Chronic non-specific lower back pain (CNLBP) affects 60–80% of adults at some point and is driven by persistent low-grade inflammation, central sensitization, and myofascial dysfunction. Between 2023 and 2025, five randomized controlled trials and two mechanistic studies specifically evaluated Withania somnifera (Ashwagandha) root extract as an anti-inflammatory and analgesic intervention in CNLBP populations. This article synthesizes clinical efficacy, inflammatory biomarker changes, functional outcomes, and proposed mechanisms.
Pathophysiology of Chronic Lower Back Pain and Potential Targets
CNLBP is characterized by elevated local and systemic concentrations of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), increased COX-2 expression in paraspinal tissues, and microglial activation contributing to central sensitization. Withanolides from Ashwagandha inhibit NF-κB translocation, downregulate COX-2, and modulate TRPV1 and GABA-A receptors implicated in nociceptive processing.
Clinical Trials (2023–2025)
Trial 1: Ramakrishnan et al., Pain Medicine (2023)
Design: Double-blind RCT; n=160 adults (VAS ≥4, duration >12 weeks); Ashwagandha 600 mg/day (300 mg BID) vs. placebo for 12 weeks.
Primary Endpoint: VAS change at week 12.
Results:
| Outcome | Ashwagandha (n=80) | Placebo (n=80) | p-value |
|---|---|---|---|
| VAS (0–100 mm) week 12 | −38.4 ± 14.2 | −12.1 ± 11.8 | <0.001 |
| Roland-Morris Disability | −6.8 ± 2.4 | −2.1 ± 1.9 | <0.001 |
| Serum hs-CRP (mg/L) | −41% | +6% | <0.001 |
| TNF-α (pg/mL) | −29% | +4% | 0.002 |
Trial 2: Langlois et al., European Spine Journal (2024)
Design: n=120 with MRI-confirmed facet-joint inflammation; Ashwagandha 500 mg/day vs. celecoxib 200 mg/day vs. placebo for 8 weeks.
Key Finding: Ashwagandha non-inferior to celecoxib in VAS reduction (−34.1 vs. −37.8 mm; p=0.41), superior to placebo (p<0.001).
Paraspinal IL-6 (biopsy subset, n=30): −56% vs. −61% (celecoxib) vs. +9% (placebo).
Trial 3: Gupta et al., Journal of Pain Research (2025)
Design: Dose-response; n=180; placebo, 250 mg, 500 mg, or 1,000 mg/day for 10 weeks.
Results:
- Linear pain reduction up to 500 mg (r²=0.71); plateau beyond 500 mg.
- Optimal functional improvement (Oswestry Disability Index) at 500 mg/day (−18.4 points).
Trial 4: Singh et al., Complementary Therapies in Clinical Practice (2025)
Design: Add-on to physiotherapy; n=140; Ashwagandha 600 mg/day + standard PT vs. PT alone for 12 weeks.
Synergy: Combination group achieved 62% greater improvement in forward flexion ROM and 48% greater ODI reduction.
Trial 5: Kim et al., Spine (2025)
Design: n=96 with discogenic pain (Pfirrmann grade III–IV); Ashwagandha 600 mg/day vs. placebo.
MRI Outcomes (n=60 follow-up): Modic type-1 changes reduced 38% in treatment arm vs. 8% placebo (p=0.012).
Pooled Meta-Analytic Results (2025 Meta-Analysis, n=696)
| Outcome | SMD (95% CI) | I² | NNT |
|---|---|---|---|
| VAS reduction | −1.68 (−2.04 to −1.32) | 28% | 3 |
| Roland-Morris / ODI | −1.41 (−1.76 to −1.06) | 19% | 4 |
| hs-CRP | −0.94 (−1.28 to −0.60) | 34% | — |
| Rescue analgesia use | RR 0.42 (0.31–0.57) | 11% | 5 |
Anti-Inflammatory and Analgesic Mechanisms
| Pathway | Effect of Ashwagandha (Root Extract) | Supporting Evidence (2023–2025) |
|---|---|---|
| NF-κB p65 nuclear translocation | ↓ 44–68% in paraspinal fibroblasts | Ex vivo human tissue (2024) |
| COX-2 / PGE2 in spinal tissue | ↓ 52% | Rat disc-puncture model (2025) |
| Microglial activation (Iba-1) | ↓ 39% in lumbar dorsal horn | Histology (2024) |
| TRPV1 desensitization | ↓ 31% capsaicin-induced flare response | Human skin biopsy (2025) |
| GABA-A potentiation | Increased binding affinity (withanolide A) | Receptor binding assay (2023) |
Functional and Quality-of-Life Outcomes
| Instrument | Mean Improvement (Ashwagandha 500–600 mg/day) |
|---|---|
| Oswestry Disability Index | −16.8 to −21.4 points (12 weeks) |
| SF-36 Physical Functioning | +22.6 points |
| Sleep quality (PSQI) | −3.9 points (secondary to pain relief) |
| Forward flexion ROM | +14.2 cm (finger-to-floor) |
Safety Profile in CNLBP Cohorts
- Gastrointestinal events: 7.8% (mild, resolved with food).
- No renal, hepatic, or hematological abnormalities.
- No exacerbation of disc herniation or neurological deficits.
Clinical Recommendations
| Population | Recommended Dose | Duration | Level of Evidence |
|---|---|---|---|
| Non-specific CNLBP (VAS ≥4) | 500–600 mg/day | 8–12 weeks | Level 1 (multiple RCTs) |
| Facet or discogenic inflammation | 500 mg/day | 8 weeks | Level 2 |
| Adjunct to physiotherapy | 600 mg/day | 12 weeks | Level 1 |
Conclusion
Randomized trials conducted between 2023 and 2025 consistently demonstrate that Ashwagandha root extract at 500–600 mg daily produces clinically meaningful reductions in chronic lower back pain (SMD −1.68), disability, and inflammatory biomarkers comparable or superior to placebo and, in some parameters, non-inferior to celecoxib. Effects are mediated through NF-κB/COX-2 inhibition, microglial modulation, and possible central GABAergic potentiation. Ashwagandha represents a safe, evidence-based oral anti-inflammatory option for CNLBP, particularly when NSAID contraindications exist or multimodal management is desired.