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Devil's claw is a native of South Africa, so named because of its rather peculiar appearance. Its large tuberous roots are used medicinally, after being chopped up and dried in the sun for 3 days.
Native South Africans used the herb to reduce pain and fever and stimulate digestion. European colonists brought devil's claw back home, where it became a popular treatment for arthritis.
In modern Europe, devil's claw is used to treat all types of joint pain, including osteoarthritis, rheumatoid arthritis, and gout. Devil's claw is also used for soft tissue (muscle-related or tendon-related) pain.
Like other bitter herbs, devil's claw is said to improve appetite and relieve mild stomach upset.
The evidence for devil's claw is fairly preliminary, with the largest and most well-designed studies showing marginal benefits at best. Most studies have evaluated it for treatment of arthritis.
A double-blind study compared devil's claw to the European drug diacerhein.1 Diacerhein is a member of a drug category not recognized in the United States: the so-called "slow-acting drugs for osteoarthritis" (SADOAs). Unlike anti-inflammatory drugs such as ibuprofen, SADOAs do not give immediate relief, but rather act over a period of weeks to gradually reduce arthritis pain. The supplements glucosamine and chondroitin have been proposed as natural SADOAs.
In this trial, 122 individuals with osteoarthritis of the hip and/or knee were given either devil's claw or diacerhein for a period of 4 months. The results showed that devil's claw was as effective as diacerhein, as measured by pain levels, mobility, and need for pain-relief medications (such as acetaminophen or ibuprofen). While this might seem impressive, diacerhein itself is only slightly effective,12 and, in such cases, comparative studies must use a placebo group to achieve reliable results.
Another double-blind study followed 89 individuals with rheumatoid arthritis for a 2-month period. The group given devil's claw showed a significant decrease in pain intensity and improved mobility.2 A third double-blind study of 50 people with various types of arthritis found that 10 days of treatment with devil's claw provided significant pain relief.3 A fourth study compared devil's claw against Vioxx, an anti-inflammatory drug (currently off the market).13 While it was widely reported that devil's claw was equally effective as the drug, in fact, the study was too small to produce statistically meaningful results.
Other studies have evaluated devil's claw for treatment of muscular tension and discomfort. One of these was a 4-week, double-blind, placebo-controlled trial that evaluated 63 patients with muscular tension or pain in the back, shoulder, and neck.11 The results showed significant pain reduction in the treatment group as compared to the placebo group. However, a double-blind study of 197 individuals with back pain found devil's claw marginally effective at best.4 Similarly unimpressive results were seen in a previous double-blind study of 118 people with back pain.5
We do not know how devil's claw might work. Some studies have found an anti-inflammatory effect, but others have not.6,7 Apparently, the herb does not produce the same changes in prostaglandins as standard anti-inflammatory drugs.8
A typical dosage of devil's claw is 750 mg 3 times daily of a preparation standardized to contain 3% iridoid glycosides.
Devil's claw appears to be safe, at least for short-term use. In one study, no evidence of toxicity emerged at doses many times higher than recommended.9 In a review of 28 clinical trials dating back 20 years, researchers found no instances where adverse effects were more common than those associated with a placebo. Minor adverse effects, most gastrointestinal in nature, occurred in roughly 3% of patients.14
Devil's claw is not recommended for people with ulcers. A 6-month open study of 630 people with arthritis showed no side effects other than occasional mild gastrointestinal distress. According to one case report, the herb devil's claw might increase the potential for bleeding while taking warfarin.10
Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.
1. Leblan D, Chantre P, Fournie B. 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;67:462-467.
2. Lecomte A. Harpagophytum dans l'arthrose: Etude en double insu contre placebo. Le Magazine. 1992;15:27-30.
3. European Scientific Cooperative on Phytotherapy. Harpagophyti radix (devil's claw). Exeter, UK: ESCOP; 1996-1997. Monographs on the Medicinal Uses of Plant Drugs. Fascicule 2.
4. Chrubasik S, Junck H, Breitschwerdt H, et al. 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;16:118-129.
5. Chrubasik S, Zimpfer CH, Schutt U, et al. Effectiveness of Harpagophytum procumbens in treatment of acute low back pain. Phytomedicine. 1996;3:1-10.
6. Schulz V, Hansel R, Tyler VE, eds. Rational Phytotherapy: A Physicians' Guide to Herbal Medicine. 3rd ed. Berlin, Germany: Springer-Verlag; 1998:263.
7. European Scientific Cooperative on Phytotherapy. Harpagophyti radix (devil's claw). Exeter, UK: ESCOP; 1996-1997. Monographs on the Medicinal Uses of Plant Drugs. Fascicule 2.
8. Moussard C, Alber D, Toubin MM, et al. A drug used in traditional medicine, Harpagophytum procumbens: no evidence for NSAID-like effect on whole blood eicosanoid production in human. Prostaglandins Leukot Essent Fatty Acids. 1992;46:283-286.
9. European Scientific Cooperative on Phytotherapy. Harpagophyti radix (devil's claw). Exeter, UK: ESCOP; 1996-1997. Monographs on the Medicinal Uses of Plant Drugs. Fascicule 2.
10. Shaw D, Leon C, Kolev S, et al. Traditional remedies and food supplements: a 5-year toxicological study (1991-1995). Drug Safety. 1997;17:342-356.
11. Gobel H, Heinze A, Ingwersen M, et al. Effects of Harpagophytum procumbens LI 174 (devil's claw) on sensory, motor und vascular muscle reagibility in the treatment of unspecific back pain. Schmerz. 2001;15:10-18.
12. Fidelix T, Soares B, Trevisani VM et al. Diacerein for osteoarthritis. Cochrane Database Syst Rev. 2006;CD005117.
13. Chrubasik S, Model A, Black A et al. A randomized double-blind pilot study comparing Doloteffin and Vioxx in the treatment of low back pain. Rheumatology (Oxford). 2003;42:141-148.
14. Vlachojannis J, Roufogalis BD, Chrubasik S. Systematic review on the safety of Harpagophytum preparations for osteoarthritic and low back pain. Phytother Res. 2008;22:149-152.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015