Devil's Claw
Summary
Devil's claw has a handful of back and joint pain trials. In a 197-person placebo-controlled trial, more people with flaring low back pain became pain-free on extract giving 100 mg/day harpagoside; Cochrane rates this evidence low quality (grade C). Arthritis trials compared it only with drugs (grade D). The EU allows it as a traditional remedy for minor joint pain.
Key facts
- The dried tuberous root of Harpagophytum procumbens or H. zeyheri; harpagoside is the marker compound[1][2]
- Flaring low back pain versus placebo (C); hip and knee arthritis pain versus diacerhein or meloxicam (D)[3][4][6][10]
- Extracts giving 50–100 mg harpagoside a day, or 2,610 mg/day of powdered root, for 4 weeks to 4 months[3][4][5]
- EU HMPC: traditional use for minor joint pain and mild digestive complaints; trial results too inconsistent for firm conclusions[2][1]
- None reported in the EU herbal monograph[1]
- Allergy to devil's claw or an active stomach or duodenal ulcer (EU contraindications); not recommended under 18, in pregnancy or while breastfeeding[1]
- 4 graded human outcomes on this page
- October 10, 2026
How it works
ProposedDevil's claw root contains iridoid glycosides, chiefly harpagoside. In lab and animal studies harpagoside dampens inflammatory signalling such as NF-κB at micromolar concentrations, but its oral bioavailability is poor, and how the root eases pain in people is not established.[11]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Back pain | Grade C | Improved | RCT · n = 197 · 1999 | 2 rows |
| Arthritis | Grade D | Improved | RCT · n = 122 · 2000 | 2 rows |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Pain-free days during a flare of chronic low back pain | Improved | Grade C | RCT · n = 197 · 1999 Adults with chronic low back pain in an acute flare (pain above 5/10, Germany) Form: Harpagophytum extract WS 1531 · Dose: 600 or 1,200 mg/day (50 or 100 mg harpagoside) · Duration: 4 weeks Pain-free without rescue tramadol for 5 of the last 7 days: 3 on placebo, 6 on 600 mg and 10 on 1,200 mg (P=0.027, one-tailed trend test). Subgroup findings were inconsistent; only mild, infrequent stomach symptoms were possibly linked to the extract. | 10101629 (opens PubMed)Source [3] |
| Hip and knee osteoarthritis pain and function versus diacerhein | Improved | Grade D | RCT · n = 122 · 2000 Adults with knee and/or hip osteoarthritis (France) Form: Harpadol (cryoground root powder, 435 mg capsules) · Dose: 2,610 mg/day (6 capsules) · Duration: 4 months Pain, function and Lequesne scores improved similarly with devil's claw and diacerhein 100 mg/day; the devil's claw group used less diclofenac and paracetamol-caffeine rescue and had fewer adverse events. | 11143915 (opens PubMed)Source [4] |
| Low back pain versus rofecoxib | Mixed | Grade D | Pilot RCT · n = 88 · 2003 Adults with acutely worsened chronic low back pain (Germany) Form: Doloteffin (proprietary aqueous root extract) · Dose: Daily dose providing 60 mg harpagoside · Duration: 6 weeks Pain-free and 50%-improvement counts were numerically similar to rofecoxib 12.5 mg/day with no significant differences; the authors say far larger trials are needed to show equivalence. | 12509627 (opens PubMed)Source [5] |
| Knee osteoarthritis pain and function versus meloxicam | Mixed | Grade D | RCT · n = 60 · 2021 Adults aged 40–60 with mild knee osteoarthritis (Kellgren-Lawrence grade 1–2, Iran) Form: Teltonal (Harpagophytum procumbens tablets, 480 mg) · Dose: 960 mg/day (2 × 480 mg) · Duration: 1 month (meloxicam 15 mg/day for 10 days), follow-up to 8 weeks Pain (VAS), WOMAC and Oxford Knee scores improved in both groups over time with no significant difference between devil's claw and meloxicam. | 34712343 (opens PubMed)Source [10] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Standardized root extract (e.g. WS 1531, Doloteffin), labeled by harpagoside content | Varies[3][5][8][11] | Harpagoside has poor oral bioavailability and is partly converted to active metabolites.[11] | Minor adverse events in about 3% of trial participants, mainly stomach upset; in double-blind trials not more common than with placebo.[8][3] | Low back pain trials (50–100 mg harpagoside/day) |
| Cryoground or powdered dried root (e.g. Harpadol 435 mg capsules) | Varies[4][9][1] | No human absorption data in our sources.[1] | Diarrhea in 8.1% versus 26.7% with diacerhein over 4 months.[9] | Hip and knee arthritis trial (2,610 mg/day); EU traditional dose 1,350 mg/day |
| Herbal tea (cut root infusion) | Varies[1] | No human absorption data in our sources.[1] | No trial data; the EU monograph lists stomach upset, headache, vertigo and allergic reactions for devil's claw medicines.[1] | Traditional use only (EU: 4.5 g root per day as an infusion) |
Studied doses
Doses studied in human trials ranged from 600 mg/day of extract (50 mg harpagoside) to 2,610 mg/day of powdered root, for 4 weeks to 4 months. Back pain trials dosed by harpagoside, 50–100 mg/day; the arthritis powder trial used six 435 mg capsules a day.[3][4][5][9]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Stomach or duodenal ulcer
- Active gastric or duodenal ulcer is a contraindication in the EU herbal monograph.[1]
- Gallstones
- The EU monograph advises people with gallstones to consult a physician before use.[1]
- Pregnancy and breastfeeding
- Safety has not been established; the EU monograph advises against use.[1]
- Children and teenagers
- Not established in anyone under 18 because of a lack of data.[1]
- Allergy to devil's claw
- Hypersensitivity to the root is a contraindication in the EU monograph.[1]
- Pain that lasts
- The EU advises seeing a doctor if joint pain lasts more than 4 weeks or digestive complaints more than 2 weeks.[2]
- Swollen, red or hot joints
- Joint pain with swelling, redness or fever needs a medical examination rather than self-care.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Safety
Short-term safety looks good in trials, but long-term data are missing.
- Common side effects
- Diarrhea, nausea, vomiting, abdominal pain, headache, vertigo and allergic reactions (rash, hives and facial swelling) have been reported with devil's claw medicines.[1]
- Trial data
- Across 28 clinical trials, minor adverse events affected about 3% of participants, mostly digestive; no double-blind trial found more adverse events than placebo.[8]
How to read the label
- Label dose vs clinical doseTrials dosed by harpagoside: 50–100 mg/day for back pain. A label that lists only milligrams of root or extract, with no harpagoside figure, cannot be compared with the trials.[3][5][7]
- Powder vs extractPowdered root (2,610 mg/day in the arthritis trial) and concentrated extracts (600–1,200 mg/day) are not interchangeable gram for gram.[3][4][9]
- Harpagoside dose and evidenceA 2004 systematic review found limited evidence for ethanolic extracts under 30 mg harpagoside a day in hip and knee arthritis, moderate evidence for 60 mg (powder, arthritis) and 100 mg (aqueous extract, back pain flares), and called the evidence strong for 50 mg aqueous extract in back pain flares. A later Cochrane review rated the back pain evidence low quality.[7][6]
Cost per studied dose, without the sales pitch
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Cost per studied dose
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Frequently asked questions
Does devil's claw help back pain?
Possibly, short term. In a 197-person trial more people became pain-free on extract giving 100 mg harpagoside a day than on placebo; Cochrane rates the overall evidence low quality.[3][6]
Does devil's claw help arthritis?
Hip and knee trials found similar improvement to diacerhein or meloxicam, but none had a placebo group, so the true effect size is unknown.[4][10]
How much devil's claw is used in studies?
Extracts giving 50–100 mg harpagoside a day, or 2,610 mg/day of powdered root, for 4 weeks to 4 months.[3][4][5]
Who should not use devil's claw?
People with an active stomach or duodenal ulcer, and it is not recommended in pregnancy, breastfeeding or under 18. People with gallstones should ask a doctor first.[1]
What are the side effects?
Mostly digestive upset such as diarrhea or nausea, plus occasional headache, vertigo or allergic rash. In trials these were uncommon.[1][8]
Is devil's claw approved as a medicine?
In the EU it can be registered as a traditional herbal medicine for minor joint pain and mild digestive complaints, based on long use rather than trial proof.[2]
Sources
- [1]European Union herbal monograph on Harpagophytum procumbens DC. and/or Harpagophytum zeyheri Decne., radix (final, adopted 12 July 2016). European Medicines Agency, Committee on Herbal Medicinal Products, 2016. guideline
- [2]Harpagophyti radix (devil's claw root): summary of HMPC conclusions. European Medicines Agency, 2016. fact-sheet
- [3]Effectiveness of Harpagophytum extract WS 1531 in the treatment of exacerbation of low back pain: a randomized, placebo-controlled, double-blind study.. Eur J Anaesthesiol, 1999. RCT
- [4]Harpagophytum procumbens in the treatment of knee and hip osteoarthritis. Four-month results of a prospective, multicenter, double-blind trial versus diacerhein.. Joint Bone Spine, 2000. RCT
- [5]A randomized double-blind pilot study comparing Doloteffin and Vioxx in the treatment of low back pain.. Rheumatology (Oxford), 2003. pilot-RCT
- [6]Herbal medicine for low-back pain.. Cochrane Database Syst Rev, 2014. meta-analysis
- [7]Harpgophytum procumbens for osteoarthritis and low back pain: a systematic review.. BMC Complement Altern Med, 2004. systematic-review
- [8]Systematic review on the safety of Harpagophytum preparations for osteoarthritic and low back pain.. Phytother Res, 2008. systematic-review
- [9]Efficacy and tolerance of Harpagophytum procumbens versus diacerhein in treatment of osteoarthritis.. Phytomedicine, 2000. RCT
- [10]The Efficacy of Harpagophytum procumbens (Teltonal) in Patients with Knee Osteoarthritis: A Randomized Active-Controlled Clinical Trial.. Evid Based Complement Alternat Med, 2021. RCT
- [11]Decoding the mechanistic landscape of harpagoside: From molecular targets to translational pharmacology.. Fitoterapia, 2026. review
What changed
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.
- Adversarial review pass: every evidence row re-read against its PubMed abstract; Cochrane quality ratings taken from the 2014 review abstract. Official source opened before citing: EMA HMPC EU herbal monograph (12 July 2016) and HMPC summary page. NCCIH has no devil's claw fact sheet at nccih.nih.gov/health/devils-claw (404). Industry ties: trial-author overlap disclosed in PMC520753; Cochrane senior author's former ingredient-company role from its declaration; funding for the 1999, 2000 and 2003 trials is not stated in PubMed. The Leblan (11143915) and Chantre (11185727) papers report one trial and are counted once. A 2026 review (PMID 42394971) and a 2007 Spine review (17202897) carry erratum notices and were kept out. Retraction, expression-of-concern, erratum and withdrawn checks on all 9 PMIDs: none flagged. Page set indexable. Independent browser review (4 parallel reviewers, every evidence row checked against its abstract on the Vercel preview) found: meloxicam treatment-length caveat, missing hypersensitivity, breastfeeding and 4-week self-care limit, label-guide dose nuance, facial-swelling wording and low-dose caveat; all fixed.