Types and Doses of Pharmacopuncture for Lumbar Disc Herniation: a scoping review of clinical studies

Abstract

Objectives

Lumbar disc herniation (LDH) symptoms include lower back pain (LBP), radiating leg pain, and muscle weakness in muscles innervated by the affected nerve roots. The treatment of LDH is divided into conservative and surgical treatments. In this study, we aimed to summarize and analyze the clinical studies of pharmacopuncture (PP) on LDH and to assess its utilization rate in clinical practice.

Methods

In this scoping review, we searched both the domestic (Research information sharing service [RISS], SCIENCE ON, online access to shared information system [OASIS]), and international (PubMed) databases to gather case reports, retrospective studies, and randomized controlled trials with information on the types and doses of PP by injection points up to September 3rd, 2024. The information obtained was analyzed using the PP type and dose at each injection point.

Results

Sixty-three studies were identified for this study. We observed that bee venom was most used (34 studies), followed by Shinbaro (29 studies). Studies on other PP types did not exceed four each. The PP doses ranged from a minimum of 0.04 cc to a maximum of 6.00 cc. The most used dose was 1.00 cc. Injection points were intradermal at each disc level, Ah-Shi points, tender points, muscles, traditional acupoints, and facet joints.

Conclusion

We analyzed variations in injection points and maximum doses of PP according to substance type and anatomical location. These results support the development of standardized protocols for acupoint injection therapy in patients with LDH.

INTRODUCTION

Lumbar disc herniation (LDH) is a well-defined structural cause of radiculopathy, frequently associated with lower back pain (LBP), the leading cause of disability worldwide [1]. LDH involves the displacement of nucleus pulposus material through a ruptured annulus fibrosus, leading to compression or inflammation of adjacent nerve roots [2, 3]. Clinically, patients commonly present with unilateral radiating leg pain, numbness, and weakness in a dermatomal or myotomal distribution, often accompanied by LBP [4].

Magnetic resonance imaging (MRI) is considered the reference standard for diagnosis, enabling the visualization of disc pathology and its relationship to neural structures [5]. Nearly 95% of LDH occur at the L4-L5 and L5-S1 levels [6]. Although the global point prevalence of symptomatic LDH is estimated to be around 1%-3% in the adult population, it contributes significantly to disability and work-related productivity loss, particularly among adults aged 30 to 50 years [6, 7].

Treatment strategies for LDH are typically divided into conservative and surgical approaches. While surgical discectomy provides faster symptom relief in selected patients, multiple studies report comparable long-term outcomes with conservative management [8, 9]. Therefore, non-surgical interventions remain the first-line option for many patients, especially in the absence of red flag signs such as cauda equina syndrome or progressive motor deficits [4].

Pharmacopuncture (PP) has gained increasing clinical traction as a conservative treatment modality for LDH [10]. This therapy integrates the mechanical stimulation of acupuncture with the pharmacological effects of injected substances, typically herbal extracts, by delivering them directly into acupuncture points [10]. Its application has been documented in the management of a range of musculoskeletal and neurologic conditions, including discogenic radiculopathy, due to its potential anti-inflammatory, analgesic, and neuroregulatory properties [11].

Despite its growing use, the current literature on PP reveals considerable heterogeneity in the substances used, doses, injection techniques, and targeted anatomical sites. Furthermore, previous studies have not sufficiently examined the dose of acupoint injection therapy in relation to factors such as the type of injected substances, the selected acupoints, and injection depth. This insufficient detail limits the standardization and evidence-based application of this therapy in routine clinical settings.

This scoping review aims to systematically map clinical studies that have investigated acupoint injection therapy for LDH, with a specific focus on the types of injectable substances, injection doses, anatomical sites, and administration practices. By identifying trends, inconsistencies, and research gaps, this review seeks to provide foundational evidence to inform the development of practical treatment guidance and support future research in integrative pain management for LDH.

METHODS

We conducted a scoping review according to the PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines [12] and used Arksey and O’Malley’s methodological approach to inform the review process [13]. The methodology was based on five steps: (1) identifying the research questions, (2) identifying relevant studies, (3) study selection, (4) data extraction, and (5) analyzing and reporting the results.

1. Identifying the research questions

The research questions were: (1) What types of PP are commonly used for LDH? (2) What injection doses are used in clinical studies of PP for LDH?

2. Identifying relevant studies

we searched four databases (PubMed, Research Information Sharing Service [RISS], Oriental Medicine Advanced Searching Integrated System [OASIS], and SCIENCE ON) from database inception to September 3, 2024. The following search string was used for PubMed: “Intervertebral Disc Displacement” (MeSH) or “Intervertebral Disc Degeneration” (MeSH) and pharmacoacupuncture or “acupoint injection” or “injection acupuncture” or “herbal acupuncture” or “hydro acupuncture” or aquacupuncture. Korean-language equivalents of terms related to “LDH” and “PP” were used for the Korean databases.

3. Study selection

1) Eligibility criteria

The principles of population, intervention, comparison, outcome, and study design (PICOS) formed the basis for the eligibility criteria.

(1) Population

Patients with LDH diagnosed using radiology (e.g., computed tomography (CT) or magnetic resonance imaging (MRI)) with no restrictions on sex, age, disease severity, or the presence of complications.

(2) Interventions

PP administered alone or in combination with other therapies (acupuncture, electroacupuncture, acupotomy, warming acupuncture, moxibustion, cupping, herbal medicine, herbal patch, Infrared radiation (IR), Transcutaneous Electrical Nerve Stimulation (TENS), Interferential Current Therapy (ICT), Silver Spike Point (SSP), ultra sound therapy, radiofrequency therapy, microwave therapy, deep heat meridian herbal steaming, chuna therapy, spinal traction therapy, manual therapy, thread embedding therapy, and Western medicine). PP refers to a therapeutic technique in which pharmacologically active substances, such as herbal extracts including bee venom or scolopendra, are injected directly into specific acupuncture points. In this study, we excluded conventional biomedical products such as lidocaine, steroids, and intravenous solutions to focus exclusively on interventions rooted in traditional East Asian medicine.

(3) Comparison

This study aimed to collect, organize, and analyze information about the types and injection doses of PP used in clinical practice; therefore, a comparison group was not required.

(4) Outcomes

No restrictions were placed on outcome variables.

(5) Study designs

Case reports, case-series retrospective studies, and RCTs were included in the analysis. Cross-sectional and prospective observational studies were excluded. There were no restrictions on publication date or status; however, only Korean and English publications were included to align with the study’s focus on Korean clinical practice.

2) Exclusion criteria

We excluded duplicate publications; studies that were not related to PP and LDH; and non-human studies, such as those conducted on animal models or in vitro. Systematic reviews and meta-analyses were also excluded, although their reference lists were screened to identify eligible primary studies. Studies that did not report injection doses were excluded, as dose was a key variable of interest. The absence of these data made it impossible to extract essential clinical parameters necessary for analysis. This exclusion criterion ensured methodological consistency and relevance to the review’s objectives.

3) Screening and consensus

We utilized Zotero for citation management and screening. Preliminary screening involved reviewing titles and abstracts, and the second screening involved examining the full text. Studies that met the eligibility criteria were included. Four researchers (M.L., Y.T., E.K., and G.P.) screened the articles independently. In cases of disagreement, the corresponding author (J.L.) adjudicated to reach a final decision.

4) Data extraction

Data extraction and management were conducted independently by two researchers (M.L and G.P). Extracted information included: (1) basic study information (title, authors, publication year, and study design) and (2) detailed information for the scoping review, including type and injection dose of PP, presence or absence of dose escalation, injection point (acupoint, muscle, tender point, and Ah-Shi point), patient information (sex, age, sample size, and LDH site), outcome measure (VAS, NRS, ODI, SLRT, ROM, MRI, RMDQ, SF-36, EQ-5D, SF-MPQ, FIM, MMT, and PRS) and therapeutic results. Information on injection points was extracted only for acupoints and anatomical regions located in the lumbar area. Microsoft Excel tables were used to organize the extracted information. The corresponding author (J.L.) reviewed and confirmed the extracted information.

5) Analyzing and reporting the results

The extracted information was collated into tables and systematically analyzed. The primary analysis examined the type and dose of PP at each injection site, and the findings were presented using tables and line graphs. These summarized data were used to support the quantitative presentation of results.

RESULTS

1. Study selection

We identified 445 studies from the selected databases. Fifty-seven duplicate studies were excluded before screening. The titles and abstracts of 388 studies were screened, of which 302 were excluded. Subsequently, a full-text review was conducted on 86 studies, and 7 studies in which the full text was unavailable were excluded. In addition, 16 studies were excluded based on the following criteria: no information on PP dose & acupoint (n = 11) and Chinese language (n = 5). Consequently, 63 studies (case reports, retrospective studies, and RCTs) were included in the analysis (Fig. 1).

Figure 1.

Flow chart of study selection process.

2. Study characteristics

All included studies were conducted in Korea (Table 1) [14-76]. Sample sizes ranged from 1 to 524 participants.

Table 1.

Characteristics of included studies

Author (year)	Sample size	Type of PP	Dose of PP (cc/injection point)	Originating herbal dispensary	Injection point	Outcome measure
Kim et al. [14] (2014)	1	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	Quadratus Lumborum	NRS 10 → 4; ODI 78 → 26; SLRT 20/60 → 40/60; Improvement in Lumbar ROM
		BV (NR)	1.00
Cha et al. [15] (2006)	10	BV (4,000:1)	0.20	Jaseng Hospital of Korean Medicine	Tender point, EX-B2, GB30	VAS 10 → 1.30 ± 0.67; Improvement in Lumbar ROM
Ryu et al. [16] (2019)	1	Shinbaro	4.00	Jaseng Hospital of Korean Medicine	Facet joint	NRS 5 → 1; ODI 77.78 → 42.22; SLRT 30/15 → 75/75
		eBV	1.50		Intradermal at disc level
Ju et al. [17] (2020)	1	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2	NRS 7 → 2; ODI 56 → 20; SLRT 30/70 → 60/70
Seong et al. [18] (2019)	1	Shinbaro	0.10	Jaseng Hospital of Korean Medicine	Tender point, Erector spinae	NRS 7 → 3; ODI 75.56 → 17.78
Yoo et al. [19] (2016)	41	Shinbaro	4.00	Jaseng Hospital of Korean Medicine	Facet joint	Comparison of herniated disc volume by MRI 1,321.62 ± 467.53 mm3 → 648.72 ± 313.38 mm3 (46.6% reduction)
Ju et al. [20] (2015)	1	Shinbaro	6.00	Jaseng Hospital of Korean Medicine	Facet joint	NRS 9 → 3; ODI 46 → 17
	1					NRS 8 → 3; ODI 46 → 10
	1					NRS 9 → 1; ODI 48 → 17
Choi et al. [21] (2022)	1	SBV1	0.10	Korean Pharmacopuncture Institute	BL22, BL23, BL24, BL25, BL26	NRS 5 → 1; ODI 39 → 12; EQ-5D 0.206 → 0.663; Improvement in Lumbar ROM
		Soyeom	0.25
Yun and Park [22] (2000)	1	BV (3,000:1)	0.10	Korean Pharmacopuncture Institute	BL23, BL24, BL25, BL31, BL32, BL33, BL34, GV3, GV4, GB30	VAS 6 → 1; SLRT 55/85 → 80/85
Cho et al. [23] (2006)	1	BV (3,000:1)	0.8	Korean Pharmacopuncture Institute	Erector spinae	VAS 10 → 2; Improvement in Lumbar ROM
Jun et al. [24] (2004)	20	BV (6,000:1)	1.00	Korean Pharmacopuncture Institute	EX-B2	VAS 7.15 ± 2.0138 → 2.60 ± 1.9574; DITI 0.6180 ± 0.2827 → 0.2145 ± 0.1328; Improvement in Lumbar ROM
Lee et al. [25] (2001)	1	BV (NR)	1.50	Korean Pharmacopuncture Institute	Ah-Shi point	VAS 9 → 0; SLRT 80/30 → 90/90
Song et al. [26] (2009)	15	Soyeom	1.00	Korean Pharmacopuncture Institute	EX-B2	VAS 6.87 ± 0.74 → 4.33 ± 1.11; SLRT 47.80 ± 11.95 → 58.80 ± 12.46
Ok et al. [27] (2017)	1	eBV	1.50	Jaseng Hospital of Korean Medicine	Facet joint	NRS 7 → 3.5; SLRT 30/30 → 60/70; RMDQ 19 → 6
	1					NRS 8 → 5; SLRT 50/50 → 70/60; RMDQ 22 → 8
Koh et al. [28] (2003)	10	Scolopendrid	0.50	Korean Pharmacopuncture Institute	Ah-Shi point	Mean ΔODI 19; Mean ΔDITI 0.32; Improvement in Lumbar & SLR ROM
Lee et al. [29] (2007)	20	BV (20,000:1)	0.60	Korean Pharmacopuncture Institute	Ah-Shi point	VAS 80 ± 14.51 → 28.5 ± 10.89; SLRT 33.57 ± 7.48 → 75.0 ± 13.23
	20	Ouhyul	0.60			VAS 70.5 ± 17.0 → 36.0 ± 20.62; SLRT 32.5 ± 5 → 72.5 ± 15
Ko et al. [30] (2022)	1	BV (30,000:1)	0.30	Korean Pharmacopuncture Institute	Erector spinae	VAS 5.1 → 2.8; ODI 78 → 42; PI-LL 25.28 → 3.89; SF-MPQ 30 → 6
Nam et al. [31] (2012)	39	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	Supraspinous lig.	VNRS 6.82 ± 1.91 → 3.82 ± 2.12; ODI 44.67 ± 17.61 → 39.21 ± 15.96
		BV (10,000:1)	1.00		Intradermal at disc level
Jung et al. [32] (2021)	1	Shinbaro	0.10	Jaseng Hospital of Korean Medicine	EX-B2	NRS 6 → 4; ODI 64 → 54; FIM 85 → 96; MMT grade3 → grade4
		BV (10,000:1)	0.25		Intradermal at disc level
Hong et al. [33] (2009)	1	BV (4,000:1)	1.00	Korean Pharmacopuncture Institute	Tender point	VNRS 8 → 3; ODI 35 → 21
Lee et al. [34] (2010)	1	BV (4,000:1)	1.00	Korean Pharmacopuncture Institute	Ah-Shi point	NRS 9 → 3; SLRT 60/20 → 70/70
	1					NRS 8 → 1; SLRT 30/90 → 45/90
	1					NRS 9 → 3
Jung et al. [35] (2013)	208	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2	NRS 5.6 ± 2.3 → 2.8 ± 1.8; ODI 45.5 ± 20.0 → 27.2 ± 14.1; SLRT 61.3 ± 23.0 → 73.2 ± 14.0; Improvement in Lumbar ROM
		BV (10,000:1)	0.20		BL23, BL 24, BL25, BL31, BL32, BL33, BL34, GB30
Kwon et al. [36] (2020)	1	Shinbaro2	4.00	Jaseng Hospital of Korean Medicine	Facet joint	NRS 9 → 7; ODI 70 → 70
			0.20		Ah-Shi point , EX-B2, BL23, BL24, BL25, BL54
Nam et al. [37] (2011)	44	BV (10,000:1)	0.40	Jaseng Hospital of Korean Medicine	Intradermal at disc level	VNRS 6.24 ± 2.56 → 2.29 ± 1.25; ODI 54.84 ± 22.01 → 31.36 ± 12.75
		Hwangryunhaedok	1.00		Ah-Shi point
Kim et al. [38] (2014)	46	Hwangryunhaedok	0.10	Jaseng Hospital of Korean Medicine	Supraspinous lig., BL23, BL24, BL25, BL26	NRS 5.84 ± 2.58 → 2.12 ± 1.74; SF-36 49.65 ± 10.04 → 57.90 ± 11.56
Kwon et al. [39] (2009)	35	BV (8,000:1)	0.10	Korean Pharmacopuncture Institute	Intradermal at disc level, BL23, BL24, BL25, BL26, GV3, GV4	VAS 7.31 ± 1.44 → 1.49 ± 1.99; ODI 39.43 ± 15.6 → 15.31 ± 12.0; Comparison of MRI images 42.86% improved
Kim et al. [40] (2014)	1	Shinbaro	0.30	Jaseng Hospital of Korean Medicine	EX-B2	NRS 8 → 4; ODI 42.22 → 22.22; SLRT 40/40 → 40/60; EQ-5D 12 → 10
		BV (10,000:1)	0.30		GB30
Woo et al. [41] (2010)	1	Hwangryunhaedok	1.00	Korean Pharmacopuncture Institute	Tender point	NRS 7 → 0; ODI 15 → 8; SLRT 70/20 → 90/90; Improvement in Lumbar ROM
		Hominis Placenta	1.00
Shin et al. [42] (2011)	20	BV (4,000:1)	1.00	Korean Pharmacopuncture Institute	EX-B2	VAS 10 → 3.50 ± 1.76
	14				Multifidus m.	VAS 10 → 4.43 ± 3.41
Choi et al. [43] (2020)	1	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2, Ah-Shi point	NRS 6 → 2; ODI 75.56 → 31.11; Improvement in Lumbar ROM
Baek et al. [44] (2013)	1	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	Ah-Shi point	NRS 7 → 1; ODI 52 → 30; SLRT 60/80 → 70/90
Seo et al. [45] (2018)	1	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2, Tender point	NRS 5 → 2; EQ-5D 0.676 → 0.7
Kim et al. [46] (2015)	72	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2	NRS 5.89 ± 2.00 → 3.42 ± 1.87; ODI 46.69 ± 19.25 → 35.69 ± 16.67; EQ-5D 0.63 ± 0.26 → 0.71 ± 0.20
Hwang et al. [47] (2018)	1	CS25	0.15	Namsangcheon External Herbal Dispensary	EX-B2, Ah-Shi point, GV3	NRS 7 → 1; ODI 53.33 → 6.67; RMDQ 12 → 2
		BV (NR)	0.04	Jaseng Hospital of Korean Medicine
	1	CS25	0.15	Namsangcheon External Herbal Dispensary		NRS 7 → 2; ODI 60 → 24.44; RMDQ 9 → 4
		BV (NR)	0.04	Jaseng Hospital of Korean Medicine
Youn et al. [48] (2008)	20	BV (8,000:1)	0.10	Korean Pharmacopuncture Institute	Intradermal at disc level, BL23, BL24, BL25, BL26, GV3, GV4	VAS 4.67 ± 2.76 → 3.42 ± 2.17; ODI 21.55 ± 8.41 → 15.35 ± 8.18; SF-36 30.85 ± 13.86 → 41.15 ± 14.25
Lee et al. [49] (2015)	1	Muscle relaxation	2.00	Jaseng Hospital of Korean Medicine	EX-B2	NRS 7 → 2; ODI 37.78 → 20
	1					NRS 7 → 2; ODI 40 → 20
	1					NRS 8 → 1; ODI 73.33 → 35.56
	1					NRS 8 → 7; ODI 86 → 70
Youn et al. [50] (2008)	34	BV (8,000:1)	0.10	Korean Pharmacopuncture Institute	Intradermal at disc level, BL23, BL24, BL25, BL26, GV3, GV4	VAS 5.05 ± 2.47 → 1.98 ± 3.15; ODI 38.24 ± 14.74 → 12.53 ± 17.40
Kim et al. [51] (2021)	1	Shinbaro	2.00	Jaseng Hospital of Korean Medicine	Facet joint	NRS 7 → 0; ODI 0.349 → 0.677; EQ-5D 75.56 → 24.44
			0.20		Tender point
Park et al. [52] (2013)	12	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2, GB30	VAS 4.50 ± 2.32 → 2.99 ± 2.05; ODI 51.88 ± 21.74 → 24.46 ± 10.12; PRS 71.67 ± 24.34 → 45.58 ± 20.68
	10	BV (100,000:1)	1.00			VAS 4.70 ± 2.36 → 2.80 ± 1.42; ODI 49.02 ± 15.05 → 19.74 ± 7.55; PRS 80.90 ± 26.99 → 43.2 ± 21.41
Kim et al. [53] (2004)	50	Scolopendrid	3.00	Korean Pharmacopuncture Institute	Intradermal at disc level, EX-B2, BL25, BL26, BL28, GV3	Mean ΔVAS 6.90 ± 1.45; Mean ΔODI 0.34 ± 0.20; Mean ΔSLRT 0.85 ± 0.23; Improvement in Lumbar ROM
Kim et al. [54] (1999)	22	BV (2,000:1)	0.10	Korean Pharmacopuncture Institute	BL24, BL25, BL26, BL27, GB30, GV3	Self-reported questionnaire
Park et al. [55] (2003)	70	Scolopendrid	0.50	Korean Pharmacopuncture Institute	Ah-Shi point	VAS 10 → 7.25; Mean ΔDITI 0.34; Improvement in SLR ROM
Chung et al. [56] (2003)	24	BV (25,000:1)	0.05	Yumil Farm, Hwasun, Korea	Intradermal at disc level, GV3, GV4	VAS 76.58 ± 14.81 → 16.69 ± 16.77; ODI improved; Improvement in Lumbar ROM
Kim et al. [57] (2005)	30	BV (2,000:1)	0.25	Korean Pharmacopuncture Institute	EX-B2, GB30	VAS 10 → 0.18 ± 0.07; ODI imrpoved
Oh et al. [58] (2014)	1	Shinbaro	2.00	Jaseng Hospital of Korean Medicine	EX-B2, BL25, BL26, GV3, GV4, GV5	NRS 4 → 2; ODI 23 → 17
	1					NRS 2 → 1; ODI 26 → 18
	1					NRS 9 → 5; ODI 32 → 28
Jang et al. [59] (2008)	1	Scolopendrid	1.00	Korean Pharmacopuncture Institute	EX-B2, BL25, BL26	ODI 80 → 44; PRS 84 → 36
Jun et al. [60] (2011)	10	Shibaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2	NRS 7.80 ± 1.48 → 3.50 ± 2.01; ODI 60.00 ± 20.11 → 38.80 ± 18.81
		Hwangryunhaedok	0.10		BL23, BL25
	10	Hwangryunhaedok	0.10		BL23, BL25	NRS 6.50 ± 1.50 → 4.50 ± 1.43; ODI 50.60 ± 27.13 → 43.00 ± 18.74
Jun et al. [61] (2012)	24	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2	NRS 5.92 ± 1.31 → 3.08 ± 1.17; ODI 41.67 ± 17.35 → 20.17 ± 18.22
		BV (10,000:1)	0.10		BL23, BL25
Huh et al. [62] (2016)	40	Shinbaro	2.00	Jaseng Hospital of Korean Medicine	Facet joint	NRS 6.45 ± 1.85 → 1.20 ± 0.83; ODI 41.25 ± 15.97 → 13.15 ± 9.14
Shin et al. [63] (2015)	60	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	Erector spinae	NRS 7.87 ± 1.20 → 3.80 ± 1.42; ODI 34.57 ± 7.47 → 22.30 ± 9.62
Lee [64] (2014)	58	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	EX-B2	NRS 7.80 ± 1.21 → 3.57 ± 1.10; ODI 34.77 ± 7.41 → 21.90 ± 8.87
Kim et al. [65] (2016)	12	Shinbaro	2.00	Jaseng Hospital of Korean Medicine	Intradermal at disc level, Tender point	VNRS 5.58 ± 1.62 → 2.91 ± 1.56; ODI 48.87 ± 18.72 → 28.57 ± 15.05; SLRT 57.5 ± 26/49.58 ± 27.9 → 60.83 ± 21.5/55.00 ± 25; EQ-5D 0.58 ± 0.31 → 0.80 ± 0.12; Improvement in Lumbar ROM
		BV (10,000:1)	2.00
Namgoong et al. [66] (2020)	1	Shinbaro	0.25	Jaseng Hospital of Korean Medicine	Supraspinous lig., EX-B2	NRS 7 → 3; ODI 48 → 11; EQ-5D 0.399 → 0.841
	1					NRS 7 → 3; ODI 86 → 37; EQ-5D 0.316 → 0.763
	1					NRS 9 → 3; ODI 66 → 28; EQ-5D 0.247 → 0.73
	1					NRS 6 → 1; ODI 33 → 16; EQ-5D 0.493 → 0.795
	1					NRS 9 → 3; ODI 86 → 16; EQ-5D 0.316 → 0.841
Choi et al. [67] (2003)	70	Scolopendrid	3.00	Korean Pharmacopuncture Institute	Intradermal at disc level, EX-B2, BL25, BL26, BL28	Mean ΔODI 11.4; DITI 57.46 ± 15.80 → 46.02 ± 15.25; Improvement in Lumbar & SLR ROM
Ryu and Kim [68] (2018)	1	Shinbaro	0.20	Jaseng Hospital of Korean Medicine	EX-B2	NRS 7 → 1; ODI 74 → 37.78
Kim et al. [69] (2010)	1	BV (10,000:1)	0.30	Korean Pharmacopuncture Institute	BL23, GV4	NRS 8 → 3
		Hominis Placenta
Seo et al. [70] (2015)	1	BV (20,000:1)	1.00	Jaseng Hospital of Korean Medicine	Ah-Shi point	NRS 7 → 3; ODI 16 → 7
Huh et al. [71] (2014)	40	Shinbaro	2.00	Jaseng Hospital of Korean Medicine	Facet joint	NRS 7.00 ± 1.62 → 3.10 ± 2.05; ODI 20.65 ± 7.05 → 13.40 ± 5.35
Yun et al. [72] (2023)	1	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	Tender point, EX-B2	NRS 7 → 3; EQ-5D 0.487 → 0.681
Choi et al. [73] (2021)	1	BV (10,000:1)	0.10	Korean Pharmacopuncture Institute	BL22, BL23, BL24, BL25, BL26	NRS 5 → 1; ODI 39 → 9; EQ-5D 0.206 → 0.663
Lee et al. [74] (2019)	1	SBV1	0.10	Korean Pharmacopuncture Institute	EX-B2	VAS 5 → 1; ODI 10 → 7; EQ-5D 0.766 → 0.913
	1	Aconitum	0.10		EX-B2, Quadratus Lumborum	VAS 7 → 1; ODI 24 → 20; EQ-5D 0.513 → 0.723
	1	SBV1	0.10		EX-B2	VAS 7 → 3; ODI 22 → 15; EQ-5D 0.444 → 0.559
Park et al. [75] (2018)	1	SBV	0.10	AJ Herbal Dispensary	Intradermal at disc level, EX-B2	NRS 8 → 1; Improvement on MRI
Shin et al. [76] (2016)	524	Shinbaro	1.00	Jaseng Hospital of Korean Medicine	Ah-Shi point , EX-B2	NRS 6.0 ± 2.4 → 2.82 ± 1.88; ODI 48.6 ± 20.74 → 29.15 ± 15.00
		BV (10,000:1)	0.20		Ah-Shi point

BV, Bee Venom; SBV, Sweet Bee Venom; eBV, Essential Bee Venom; NRS, Numeric Rating Scale; VAS, Visual Analogue Scale; VNRS, Verbal Numeric Rating Scale; ODI, Oswestry Disability Index; SLRT, Straight Leg Raise Test; MRI, magnetic resonance imaging; ROM, range of motion; RMDQ, Roland-Morris Disability Questionnaire; SF-36, Short Form (36) Health Survey; PRS, Pain Relief Scale; PI-LL, pelvic incidence minus lumbar lordosis; SF-MPQ, Short-Form McGill Pain Questionnaire; FIM, Functional Independence Measure; MMT, manual muscle testing; EQ-5D, EuroQol-5 Dimensions.

The concentration of the Bee Venom was determined based on the maximum concentration standard. Doses were determined based on the maximum dose standard.

The distribution of patients by the number of herniated disc levels is shown in Table 2. Among 1,783 patients, most studies did not report the exact number of affected disc levels (NR, n = 1,486, 83.3%). Among cases with available information, LDH at a single disc level was most common (n = 231, 13.0%), followed by two levels (n = 45, 2.5%), three levels (n = 17, 1.0%), four levels (n = 3, 0.2%), and five levels (n = 1, 0.1%).

Table 2.

Distribution of patients according to the number of herniated disc levels across included studies

Number of affected disc levels	Number of Patients (n)	Percentage (%)
1 level	231	13.0%
2 levels	45	2.5%
3 levels	17	1.0%
4 levels	3	0.2%
5 levels	1	0.1%
Not reported (NR)	1,486	83.3%
Total	1,783	100.0%

The distribution of LDH levels is presented in Table 3. The L4-5 level was most frequently affected (n = 186, 10.0%), followed by L5-S1 (n = 135, 7.2%). Other levels were rarely involved, and 1,486 cases (79.5%) lacked information on LDH level. When herniation occurred at multiple levels in a single patient, each affected level was counted separately.

Table 3.

Distribution of herniated disc levels across included studies

LDH level	n	%
T11/T12	1	0.1%
L1/L2	5	0.3%
L2/L3	12	0.6%
L3/L4	44	2.4%
L4/L5	186	10.0%
L5/S1	135	7.2%
Not reported (NR)	1,486	79.5%
Total	1,869	100.0%

When herniation was present at multiple levels in a single patient, each affected level was counted separately.

Stage of disc herniation was reported in 697 of 1,783 patients (39.1%), while the remaining 1,086 patients (60.9%) lacked sufficient information for classification (Table 4). Among patients with specified stages, protrusion was most common (n = 307, 17.2%), followed by extrusion (n = 206, 11.6%), bulging (n = 59, 3.3%), and sequestration (n = 10, 0.6%). In addition, 115 patients (6.5%) presented with mixed stages involving two or more types.

Table 4.

Distribution of patients according to stage of lumbar disc herniation (LDH) across included studies

Stage of disc herniation	Number of patients (n)	Percentage (%)
Bulging	59	3.3%
Protrusion	307	17.2%
Extrusion	206	11.6%
Sequestration	10	0.6%
Mixed*	115	6.5%
Not reported (NR)	1,086	60.9%
Total	1,783	100.0%

*Patients presenting with two or more stages of herniation were classified as “mixed.”

We identified 10 types of PP (Bee Venom [BV], Shinbaro, Scolopendrid, Soyeom, Muscle Relaxation, Hwangryunhaedok, Hominis Placenta, Ouhyul, CS25, and Aconitum).

Shinbaro PP, derived from traditional herbal prescriptions, modulates inflammatory pathways by suppressing cytokines such as TNF-α and IL-1β and downregulating matrix-degrading enzymes, contributing to disc preservation in degenerative models [77]. Soyeom PP exerts anti-inflammatory effects by inhibiting the NFκB signaling pathway, thereby reducing inflammatory mediator expression in joint tissues [78]. Scolopendrid PP, containing extracts from Scolopendra subspinipes, has demonstrated potential in alleviating neuropathic pain by regulating neuroinflammatory responses and modulating nociceptive thresholds [79]. Muscle Relaxation PP alleviates muscular tension and improves joint mobility through its myorelaxant properties [80]. Hwangryunhaedok PP, based on a classic detoxifying formula, exhibits anti-inflammatory and heat-clearing actions, and is frequently applied in pain conditions associated with heat or toxin accumulation [81]. Hominis Placenta PP supports recovery in chronic inflammatory states via immunomodulatory and tissue-regenerative properties [82]. Ouhyul PP, formulated to resolve blood stasis, aims to enhance peripheral circulation and alleviate congestion [83]. Aconitum PP, prepared from Aconitum ciliare Decaisne extracts, has been studied for toxicity and safety in repeated-dose animal experiments [84]. Lastly, CS25 PP, a CS formulation manufactured at an external herbal dispensary, is described in the literature as an immunomodulatory preparation with strong analgesic properties, although its precise herbal composition has not been disclosed [85].

PP doses ranged from 0.04 cc to 6.00 cc across all included studies. Injection points encompassed disc sites (L3-4, L4-5, L5-S1, and others); intradermal and facet joint injections at the disc level; Ah-Shi points (Ah-Shi point, and tender point); muscles (quadratus lumborum, erector spinae, and multifidus); supraspinous ligament; and acupoints (EX-B2, GB30, BL22, BL23, BL24, BL25, BL26, BL27, BL31, BL32, BL33, BL34, BL54, GV3, and GV4). Facet joint injections were performed with MRI guidance to confirm the anatomical structures and depth before needle insertion.

The sixty-three studies were published from 1999 to 2023 (Fig. 2). During the 2000s, research primarily focused on animal-derived PP, such as BV and Scolopendrid, but following the development of Shinbaro, studies on this formulation increased markedly. Among the animal-derived PP, BV has been consistently investigated, and since the 2010s, the range of PP types used in research has continued to broaden. To characterize these trends, we analyzed the distribution of publications by PP type. A total of 34 studies investigated BV, while 29 studies examined Shinbaro. Scolopendrid was reported in 5 studies, Hwangryunhaedok in 4, and Soyeom and Hominis placenta in 2 each. Muscle Relaxation, Ouhyul, CS25, and Aconitum were reported only once, respectively. Compared with the predominance of BV and Shinbaro, studies on other types of PP were scarce (Table 5).

Figure 2.

Number of included studies by year of publication. BV, Bee Venom (includes SBV [Sweet BV] and eBV [Essential BV]). When a study reported more than one PP type, each type was counted separately.

Table 5.

Number of studies by type of pharmacopuncture (PP)

Type of PA	Number of studies	Percentage (%)
BV	34	42.5%
Scolopendrid	5	6.2%
Shinbaro	29	36.2%
Soyeom	2	2.5%
Hwangryunhaedok	4	5.0%
Hominis Placenta	2	2.5%
Muscle relaxation	1	1.2%
Ouhyul	1	1.2%
CS25	1	1.2%
Aconitum	1	1.2%

BV, Bee Venom (includes SBV [Sweet BV] and eBV [Essential BV]).

When a study reported more than one PP type, each type was counted separately.

Given the high frequency of BV and Shinbaro use across studies, we further examined the distribution of injection doses for these two formulations (Fig. 3). When a single PP type was administered at multiple doses within the same study, each dose was counted separately. For BV (n = 35), the largest proportion of studies used a dose of 0.10 cc (31.4%), followed by 1.00 cc (22.9%). For Shinbaro (n = 31), the majority used 1.00 cc (48.4%), followed by 2.00 cc (16.1%).

Figure 3.

Distribution of injection doses for Bee Venom (BV) and Shinbaro. When a PP type was administered at more than one dose within the same study, each dose was counted separately.

Outcome measures were broadly categorized as pain, functional disability, quality of life, and imaging or physical examination. Pain intensity was most often assessed using the Visual Analogue Scale (VAS), Numeric Rating Scale (NRS), or Verbal Numeric Rating Scale (VNRS), while qualitative aspects were measured with the Short-Form McGill Pain Questionnaire (SF-MPQ) and Pain Relief Scale (PRS). Functional disability was primarily evaluated with the Oswestry Disability Index (ODI) and Roland-Morris Disability Questionnaire (RMDQ), in addition to objective parameters such as range of motion (ROM), manual muscle testing (MMT), and the Functional Independence Measure (FIM). Health-related quality of life was measured using the Short-Form 36 Health Survey (SF-36) and EuroQol-5 Dimensions (EQ-5D). Imaging outcomes included MRI for assessing disc morphology, pelvic incidence minus lumbar lordosis (PI–LL) for evaluating spinal alignment, and digital infrared thermographic imaging (DITI) for analyzing thermal distribution patterns associated with inflammation. In some studies, the Straight Leg Raise Test (SLRT) was used as a diagnostic and functional indicator. Collectively, these measures reflect the multidimensional assessment of lumbar disc herniation in clinical research.

Across studies, outcome measures were most frequently reported for ODI (n = 45), NRS (n = 37), VAS (n = 17), and SLRT (n = 15), while other measures—including ROM (n = 14), EQ-5D (n = 10), VNRS (n = 4), DITI (n = 4), SF-36 (n = 2), RMDQ (n = 2), and PRS (n = 2)—were reported less often. Single reports were noted for SF-MPQ, FIM, MMT, and PI–LL, with imaging outcomes primarily based on MRI in three studies. Across these measures, pain intensity consistently improved, as reflected in reductions in NRS, VAS, and VNRS, while functional disability declined, evidenced by lower ODI and RMDQ scores. Physical function improved according to ROM, SLRT, MMT, and FIM. For SLRT, the more restricted value across both legs was used to ensure consistency with clinical interpretation, with overall results demonstrating improvement. Health-related quality of life tended to increase, as measured by EQ-5D and SF-36. To maintain methodological transparency, only outcome measures with clearly extractable numeric values were included in the frequency count. When outcomes were reported bilaterally, the lower (more restricted) value was used for SLRT, whereas for scales presented in different units (e.g., ODI reported as both percentage and decimal), only the direction of change was interpreted, and direct numerical comparisons were avoided. Outcomes described qualitatively as ‘improved’ without quantitative values (e.g., ROM in some studies) were counted as frequency mentions but excluded from pooled numeric summaries.

3. Outcomes

1) Dose of BV by injection point

An inverse relationship was observed between BV concentration and injection dose, with lower concentrations (higher dilutions) generally associated with larger volumes per point (Fig. 4). Two peaks in the overall distribution were observed: 0.1 cc (n = 11) and 1.0 cc (n = 8), which represented the most frequently used injection volumes across studies.

Figure 4.

Injection doses of Bee Venom (BV) according to concentration.

BV injections were analyzed by site: LDH level (intradermal, supraspinous ligament, and facet joint), Ah-Shi point (Ah-Shi point and tender point), muscles (erector spinae, multifidus, and quadratus lumborum), and acupoints (EX-B2, GB30, BL22, BL23, BL24, BL25, BL26, BL27, BL31, BL32, BL33, BL34, GV3, and GV4) (Table 6).

Table 6.

Injection doses of Bee Venom (BV) categorized by injection point

BV; Number of studies
BV dilution	NR					2,000:1			3,000:1			4,000:1			6,000:1		8,000:1		10,000:1							20,000:1			25,000:1		30,000:1		100,000:1
cc/ injection point	0.04	0.10	1.00	1.50		0.10	0.25		0.10	0.80		0.20	1.00		1.00		0.10		0.10	0.20	0.30	0.40	1.00	2.00		0.60	1.00		0.05		0.30		1.00
Intradermal		1															3		1				1	1					1
Supraspinous lig.
Facet joint
Ah-Shi point	1			2									1							1		1				1	1
Tender point	1		1	1								1	1											1
Erector spinae										1																					1
Multifidus													1
Quadratus Lumborum
EX-B2	1	2					1					1	1		1								1										1
GB30						1	1		1			1								1	1		1										1
BL22		1																	1
BL23		1							1								3		3	1	1
BL24		1				1			1								3		1	1
BL25		1				1			1								3		3	1
BL26		1				1											3		1
BL27						1
BL31									1											1
BL32									1											1
BL33									1											1
BL34									1											1
GV3	1					1			1								3												1
GV4									1								3				1								1

Doses reflect the maximum injected amount. When a study reported multiple concentrations, doses, or injection points, each was treated as an independent entry and counted separately.

In the application of BV for LDH, injections at the LDH level were predominantly administered at superficial intradermal sites, whereas deep structures, such as the supraspinous ligament and facet joint, were used less frequently, regardless of concentration. At Ah-Shi points, BV was injected across a wide range of doses, from 0.04 cc to 2.00 cc (e.g., NR 0.04 cc, n = 1; NR 1.50 cc, n = 2; 10,000:1 0.20-0.40 cc, n = 2; 20,000:1 0.60-1.00 cc, n = 2). In contrast, muscle injections were rare, with only isolated reports at the multifidus (4,000:1 1.00 cc, n = 1) and erector spinae (3,000:1 0.80 cc, n = 1; 30,000:1 0.30 cc, n = 1).

Acupoint injections were broadly distributed across the Bladder meridian (BL22-BL34), Gallbladder meridian (GB30), and Governor Vessel (GV3-GV4), and the extra point EX-B2. The most frequently reported dose was 0.10 cc, particularly at BL23-BL26 and GV3-GV4, where it appeared consistently across several concentrations (e.g., 8,000:1 0.10 cc, n = 3 each; 10,000:1 0.10 cc, BL23 n = 3, BL25 n = 3). Other injection sites showed a wide range of doses: EX-B2 (NR 0.04-0.10 cc, n = 3; 2,000:1 0.25 cc, n = 1; 4,000:1 0.20-1.00 cc, n =2; 6,000:1 1.00 cc, n = 1; 100,000:1 1.00 cc, n = 1), GB30 (2,000:1 0.10-0.25 cc, n = 2; 4,000:1 0.20 cc, n = 1; 10,000:1 0.20-1.00 cc, n = 3; 100,000:1 1.00 cc, n = 1), and GV3/GV4 (NR 0.04 cc, n = 1; 25,000:1 0.05 cc, n = 2; 8,000:1-10,000:1 0.10-0.30 cc, n = 4).

Overall, the frequency analysis indicated that intradermal and acupoint injections were the most consistently applied, with 0.10 cc emerging as the most common unit dose across multiple concentrations.

2) Dose of Shinbaro by injection point

We categorized Shinbaro injection doses according to injection points across 29 clinical studies (Table 7). High-volume injections of 4.00 cc and 6.00 cc were reported, particularly at deep structures such as the supraspinous ligament and facet joint. Specifically, supraspinous ligament injections were administered at 0.25 cc (n = 1) and 1.00 cc (n = 1), while facet joint injections were reported at 2.00 cc (n = 3), 4.00 cc (n = 3), and 6.00 cc (n = 1). Shinbaro was also frequently injected at tender points, with doses ranging from 0.10 cc (n = 1) and 0.20 cc (n = 1) to 1.00 cc (n = 4) and 2.00 cc (n = 1). At Ah-Shi points, doses of 0.20 cc (n = 1) and 1.00 cc (n = 3) were reported. Among acupoint applications, EX-B2 was the most frequently utilized site, with reported doses of 0.20 cc (n = 2), 0.25 cc (n = 2), 0.30 cc (n = 1), 1.00 cc (n = 11), and 2.00 cc (n = 1). Additional injections were reported at BL23 (0.20 cc, n = 1), BL24 (0.20 cc, n = 1), BL25 (0.20 cc, n = 1; 2.00 cc, n = 1), BL26 (2.00 cc, n = 1), GV3 (2.00 cc, n = 1), GV4 (2.00 cc, n = 1), GB30 (1.00 cc, n = 1), and the erector spinae (0.10 cc, n = 1). A single intradermal injection at 2.00 cc (n = 1) was also reported. Across these findings, 1.00 cc emerged as the most frequently employed dose across multiple injection points.

Table 7.

Injection doses of Shinbaro categorized by injection point

Shinbaro; Number of studies
cc/ injection point	0.10	0.20	0.25	0.30	1.00	2.00	4.00	6.00
Intradermal						1
Supraspinous lig.			1		1
Facet joint						3	3	1
Ah-Shi point		1			3
Tender point	1	1			4	1
Erector spinae	1
Multifidus
Quadratus Lumborum
EX-B2		2	2	1	11	1
GB30					1
BL22
BL23		1
BL24		1
BL25		1				1
BL26						1
BL27
BL31
BL32
BL33
BL34
GV3						1
GV4						1

Doses reflect the maximum injected amount. When a study reported multiple doses, or injection points, each was treated as an independent entry and counted separately.

3) Doses of other PP by injection point

Other PP formulations (Scolopendrid, Soyeom, Muscle Relaxation, Hwangryunhaedok, Hominis Placenta, Ouhyul, CS25, and Aconitum) were primarily injected at Ah-Shi points and classical acupoints (Table 8). Specifically, Scolopendrid injections were reported at intradermal sites (3.00 cc, n = 2), Ah-Shi points (0.50 cc, n = 2), EX-B2 (1.00 cc, n = 1; 3.00 cc, n = 1), BL25 (1.00 cc, n = 1; 3.00 cc, n = 2), BL26 (1.00 cc, n = 1; 3.00 cc, n = 2), BL27 (3.00 cc, n = 2), and GV2 (3.00 cc, n = 2). Soyeom was applied at EX-B2 (1.00 cc, n = 1) and BL23-BL26 (0.25 cc each, n = 4). Muscle Relaxation was reported once at EX-B2 (2.00 cc, n = 1). Hwangryunhaedok was administered at intradermal sites (1.00 cc, n = 1), supraspinous ligament (0.10 cc, n = 1), tender points (1.00 cc, n = 1), and acupoints including BL23 (0.10 cc, n = 2), BL24 (0.10 cc, n = 1), BL25 (0.10 cc, n = 2), and BL26 (0.10 cc, n = 1). Hominis Placenta was applied at tender points (1.00 cc, n = 1), BL23 (0.30 cc, n = 1), and GV4 (0.30 cc, n = 1). Ouhyul was reported once at an Ah-Shi point (0.60 cc, n = 1). CS25 was documented at Ah-Shi points (0.15 cc, n = 1), EX-B2 (0.15 cc, n = 1), and GV3 (0.15 cc, n = 1). Aconitum was reported at the quadratus lumborum (0.10 cc, n = 1) and EX-B2 (0.10 cc, n = 1). Collectively, these findings indicate that, across these formulations, injections were predominantly performed at Ah-Shi points and acupoints.

Table 8.

Injection doses of other PPs (Scolopendrid, Soyeom, Muscle Relaxation, Hwangryunhaedok, Hominis Placenta, Ouhyul, CS25, and Aconitum) categorized by injection point

Other PPs; Number of studies
BV dilution	Scolopendrid				Soyeom			Muscle relaxtion		Hwangryunhaedok			Hominis Placenta			Ouhyul		CS25		Aconitum
cc/ injection point	0.50	1.00	3.00		0.25	1.00		2.00		0.10	1.00		0.30	1.00		0.60		0.15		0.10
Intradermal			2								1
Supraspinous lig.										1
Facet joint
Ah-Shi point	2															1		1
Tender point											1			1
Erector spinae
Multifidus
Quadratus Lumborum																				1
EX-B2		1	1			1		1										1		1
GB30
BL22
BL23					1					2			1
BL24					1					1
BL25		1	2		1					2
BL26		1	2		1					1
BL27			2
BL31
BL32
BL33
BL34
GV3			2															1
GV4													1

Doses reflect the maximum injected amount. When a study reported multiple doses, or injection points, each was treated as an independent entry and counted separately.

Across all included studies, injection doses of PP ranged from 0.04 cc to 6.00 cc, with distinct usage patterns observed by formulation and injection point. For BV, an inverse relationship was noted between concentration and volume, with lower concentrations generally associated with higher injection doses per point. Nonetheless, two peaks were evident, with 0.10 cc and 1.00 cc emerging as the most frequently applied volumes. Injections were most often performed at intradermal and acupoint sites, particularly BL23-BL26, GV3-GV4, and EX-B2.

For Shinbaro, both small and large injection volumes were reported, with 1.00 cc representing the most frequent dose across diverse points. Notably, high-volume injections of 4.00-6.00 cc were applied at deep structures such as the supraspinous ligament and facet joint, while tender points and EX-B2 accounted for the majority of injections.

Other PPs-including Scolopendrid, Soyeom, Muscle Relaxation, Hwangryunhaedok, Hominis Placenta, Ouhyul, CS25, and Aconitum-were used in fewer studies and were predominantly injected at Ah-Shi points and traditional acupoints.

Taken together, these findings suggest that while a wide spectrum of concentrations and volumes has been explored, clinical practice has largely converged on injections at superficial or acupoint sites, with high-dose applications confined to limited cases involving Shinbaro or Scolopendrid.

DISCUSSION

We analyzed 63 studies investigating PP for LDH. Of the 10 identified PP types, BV and Shinbaro were the most extensively studied; BV studies date back to 1999, whereas Shinbaro publications surged after its commercial introduction around 2010. The remaining eight formulations (Scolopendrid, Soyeom, Muscle Relaxation, Hwangryunhaedok, Hominis Placenta, Ouhyul, CS25, and Aconitum) were reported less frequently.

Injections most frequently targeted EX-B2, BL acupoints (particularly BL23-BL26), and GV3-GV4, reflecting their anatomical proximity to the multifidus and erector spinae muscles. This pattern suggests that clinicians may have accounted for paraspinal muscle involvement in LDH pathology. Ah-Shi points were also widely used across multiple PP types, emphasizing their role in individualized, symptom-guided treatment strategies. In contrast, disc-level and deep structure injections, such as those targeting the supraspinous ligament or facet joint, were less frequent and predominantly observed in studies involving Shinbaro or Scolopendrid.

Dose distributions varied substantially by PP type. For BV, an inverse relationship was observed between concentration and volume, with lower concentrations (higher dilutions) typically injected at larger volumes. Despite this trend, two clear peaks were evident: 0.10 cc (n=11) and 1.00 cc (n=8) emerged as the most frequently applied doses across studies, especially at EX-B2, BL25, and GV3-GV4. This pattern likely reflects a strategy to reduce the risk of BV-related allergic reactions, including local edema and, rarely, anaphylaxis [86]. A nationwide multicenter study of over 80,000 patients confirmed that BV-related adverse events, while present, were largely mild, transient, and manageable without sequelae [87]. Consequently, most protocols used conservative starting doses with gradual escalation according to patient tolerance.

For Shinbaro, 1.00 cc was the most frequently used unit dose across injection points, followed by 2.00 cc. High-volume injections (4.00-6.00 cc) were reported exclusively at disc-level or facet joint sites, reflecting a strategy to deliver larger volumes to deep anatomical structures. In contrast, injections at acupoints or Ah-Shi points rarely exceeded 2.00 cc per site, indicating a clear distinction between superficial and deep application strategies.

Other PP formulations were used in comparatively fewer studies but exhibited consistent patterns. Most were injected at ≤ 1.00 cc per site, commonly at EX-B2, BL23-BL26, GV3-GV4, or Ah-Shi points. Scolopendrid was unique in that higher doses up to 3.00 cc were occasionally applied at disc level (e.g., BL25-27 and GV2), whereas Hwangryunhaedok and CS25 were almost exclusively injected at small doses (≤ 0.30 cc) in acupoint-based applications. These findings reinforce that, outside of BV and Shinbaro, the majority of PP interventions favor low-dose regimens targeted at superficial or classical acupuncture points.

Compared with conventional medicine, where transforaminal epidural steroid injections typically use 3-9 mL of injectate (Helm li et al., 2021) [88], PP for LDH has traditionally been injected at smaller unit doses of ≤ 1.00 cc per point. Nevertheless, our review identified several studies reporting larger volumes of 4.00 cc or even 6.00 cc were applied, particularly for Shinbaro and Scolopendrid. These high-volume injections were generally targeted at disc-level or deep structures and were associated with favorable therapeutic outcomes, suggesting that PP is not necessarily limited to low-volume strategies. Overall, the evidence suggests a spectrum of dosing practices, from small-volume injections at superficial acupoints to high-volume injections at deep anatomical sites, each guided by distinct clinical rationales.

Despite these promising findings, several limitations of this review should be acknowledged. First, the literature search was restricted to Korean and English databases, which may have excluded relevant studies in other languages. Second, inconsistencies in reporting, such as incomplete specification of injection points or heterogeneous units of measurement, posed challenges to data synthesis. Future randomized controlled trials with standardized reporting protocols and broader language inclusion will be essential to clarify the clinical significance of injection dose and point selection.

Nevertheless, this study provides the first comprehensive mapping of injection volumes and points across PP types for LDH. Our findings indicate that clinical practice is not confined to low-volume strategies but instead encompasses both small- and high-volume approaches, reflecting diverse therapeutic considerations. Developing standardized, formulation- and point-specific dosing protocols will be essential for optimizing the safety and efficacy of PP in LDH management.

CONCLUSION

This scoping review provides the first comprehensive mapping of PP practices for LDH, highlighting the heterogeneity in both dosing and injection points. The findings demonstrate that PP has been applied not only with conventional small-unit injections but also at larger volumes for deep structures, indicating a broader therapeutic scope than previously recognized. Such diversity reflects the evolving clinical landscape of PP and emphasizes the need to tailor dosing regimens to both PP type and anatomical target. Future investigations should move beyond descriptive reporting to systematically evaluate dose-related outcomes, safety profiles, and comparative effectiveness across formulations, thereby contributing to the development of optimized, standardized clinical protocols.