI4 comes from reaching the muscle belly beneath the skin — a depth and tissue-type effect, not something specific to the radial nerve. Stimulating muscle tissue recruits slower-conducting Aδ and C nerve fibers responsible for aching, heaviness, and dull pain, while lighter, more superficial stimulation tends to produce numbness instead (Yang et al., 2013).

Analgesia and the opioid pathway: A randomized trial found that electroacupuncture at LI4 held plasma β-endorphin levels steady over 30 minutes, while a sham-treatment control group saw levels drop significantly — evidence consistent with a real opioid-mediated analgesic pathway at this point, even though LI4’s own levels didn’t rise dramatically in absolute terms (Setiawardhani et al., 2017).

Neuroimaging findings: Functional imaging studies show LI4 produces a distinctive brain response compared to many other commonly studied points. fMRI work has found differential brain activation between manual and electroacupuncture stimulation at LI4 specifically (Kong et al., 2002), and deqi at LI4 has been associated with deactivation of limbic-paralimbic brain regions alongside increased blood flow to the hypothalamus and insula — a pattern distinct from sharp pain, which activates rather than deactivates these same areas (Yang et al., 2013). This offers a plausible neurological basis for LI4’s broad effects on both physical pain and emotional/stress states, consistent with its classical role in the Four Gates combination.

Labor research: LI4 is part of a standardized multi-point protocol (with SP6 etc.) shown in a 2024 RCT to significantly increase spontaneous labor onset before scheduled induction (Zamora-Brito et al., 2024) — a notable finding, since prior evidence suggested acupuncture doesn’t reliably induce labor on its own. As a multi-point protocol, LI4’s individual contribution can’t be isolated. Separately, an earlier trial using LI4 acupressure alone found it significantly reduced pain during active labor, though it had no measurable effect on labor’s duration (Dabiri & Shahi, 2014) — useful evidence for LI4’s role in labor comfort specifically, distinct from the induction question. The pregnancy contraindication stands regardless of which direction the evidence points on either question.

The TCM Perspective

LI4 is the Yuan-Source point of the Large Intestine channel — Hand Yangming, paired with the Lung, belonging to the Metal element. As a Yuan-Source point, it has direct access to the Original Qi of the channel, which is part of why it’s so versatile: it can tonify, move, and regulate depending on technique and the point it’s combined with.

LI4 is also one of the Four Command Points — the classical group of points said to govern broad regions of the body (LI4 for the face and mouth, ST36 for the abdomen, BL40 for the back, LU7 for the head and nape). As the command point of the head and face specifically, LI4’s role in treating headache, jaw pain, toothache, and facial conditions isn’t just a long list of individual indications — it reflects this point’s classical status as the primary point for that entire region, reinforcing why “face and mouth, look to Hegu” became such a durable teaching rule rather than just one clinical pearl among many.

• Large Intestine channel: releases the Exterior, expels Wind, clears Heat, regulates the face, head, and mouth
• Metal element: governs the skin and body’s defensive layer (Wei Qi) — consistent with LI4’s role in fighting off external pathogenic invasion (colds, flu)
• Downward-moving action: LI4 has a strong descending quality, which is why it’s used to induce labor and why it’s contraindicated in pregnancy

Classical Indications:

• Headache, especially frontal and temporal
• Toothache, facial pain, facial paralysis
• Sore throat, common cold, flu with fever and chills
• Nasal congestion, sinus conditions
• Eye disorders (redness, pain)
• Excessive or deficient sweating
• Constipation, abdominal pain
• Dysmenorrhea (especially combined with SP6)
• Labor induction at term

Clinical Pearls from 25 Years in Practice

1. “Face and Mouth, Look to Hegu”

This is one of the first clinical mnemonics every student learns, and it still holds up. For almost any face, head, mouth, or dental complaint, LI4 is a reasonable first point to consider — it’s rarely the wrong call as part of a broader point prescription.

2. The Four Gates (LI4 + LV3)

LI4 combined with LV3 (Taichong) forms the Four Gates — one of the highest-yield combinations in the entire system. It opens the smooth flow of Qi and Blood throughout the body, and is a go-to for pain conditions (acute or chronic), stress and anxiety, and as an adjunct for blood pressure regulation. If you only remember one combination from this whole article, make it this one.

3. LI4 Is Strongly Contraindicated in Pregnancy

Like SP6, LI4’s strong downward-moving action makes it one of the classically forbidden points in pregnancy. According to TCM theory, LI4 combined with SP6 is an especially potent labor-inducing pairing — always confirm pregnancy status before needling this point, and treat this contraindication with the same seriousness you’d apply to SP6.

4. Manage the Deqi Sensation

LI4 is notoriously sensitive — many patients describe a strong, sometimes sharp, sensation here. For needle-anxious patients, warn them ahead of time and consider a gentler initial stimulation. For patients who tolerate it well, that strong deqi is often part of why LI4 is so clinically effective for pain.

5. An Excellent Distal Point for Pain, Anywhere

Don’t limit LI4 to local hand or face complaints. Its strong analgesic action makes it a useful distal point in point prescriptions for pain conditions well outside its local territory — low back pain, general pain management protocols, and as part of broader analgesic combinations.

Interesting and Unexpected Applications

Dental and minor surgical analgesia: LI4 is one of the most-used points in acupuncture analgesia protocols, including as an adjunct to reduce anesthetic requirements during dental procedures.

Labor induction and augmentation: According to TCM theory, LI4 — often combined with SP6 — is used at term (38+ weeks) to help encourage labor onset, under appropriate clinical supervision.

Sweating disorders: LI4 paired with KD6 forms a classic “opening/closing” combination used to regulate both excessive sweating and an inability to sweat, depending on the pattern.

Stroke rehabilitation: LI4 frequently appears in upper-limb rehabilitation point protocols following stroke, often combined with other Large Intestine and Yangming channel points.

Stress and emotional regulation: Through the Four Gates combination, LI4 has a real role in TCM emotional-regulation protocols — don’t reserve it only for physical pain.

Contraindications and Cautions

• Pregnancy: LI4 is strongly contraindicated during pregnancy, in the same category as SP6. Its downward-moving action can stimulate uterine contractions. This applies to needling and acupressure alike. The only exception is intentional use at term, under appropriate clinical supervision, based on TCM teaching that this supports labor onset.
• Bleeding risk: The dorsal hand has visible superficial veins in many patients — take care in patients on anticoagulants or with bleeding disorders.
• Technique: Needle toward the center of the hand, avoiding excessive depth toward the metacarpal periosteum. In highly sensitive or needle-anxious patients, a gentler initial stimulation reduces discomfort without sacrificing effect.

References

Umemoto, K., Naito, M., Tano, K., Terayama, H., Koike, T., Ohmichi, M., Ohmichi, Y., Sakabe, K., & Nakano, T. (2019). Acupuncture Point “Hegu” (LI4) Is Close to the Vascular Branch from the Superficial Branch of the Radial Nerve. Evidence-Based Complementary and Alternative Medicine, 2019, 6879076. https://doi.org/10.1155/2019/6879076

Yang, X.-Y., Shi, G.-X., Li, Q.-Q., Zhang, Z.-H., Xu, Q., & Liu, C.-Z. (2013). Characterization of Deqi Sensation and Acupuncture Effect. Evidence-Based Complementary and Alternative Medicine, 2013, 319734. https://doi.org/10.1155/2013/319734

Setiawardhani, A. L., Srilestari, A., & Simadibrata, C. (2017). Electroacupuncture effect at the LI4 Hegu point on the plasma β-endorphin level of healthy subjects. Journal of Physics: Conference Series, 884, 012027. https://doi.org/10.1088/1742-6596/884/1/012027

Kong, J., Ma, L., Gollub, R. L., Wei, J., Yang, X., Li, D., Weng, X., Jia, F., Wang, C., Li, F., Li, R., & Zhuang, D. (2002). A pilot study of functional magnetic resonance imaging of the brain during manual and electroacupuncture stimulation of acupuncture point (LI-4 Hegu) in normal subjects reveals differential brain activation between methods. Journal of Alternative and Complementary Medicine, 8(4), 411–419. https://doi.org/10.1089/107555302760253603

Dabiri, F., & Shahi, A. (2014). The Effect of LI4 Acupressure on Labor Pain Intensity and Duration of Labor: A Randomized Controlled Trial. Oman Medical Journal, 29(6), 425–429. https://doi.org/10.5001/omj.2014.113

Zamora-Brito, M., Migliorelli, F., Pérez-Guervós, R., Solans-Oliva, R., Arranz-Betegón, A., & Palacio, M. (2024). Acupuncture before planned admission for induction of labor (ACUPUNT study): a randomized controlled trial. American Journal of Obstetrics & Gynecology MFM. https://doi.org/10.1016/j.ajogmf.2024.101477