Devil's Claw

Devil's claw refers to herbal preparations made from the secondary storage tubers of Harpagophytum procumbens, and to a lesser extent the related species Harpagophytum zeyheri, members of the sesame family Pedaliaceae ^[3]. The plants grow across the sandy Kalahari and other semiarid parts of Namibia, Botswana, and the Northern Cape of South Africa, and the common name comes from the claw-like hooks that cover the ripened seed capsule ^[3].

The medicinal activity of the root is generally attributed to a group of iridoid glycosides, of which harpagoside is the best studied; harpagide and procumbide are also present, alongside phenolic acids, flavonoids, and plant sugars ^[1][4]. Commercial extracts are commonly standardized to a defined harpagoside content, and analyses have shown that the amount of this marker varies with the plant material and the extraction solvent, which complicates direct comparison between products ^[4][5].

Indigenous peoples of southern Africa have long used the bitter root for fever, pain, and digestive complaints, and the plant was brought to European attention in the early twentieth century ^[1]. In contemporary practice it is taken as a phytomedicine for rheumatic and musculoskeletal disorders, most often osteoarthritis of the hip and knee and chronic non-specific low back pain ^[1][2]. Interest has grown partly because prolonged use of non-steroidal anti-inflammatory drugs is limited by gastrointestinal, cardiovascular, and renal risks, prompting a search for gentler alternatives ^[3].

Clinical studies, including open surveillance trials and several randomized, placebo-controlled trials, suggest that standardized root extracts can produce measurable reductions in pain and stiffness in osteoarthritis and low back pain, with generally good tolerability ^[1][2]. Reviewers nonetheless caution that the overall evidence base is constrained by small sample sizes, differing formulations and doses, short follow-up, and a shortage of high-quality head-to-head comparisons with conventional analgesics ^[3][5]. The most frequently reported adverse effects are mild digestive upsets ^[2].

Devil's claw is sold in many countries as a dietary supplement or, in parts of Europe, as a registered traditional herbal medicinal product, rather than as an approved prescription drug ^[3]. It is available in numerous forms, including dried powdered root, aqueous and hydroalcoholic extracts, tablets, capsules, tinctures, and teas ^[1]. Because wild harvesting supplies most of the global trade, the species was once proposed for international protection under CITES; the listing was ultimately withdrawn after the range states adopted sustainable harvesting and management measures ^[3].

Generally well tolerated; the most common complaints are mild stomach upset and diarrhea. Because it stimulates stomach acid and gut motility, people with active ulcers or gallstones should be cautious. There is a theoretical interaction with blood thinners and with heart-rhythm or blood-pressure drugs, so check with a clinician if you take those.