The African devil’s claw (Harpagophytum procumbens), also called devil’s claw or grapple plant, is a plant species of the family Pedaliaceae (sesame family) [1].
Devil’s claw is a medicinal plant that has been used for centuries in traditional African medicine and is today used mainly for musculoskeletal complaints such as osteoarthritis and back pain. Devil’s claw tubers were imported from South Africa to Germany in 1962. Over the years, various herbal preparations such as powders, infusions, tinctures, extracts, etc. have been produced from the root tubers of Harpagophytum procumbens (Hp) [2].
The anti-inflammatory and analgesic effect of devil’s claw is mainly attributed to the iridoid glycoside harpagoside [3]. In in-vitro and ex-vivo studies, harpagoside dose-dependently prevented the release of pro-inflammatory cytokines through inhibition of TNFα and IL-6 mRNA expression as well as the production of enzymes such as COX-2 and iNOS that are involved in inflammatory processes [4, 5]. In addition, all harpagoside extracts inhibited fatty acid amide hydrolase activity and thereby regulate the endocannabinoid system [6]. Antioxidant properties of flavonoids (fisetin, kaempferol, luteolin) and phenols contribute to the reduction of oxidative stress [7]. It has also been shown that harpagoside inhibits in vitro the osteoclast formation induced by the receptor activator of nuclear factor κB ligand (RANKL) and suppresses inflammation-related bone loss [8].
Other constituents of devil’s claw are phenylethanol glycosides (acteoside, isoacteoside), phytosterols (beta-sitosterol), triterpenes such as oleanolic acid, as well as chlorogenic acid, cinnamic acid and unsaturated fatty acids. The exact bioavailability and stability of the active substances in the human body is unknown [3].
Because of the possible anti-inflammatory effects of harpagoside, preparations containing devil’s claw are worth discussing for the treatment of rheumatic diseases.
In Germany about 115 preparations containing devil’s claw are listed; however, most of them are listed as non-medicinal products [9]. Several devil’s claw preparations are currently offered as herbal over-the-counter, pharmacy-only medicinal products [10], for example:
However, for most preparations no product information sheets / package leaflets are available. Moreover, the precise indications for the use of such devil’s claw preparations are unclear [9].
The package leaflets of the few suppliers state that the application is intended for diseases of the musculoskeletal and supporting system. According to the instructions for use of Teufelskralle-ratiopharm®, for example, adults and adolescents from the age of 12 should take 1 film tablet twice daily “for supportive treatment of degenerative disorders of the musculoskeletal system” [11].
A PubMed search for scientific articles using the keyword “African devil’s claw” returned (as of July 2025) 221 references, for the keyword “Harpagophytum procumbens” 106. Of these, 65 are clinical studies. They predominantly concern non-inflammatory-rheumatological indications such as neurological diseases, e.g. Alzheimer’s or Parkinson’s disease, as well as degenerative joint and spinal changes (such as non-specific back pain, gonarthrosis, etc.); by contrast, no clinical studies on rheumatological diseases are available.
Devil’s claw is traditionally used for the treatment of musculoskeletal complaints such as osteoarthritis [12]. The following data on the efficacy of devil’s claw are available from studies on osteoarthritis. A narrative literature review of 12 clinical studies (8 of them placebo-controlled, 4 with other therapies in the comparator arm) reports moderate evidence for the efficacy of an Hp powder containing 60 mg of harpagoside in the treatment of degenerative changes of the spine and of the hip and knee joints. Moderate evidence was likewise found for the use of an aqueous Hp extract with a daily dose of 100 mg of harpagoside in the treatment of acute exacerbations of chronic non-specific back pain; in addition, an aqueous extract of Hp with 60 mg harpagoside proved as effective in chronic non-specific back pain as 12.5 mg of rofecoxib per day [13].
In a further literature review on devil’s claw and osteoarthritis from 1966 to 2006, 14 studies for the assessment of efficacy were identified: eight observational studies; two comparative studies (one open-label, the other randomised); and four double-blind, placebo-controlled, randomised controlled trials. Many of the published studies lacked important methodological quality criteria. However, the data of the higher-quality studies suggest that devil’s claw could be effective in the relief of pain [14].
In one study, the efficacy of devil’s claw compared to an NSAID (meloxicam) with regard to pain relief and functional improvement was investigated in 60 patients with osteoarthritis of the knee. Group A consisted of daily administration of two tablets of Hp (Teltonal® devil’s claw 480 mg) (2 × 480 mg) over one month, and Group B consisted of daily administration of meloxicam (15 mg) over ten days. The visual analogue scale (VAS), Oxford Knee Scale (OKS) and the Western Ontario McMaster University Osteoarthritis Index (WOMAC) improved in both groups (p < 0.001), but no significant superiority was seen after 2 and 4 weeks of treatment [15].
A multicentre, randomised, double-blind parallel-group study lasting four months was carried out in 122 patients with hip and/or knee osteoarthritis. In it, Harpagophytum 2,610 mg per day was compared with diacerein (1,8-diacetoxy-3-carboxyanthraquinone) 100 mg per day. After four months, both groups showed clear improvements in osteoarthritis symptoms, with no significant differences in pain, functional disability or Lequesne score. However, the use of analgesics (acetaminophen-caffeine) and non-steroidal anti-rheumatic drugs (diclofenac) was significantly reduced in the Hp group, and the rate of adverse effects was also significantly lower [16].
The use of Harpagophytum in non-specific back pain has likewise been investigated. In a randomised double-blind study in 197 patients with chronic back pain (VAS > 5), two daily doses of the oral Hp extract WS 1531 (600 or 1,200 mg, containing 50 or 100 mg of harpagoside, respectively) were compared with placebo over a period of 4 weeks. The number of pain-free patients was three, six and ten in the placebo group, the Harpagophytum 600 group (H600) and the Harpagophytum 1200 group (H1200) (P = 0.027) [17].
A Cochrane analysis on the efficacy of phytotherapeutic agents in non-specific back pain included 3 additional studies on Hp: Hp preparations standardised to 50 mg or 100 mg of harpagoside are more effective than placebo for short-term pain relief in OA and can reduce the use of rescue medication (two studies, 315 participants, low-quality evidence) [18]. A further study from the Cochrane analysis with only 88 participants showed a relative equivalence of devil’s claw to 12.5 mg of rofecoxib (Vioxx®) per day, but it was of very low quality [18].
A further randomised, double-blind, placebo-controlled study examined the effect of devil’s claw in patients with muscle pain in the back, shoulder and neck regions. The verum group received in a double-blind, randomised manner over 4 weeks 2 × 480 mg/day of the Hp extract LI 174 (Rivoltan®). A total of 31 patients in the verum group and 32 in the placebo group were treated. After four weeks of treatment, marked clinical efficacy of the verum was demonstrated in the overall clinical score and in patient and physician assessments. Significant effects were shown in the VAS, the pressure algometer test and the muscle stiffness test. In the recording of antinociceptive muscle reflexes and of EMG surface activity, however, no difference from placebo was observed [19].
Devil’s claw is used mainly for the treatment of musculoskeletal pain due to nonspecific or degenerative conditions. Clinical data on treatment with devil’s claw preparations in patients with inflammatory rheumatic diseases are currently not available.
The effects of Harpagophytum constituents on inflammatory mediators do not exclude a therapeutic potential. However, systematic controlled clinical studies of Harpagophytum as monotherapy in case series with clearly defined inflammatory rheumatic diseases are not available. The direct use of devil’s claw for the treatment of inflammatory rheumatic diseases cannot currently be recommended as helpful.
Devil’s claw is generally well tolerated. However, there are documented adverse effects and limitations that should be considered when using it [20].
A systematic literature search on the safety of Hp preparations searched the OVID (MEDLINE), PubMed and Cochrane Collaboration Library databases back to 1985 for studies with Harpagophytum procumbens [21]. Twenty-eight clinical studies were identified, of which 20 reported adverse effects. In none of the double-blind studies was the frequency of adverse effects during treatment with devil’s claw higher than under placebo. Mild adverse effects occurred in about 3 % of patients, mainly gastrointestinal complaints such as nausea, diarrhoea or abdominal pain. There were some reports of acute toxicity, but no reports of chronic toxicity [21]. According to the available data, devil’s claw appears to be associated (compared with NSAIDs) with a low risk of adverse effects, but further long-term studies and larger case numbers are required for a final assessment [14].
It can be seen from the package leaflet for Teufelskralle-ratiopharm® that gastrointestinal complaints as well as dizziness and headache may occur. Hypersensitivity reactions (skin rashes, urticaria, facial oedema up to anaphylactic shock) have also been described. In insulin-dependent diabetes mellitus, an increase in blood glucose has been observed which receded after discontinuation. There are no sufficient investigations on the use of this medicinal product during pregnancy and lactation. Patients should therefore not take Hp preparations during pregnancy and lactation [11].
There are limitations in the scientific evidence. The available studies usually have small sample sizes; data on safety with long-term use, especially at higher doses, are missing. One problem is the standardisation of the preparations: the concentration of the active substance harpagoside varies between products, which makes the comparability of the studies more difficult.
Devil’s claw can be a herbal option for the relief of musculoskeletal complaints. Nevertheless, possible adverse effects, contraindications and the limited scientific evidence should be taken into account.
The scientific evidence is insufficient to recommend the prescription and use of devil’s claw preparations for patients with symptoms due to a defined inflammatory rheumatic disease. The use of devil’s claw in patients with non-specific back pain should not be discouraged if the patient wishes to use it.
Last updated: March 11, 2026