Gabapentin Plus Hegu Embedding Improved Post-Herpetic Neuralgia

TL;DR: A 2026 single-center randomized trial in Pakistan Journal of Pharmaceutical Sciences found adding weekly Hegu-point catgut embedding to gabapentin improved post-herpetic neuralgia pain, sleep, response rate, and adverse-event rates versus gabapentin alone.

Source: Pakistan Journal of Pharmaceutical Sciences (2026) | Li et al.

Post-herpetic neuralgia can persist long after the shingles rash resolves. This trial tested whether gabapentin works better when paired with Hegu-point catgut embedding, a sustained LI4 stimulation technique intended to keep acting between clinic visits.

Gabapentin Alone Left Post-Herpetic Neuralgia Pain and Sleep Burden

PHN can linger for months after varicella-zoster reactivation, with burning, stabbing, electric-shock pain and severe allodynia. Sleep disruption is a second major burden.

People stop sleeping well, become more pain-sensitive, more anxious, and harder to stabilize. Gabapentin is standard care because it dampens excitatory transmitter release through alpha2delta calcium-channel modulation, but response is often partial and side effects can limit dosing.

The add-on tested here was Hegu-point catgut embedding — prolonged LI4 acupoint stimulation using absorbable thread that keeps mechanically stimulating the site for a week or two.

The framing is that this maintains pressure on pain transmission, inflammatory signaling, and endogenous opioid release more steadily than a single acupuncture session can.

Pain Response and Sleep Improvement Drove the Hegu Embedding Result

210 PHN patients, ages 40–70, definite diagnosis with pain ≥3 months, baseline VAS ≥4. Randomized 1:1: gabapentin alone vs. gabapentin plus weekly bilateral Hegu embedding for 4 weeks.

Both groups got the same routine care package — neurotrophic medication, skin care, sleep hygiene counseling, exercise/diet/emotional-support measures.

The comparison was gabapentin alone versus gabapentin plus a sustained Hegu embedding procedure. The trial tested whether the add-on improved pain and sleep outcomes beyond standard drug treatment, not whether gabapentin works by itself.

Pain on the VAS fell from 7.56 to 3.22 in the combination group vs. 7.47 to 4.18 in the gabapentin-only group. PSQI sleep scores dropped from 14.25 to 5.34 with the combination vs.

13.96 to 7.65 in controls — almost a 9-point sleep improvement vs. about 6.3. Response (defined as ≥50% VAS reduction): 92.38% vs 80.00%.

Post-Herpetic Neuralgia Pain and Sleep Scores Improved Together

The striking part is the paired outcome. The add-on moved two outcomes that usually travel together in PHN: pain intensity and the sleep damage pain causes.

PHN treatment should be judged partly by whether people can sleep again, alongside whether the pain score moves down. On both endpoints, the Hegu embedding plus gabapentin group outperformed gabapentin alone.

The biomarker panel is where researchers try to ground the symptom change in something more mechanistic. The direction was consistent across both groups but steeper with the combination:

• Substance P: fell from 82.54 to 46.69 pg/mL in the combination vs. 81.73 to 52.23 pg/mL in controls.
• IL-6: 19.15 to 7.35 pg/mL with combination vs. 18.92 to 12.58 pg/mL alone.
• TNF-α: ended at 5.83 pg/mL with combination vs. 7.02 alone.
• β-endorphin: increased from 32.17 to 68.34 ng/L combined vs. 33.56 to 57.26 ng/L alone.

Researchers interpret the pattern as a combined effect on pain transmission, inflammation, and endogenous analgesia. None of that proves a precise pathway from thread placement to spinal or cortical pain relief, but the symptom improvement and serum changes make a placebo-only explanation less likely.

Lower Adverse-Event Rates Strengthened the Hegu Add-On Result

The most practically useful number was tolerability. Adverse events were 12.38% in the combination arm vs.

26.67% in controls. Dizziness and somnolence were both lower in the combined arm — despite adding a procedure on top of the drug, with the additional possibility of local-site pain or swelling.

That changes the usual objection to add-on therapies. The combined regimen performed better on efficacy and looked easier to tolerate in the short term, rather than trading pain relief for more side effects.

Researchers suggest better symptom control may have allowed lower effective gabapentin exposure, though they do not present a formal dose-comparison table. The safer reading is narrower: fewer common gabapentin-type side effects in the combined arm, but the trial did not fully prove why.

Single-Center Hegu Trial Still Needs Sham-Controlled Replication

Restraint matters here. The study was randomized and assessor-blinded but not patient-blinded, and it did not include a sham-embedding control.

That leaves a wide opening for expectancy effects, especially when both major endpoints — pain and sleep — are subjective and highly vulnerable to context.

Follow-up was 4 weeks. PHN can last months or years, so the trial showed short-term improvement, not durable remission.

No quality-of-life, functional-recovery, or longer-term relapse endpoints were included. And because everything came from one center using one acupoint protocol, replication across clinicians, hospitals, and patient populations is unproven.

The trial sits at the edge of neuroscience rather than in its center.

PHN begins as peripheral nerve injury, but the outcomes included sleep disruption, neuroactive pain signaling, inflammation, and a brain-active drug.

That combination makes the result more concrete than many complementary-medicine reports — even though the no-sham design leaves the subjective endpoints exposed to expectancy effects. The next study should add sham embedding, longer follow-up, and multi-center recruitment before any practice guideline is willing to act on it.