What are the guidelines for using Devil's claw (Harpagophytum procumbens) extract for managing osteoarthritis or back pain?

Devil's Claw Extract for Osteoarthritis and Back Pain

Devil's claw extract is a safe option for acute exacerbations of chronic low back pain with small to moderate benefits, but it is not recommended for osteoarthritis based on current high-quality guidelines. 1

Guideline Recommendations

For Low Back Pain

• The American College of Physicians and American Pain Society (2007) state that herbal therapies including devil's claw appear to be safe options for acute exacerbations of chronic low back pain, with benefits ranging from small to moderate. 1
• Devil's claw is grouped with willow bark and capsicum as herbal alternatives with documented safety profiles 1
• A notable limitation is that many published trials were led by the same investigator, which could limit applicability of findings to other clinical settings 1

For Osteoarthritis

• The American College of Rheumatology/Arthritis Foundation (2020) does not include devil's claw in their comprehensive guideline for management of hand, hip, or knee osteoarthritis. 1
• The guideline strongly recommends against multiple herbal and dietary supplements including glucosamine, chondroitin sulfate, fish oil, and vitamin D for osteoarthritis 1
• The absence of devil's claw from this recent, high-quality guideline suggests insufficient evidence to support its use in osteoarthritis management 1

Clinical Context and Dosing

Effective Preparations

• Preparations containing at least 50 mg harpagoside (the active iridoid glycoside) in the daily dose should be used if devil's claw is prescribed. 2
• Aqueous extracts (like Doloteffin at 2400 mg daily, corresponding to 50 mg harpagoside) have been tested in clinical studies 3, 2
• The harpagoside content varies significantly between preparations, with aqueous extracts containing double the harpagoside of 60% ethanol extracts 2

Safety Profile

• Devil's claw is associated with lower risk of adverse events compared to NSAIDs and synthetic analgesics. 2
• Reported adverse effects are minimal, primarily limited to mild dyspeptic complaints and sensation of fullness 3
• Long-term safety data remain limited due to small study populations 4

Evidence Quality Concerns

Methodological Limitations

• The methodological quality of existing clinical trials is generally poor, with inadequate randomization, blinding, and statistical analysis in many studies 4
• Most trials lack important quality criteria including appropriate inclusion/exclusion criteria and validated outcome measures 4
• The concentration of research from single investigators raises concerns about generalizability 1

Conflicting Preclinical Data

• Early preclinical studies showed devil's claw was completely ineffective at reducing inflammation in standard animal models, even at doses 100 times the human dose 5
• Devil's claw failed to inhibit prostaglandin synthetase in vitro, suggesting it lacks anti-inflammatory properties of NSAIDs 5
• Despite negative preclinical data, some clinical trials have shown symptomatic benefit, suggesting mechanisms other than traditional anti-inflammatory pathways may be involved 3, 6

Practical Algorithm for Use

For chronic low back pain with acute exacerbations:

1. Consider devil's claw (minimum 50 mg harpagoside daily) as an alternative to NSAIDs in patients who prefer herbal therapy or have contraindications to NSAIDs 1, 2
2. Use for time-limited courses during acute flares rather than continuous long-term therapy 1
3. Monitor for mild gastrointestinal side effects 3

For osteoarthritis:

1. Do not recommend devil's claw as it is not supported by current high-quality guidelines 1
2. Prioritize evidence-based treatments: topical NSAIDs (strongly recommended for knee OA), exercise therapy (strongly recommended), and tai chi (strongly recommended for knee/hip OA) 1
3. If patients are already using devil's claw and perceive benefit, the low risk profile may justify continuation, but set realistic expectations about limited evidence 3, 4

Key Caveats

• The absence of devil's claw from the 2020 ACR/AF osteoarthritis guideline—which extensively reviewed herbal and dietary supplements—is significant and suggests the evidence base is insufficient for OA. 1
• Benefits, when present, are small to moderate at best 1
• Patients should understand that devil's claw is not a substitute for proven therapies like exercise, weight management, and topical NSAIDs in osteoarthritis 1