Skip to main content

Devil's Claw

Scientific Name(s): Harpagophytum procumbens, subsp. procumbens DC. ex Meisn.
Common Name(s): Devil's claw, Grapple plant, Grapple vine, Radix Harpagophyti, Wood spider, Xwate
Drug class: Herbal products

Medically reviewed by Last updated on Jul 5, 2021.

Clinical Overview


Devil's claw is a folk remedy used for an extensive range of diseases, including arthritis and rheumatism. Clinical trials are generally supportive of its use as an anti-inflammatory and analgesic in low back pain and osteoarthritis.


Devil's claw has been studied for low back pain, muscle pain, and osteoarthritis using daily doses of crude tuber up to 9 g, 1 to 3 g of extract, or harpagoside 50 to 100 mg.


Do not use with antiarrhythmic, chronotropic, or inotropic medicines. Because of the bitterness of the preparation and consequent increase in gastric secretion, devil's claw is contraindicated in patients with gastric or duodenal ulcers.


Documented oxytocic adverse effects. Avoid use.


Use with antiarrhythmic, chronotropic, or inotropic medicines is contraindicated. See Interaction section for more detail and for other possible drug interactions.

Adverse Reactions

Rare, generally consisting of headache, tinnitus, or anorexia. A case of devil’s claw-induced hypertension has been documented.


Clinically important toxicity has not been observed in limited, short-term use.

Scientific Family

  • Pediliaceae (sesame)


Devil's claw grows naturally in the Kalahari Desert and Namibian steppes of southwest Africa. The plant is a weedy perennial bearing small, claw-like protrusions on the fruit and a strong central taproot growing up to 2 m deep. The secondary roots are used in decoctions and teas. The plant's leaves are large and grey-green in color, and it produces pink, red, or purple, trumpet-shaped flowers.1, 2 Devil's claw is also known as Uncaria procumbens and Harpagophytum burchellii Decne.


Devil's claw has been widely used among indigenous people of South Africa as a folk remedy for diseases ranging from liver and kidney disorders to allergies, headaches, and most commonly, rheumatism. Devil's claw was reportedly introduced to Europe by a German soldier in the mid-1900s, and thereafter its popularity increased among British, Canadian, and European herbalists. Devil's claw is marketed in Canada and Europe as a home remedy for the relief of arthritic diseases.1, 2, 3


The major chemical component thought to be responsible for the anti-inflammatory activity of devil's claw is harpagoside, a monoterpene glucoside. Other iridoid glycosides include procumbide, harpagide, 8-para-coumaroyl-harpagide, and verbascoside. Harpagoside is found primarily in the roots; secondary tubers contain twice as much glucoside as the primary roots. Flowers, stems, and ripe fruits are essentially devoid of the compound, while traces have been isolated from the leaves. Harpagoside can be progressively hydrolyzed to harpagid and harpagogenin. Commercial sources of devil's claw extract contain 1.4% to 2% of harpagoside.

Other constituents include carbohydrates, flavonoids (kaempferol, luteolin), aromatic acids, phytosterols, and triterpenes. High-performance liquid chromatography methods for identification have been reported.2, 4, 5

Uses and Pharmacology

Anti-inflammatory/Analgesic effects

In vitro studies are largely supportive of anti-inflammatory action. Mechanisms elucidated include inhibition of COX-2 enzymes and other proinflammatory enzymes, antioxidant activity, reductions in expression of prostaglandin PGE2, and inhibition of cysteinyl-leukotrienes.3, 4, 6, 7, 8, 9

Animal data

Most animal studies support the anti-inflammatory and analgesic effects of devil's claw extracts. Studies have included oral, intraperitoneal, and intraduodenal routes of administration, with oral use having the most negative findings. Inhibition of carrageenin-induced paw edema by devil's claw was comparable with that of phenylbutazone, indomethacin, and acetyl salicylic acid. A dose-dependent effect has also been described.3, 4, 10, 11, 12, 13, 14

Clinical data

Reviews of clinical trials have focused primarily on arthritic conditions (hip and knee) and low back pain. A meta-analysis of available data has not been conducted, possibly because of diverse methodologies.3, 4, 15, 16, 39

Few quality double-blind, placebo-controlled, or comparator randomized trials have been conducted in osteoarthritis; however, there is general support for evidence of effect in pain reduction. Other clinical studies (open-label) are also supportive. Well-designed, adequately powered studies are required before definitive statements regarding optimal dose, efficacy, and duration of therapy can be made.15, 16 The use of devil's claw in treating low back pain has been reviewed by a Cochrane group who found evidence to support a short-term reduction in pain greater than that of placebo, based on 2 low quality clinical trials.15, 39 Positive results from other less well-designed trials have been published.3, 4

Cardiac effects

Older animal studies demonstrated cardiac effects of extracts of H. procumbens, including dose-dependent reduction in blood pressure, decreased heart rate, and anti-arrhythmic activity, with mixed results or inotropic and chronotropic effects for different iridoids.17, 18, 19 Clinical studies are lacking.

Central nervous system

A study in rats showed anticonvulsant effects of an extract of H. procumbens, possibly via CNS depression and gamma aminobutyric acid neurotransmission.20 Anticholinesterase activity has also been described.21


Devil's claw has been studied for low back pain, muscle pain, and osteoarthritis using daily doses of crude tuber up to 9 g daily, 1 to 3 g of extract, and harpagoside 50 to 100 mg.3, 22, 23 Commercial preparations are inconsistent in the composition of iridoid glycosides, with some products likely to be more effective than others. Harpagoside is considered the key ingredient for anti-inflammatory effect.23

Devil's claw is not recommended for use in children due to lack of safety or clinical trial data.3 It is also not recommended for long-term use (more than 3 to 4 months) because of a lack of data.3, 24

Pregnancy / Lactation

Avoid use. Oxytocic adverse effects have been documented.2, 3 H. procumbens extract produced rhythmic contractions in isolated rat uterine tissue.25 Case reports indicate the potential to stimulate uterine contractions.26


A poorly documented case report of an interaction with warfarin manifesting as purpura exists.3, 27, 28 However, devil's claw does not affect blood eicosanoid production.29 Use with antiarrhythmic, chronotropic, or inotropic medicines is contraindicated because of decreased heart rate observed in rats and mild positive inotropic effects in rabbits in older studies.3, 18, 19, 30 Devil's claw may also potentiate antidiabetic therapy.2, 3, 4

Based on pharmacologic activity, may alter hemostasis and may be contraindicated in individuals with active bleeding (eg, peptic ulcer, intracranial bleeding). Use with caution in individuals with a history of bleeding, hemostatic disorders, or drug-related hemostatic problems; or in individuals taking anticoagulant medications, including warfarin, aspirin, aspirin-containing products, NSAIDs, or antiplatelet agents (eg, ticlopidine, clopidogrel, dipyridamole).28, 40

Screening studies report that H. procumbens is unable to inhibit cytochrome P450 enzymes and is unlikely to have any clinically relevant effect on the cytochrome system.4, 31 It is possible that devil's claw may affect multidrug P-glycoprotein (P-gp) drug transporter.32

Adverse Reactions

Rare, GI-related adverse effects have been reported in clinical trials, including mild GI upset, anorexia, and loss of taste. Rarely, unspecified serious GI events have been reported. Headache and tinnitus have been reported.33, 34, 38 Cardiovascular adverse events are theoretically possible based on older studies in rodents.34 A case of symptomatic hypertension has been documented in a 62-year-old healthy woman who consumed 500 mg/day of a product containing Devil’s claw. Blood pressure returned to normal and complaints of headache and dizziness subsided in the 2 weeks following discontinuation of the product.37

Anecdotal reports suggest devil's claw may increase stomach pH due to its bitter taste, so it should be avoided in people with gastric or duodenal ulcers.3, 35 Devil's claw should also be used with caution in patients with gallstones.2, 3 Unsubstantiated reports of possible hypoglycemic effects should be considered for diabetic patients.3 Nephrotoxicity is rare, but devil’s claw may impede P-gp excretion of toxins, which could contribute to kidney injury.36


Harpagoside has been found to be of low toxicity, with a median lethal dose of more than 13.5 g/kg in mice. Although no long-term toxicity studies have been reported, rats given oral doses of harpagoside 7.5 g/kg/day showed no clinical, hematologic, or gross pathologic changes.3, 35

Index Terms

  • Harpagophytum burchellii Decne
  • Uncaria procumbens


1. Harpagophytum procumbens. USDA, NRCS. 2017. The PLANTS Database (, July 2017). National Plant Data Team, Greensboro, NC 27401-4901 USA. Accessed July 2017.
2. Radix Harpagophyti. In: WHO Monographs on Selected Medicinal Plants. Vol. 3. Geneva, Switzerland: World Health Organization; 2007.
3. Brendler T, Gruenwald J, Ulbricht C, Basch E; Natural Standard Research Collaboration. Devil's Claw (Harpagophytum procumbens DC): an evidence-based systematic review by the Natural Standard Research Collaboration. J Herb Pharmacother. 2006;6(1):89-126.17135164
4. Grant L, McBean DE, Fyfe L, Warnock AM. A review of the biological and potential therapeutic actions of Harpagophytum procumbens. Phytother Res. 2007;21(3):199-209.17128436
5. Clarkson C, Staerk D, Hansen SH, Smith PJ, Jaroszewski JW. Identification of major and minor constituents of Harpagophytum procumbens (Devil's claw) using HPLC-SPE-NMR and HPLC-ESIMS/APCIMS. J Nat Prod. 2006;69(9):1280-1288.16989520
6. Ouitas NA, Heard CM. A novel ex vivo skin model for the assessment of the potential transcutaneous anti-inflammatory effect of topically applied Harpagophytum procumbens extract. Int J Pharm. 2009;376(1-2):63-68.19383533
7. Fiebich BL, Muñoz E, Rose T, Weiss G, McGregor GP. Molecular targets of the antiinflammatory Harpagophytum procumbens (Devil's claw): inhibition of TNFα and COX-2 gene expression by preventing activation of AP-1. Phytother Res. 2011.2207253910.1002/ptr.3636
8. Anauate MC, Torres LM, de Mello SB. Effect of isolated fractions of Harpagophytum procumbens D.C. (devil's claw) on COX-1, COX-2 activity and nitric oxide production on whole-blood assay. Phytother Res. 2010;24(9):1365-1369.20812280
9. Abdelouahab N, Heard C. Effect of the major glycosides of Harpagophytum procumbens (Devil's Claw) on epidermal cyclooxygenase-2 (COX-2) in vitro. J Nat Prod. 2008;71(5):746-749.18412394
10. Wachsmuth L, Lindhorst E, Wrubel S, et al. Micro-morphometrical assessment of the effect of Harpagophytum procumbens extract on articular cartilage in rabbits with experimental osteoarthritis using magnetic resonance imaging. Phytother Res. 2011;25(8):1133-1140.21284047
11. Uchida S, Hirai K, Hatanaka J, Hanato J, Umegaki K, Yamada S. Antinociceptive effects of St. John's wort, Harpagophytum procumbens extract and Grape seed proanthocyanidins extract in mice. Biol Pharm Bull. 2008;31(2):240-245.18239280
12. Mahomed IM, Ojewole JA. Analgesic, antiinflammatory and antidiabetic properties of Harpagophytum procumbens DC (Pedaliaceae) secondary root aqueous extract. Phytother Res. 2004;18(12):982-989.15742343
13. Inaba K, Murata K, Naruto S, Matsuda H. Inhibitory effects of devil's claw (secondary root of Harpagophytum procumbens) extract and harpagoside on cytokine production in mouse macrophages. J Nat Med. 2010;64(2):219-222.20177800
14. Catelan SC, Belentani RM, Marques LC, et al. The role of adrenal corticosteroids in the anti-inflammatory effect of the whole extract of Harpagophytum procumbens in rats. Phytomedicine. 2006;13(6):446-451.16716916
15. Gagnier JJ, van Tulder M, Berman B, Bombardier C. Herbal medicine for low back pain. Cochrane Database Syst Rev. 2006;(2):CD004504.16625605
16. Brien S, Lewith GT, McGregor G. Devil's Claw (Harpagophytum procumbens) as a treatment for osteoarthritis: a review of efficacy and safety. J Altern Complement Med. 2006;12(10):981-993.17212570
17. Occhiuto F, Circosta C, Ragusa S, Ficarra P, Costa De Pasquale R. A drug used in traditional medicine: Harpagophytum procumbens DC. IV. Effects on some isolated muscle preparations. J Ethnopharmacol. 1985;13(2):201-208.4021517
18. Circosta C, Occhiuto F, Ragusa S, et al. A drug used in traditional medicine: Harpagophytum procumbens DC. II. Cardiovascular activity. J Ethnopharmacol. 1984;11(3):259-274.6482477
19. Soulimani R, Younos C, Mortier F, Derrieu C. The role of stomachal digestion on the pharmacological activity of plant extracts, using as an example extracts of Harpagophytum procumbens. Can J Physiol Pharmacol. 1994;72(12):1532-1536.7736345
20. Mahomed IM, Ojewole JA. Anticonvulsant activity of Harpagophytum procumbens DC [Pedaliaceae] secondary root aqueous extract in mice. Brain Res Bull. 2006;69(1):57-62.16464685
21. Georgiev MI, Alipieva K, Orhan IE. Cholinesterases inhibitory and antioxidant activities of Harpagophytum procumbens from in vitro systems. Phytother Res. 2012;26(2)313-316.21721061
22. Chrubasik S. Addendum to the ESCOP monograph on Harpagophytum procumbens. Phytomedicine. 2004;11(7-8):691-696.15636187
23. Ouitas NA, Heard C. Estimation of the relative antiinflammatory efficacies of six commercial preparations of Harpagophytum procumbens (Devil's Claw). Phytother Res. 2010;24(3):333-338.19610038
24. Thanner J, Kohlmann T, Künzel O, Chrubasik S. Retrospective evaluation of biopsychosocial determinants and treatment response in patients receiving devil's claw extract (doloteffin). Phytother Res. 2009;23(5):742-744.19107732
25. Mahomed IM, Ojewole JA. Uterotonic effect of Harpagophytum procumbens DC (Pedaliaceae) secondary root aqueous extract on rat isolated uterine horns. J Smooth Muscle Res. 2009;45(5):231-239.19907121
26. Newall CA, Anderson LA, and Phillipson JD. Herbal Medicines: A Guide for Health Care Professionals. London, England: The Pharmaceutical Press; 1996: 98-100.
27. Fugh-Berman A. Herb-drug interactions. Lancet. 2000;355(9198):134-138.10675182
28. Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm. 2000;57(13):1221-1227.10902065
29. Izzo AA, Di Carlo G, Borrelli F, Ernst E. Cardiovascular pharmacotherapy and herbal medicines: the risk of drug interaction. Int J Cardiol. 2005;98(1):1-14.15676159
30. Shaw D, Leon C, Kolev S, et al. Traditional remedies and food supplements. A 5-year toxicological study (1991-1995). Drug Saf. 1997;17(5):342-356.9391777
31. Modarai M, Suter A, Kortenkamp A, Heinrich M. The interaction potential of herbal medicinal products: a luminescence-based screening platform assessing effects on cytochrome P450 and its use with devil's claw (Harpagophyti radix) preparations. J Pharm Pharmacol. 2011;63(3):429-438.21749392
32. Romiti N, Tramonti G, Corti A, Chieli E. Effects of Devil's Claw (Harpagophytum procumbens) on the multidrug transporter ABCB1/P-glycoprotein. Phytomedicine. 2009;16(12):1095-1100.19577448
33. Warnock M, McBean D, Suter A, Tan J, Whittaker P. Effectiveness and safety of Devil's Claw tablets in patients with general rheumatic disorders. Phytother Res. 2007;21(12):1228-1233.17886223
34. Vlac hojannis J, Roufogalis BD, Chrubasik S. Systematic review on the safety of Harpagophytum preparations for osteoarthritic and low back pain. Phytother Res. 2008;22(2):149-152.18236448
35. Duke JA. Handbook of Medicinal Herbs. Boca Raton, FL: CRC Press; 2002.
36. Allard T, Wenner T, Greten HJ, Efferth T. Mechanisms of herb-induced nephrotoxicity. Curr Med Chem. 2013;20(22):2812-2819.23597204
37. Cuspidi C, Sala C, Tadic M, Grassi G, Mancia G. Systemic hypertension induced by Harpagophytum procumbens (devil's claw): a case report. J Clin Hypertens (Greenwich). 2015;17(11):908-910.26094951
38. [Anonymous.] Devil's claw root: ulcers and gastrointestinal bleeding? Prescrire Int. 2013;22(144):296.24600731
39. Oltean H, Robbins C, van Tulder MW, Berman BM, Bombardier C, Gagnier JJ. Herbal medicine for low-back pain. Cochrane Database Syst Rev. 2014;(12):CD004504.25536022
40. Ernst E. Cardiovascular adverse effects of herbal medicines: a systematic review of the recent literature. Can J Cardiol. 2003;19(7):818-827.12813616


This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.