Devil’s claw is a plant native to Southern Africa whose dried root tubers are widely used as a natural remedy for joint pain, arthritis, and lower back pain. Its name comes from the small hooks covering its fruit, which are sharp and dense enough to trap animals and snag clothing. The plant belongs to the genus Harpagophytum, which includes two species, and its root has become one of the most commercially significant herbal exports from the region, primarily shipped from Namibia.
The Plant and Its Origins
Devil’s claw belongs to the sesame family (Pedaliaceae) and grows in the arid savannas of Southern Africa, particularly Namibia, Botswana, and South Africa, with some populations extending into southern Angola. The two recognized species are Harpagophytum procumbens and Harpagophytum zeyheri, distinguished mainly by the shape of their fruit and the number of seeds they produce.
The part used medicinally is the secondary root tuber, a fleshy storage root that grows off the main taproot. These tubers are harvested, sliced, and dried in the sun before being processed into powders, capsules, teas, or liquid extracts. The plant has a long history in traditional Southern African medicine, where it was used for pain, fever, and digestive complaints long before it entered the global supplement market.
How It Works Against Pain and Inflammation
The root tubers contain a group of compounds called iridoid glycosides, with harpagoside being the most studied. These compounds work through several pathways that reduce inflammation in the body. Harpagoside interacts with COX-2, the same enzyme targeted by common anti-inflammatory drugs like ibuprofen. Extracts of the root reduce COX-2 activity in a dose-dependent way, meaning higher concentrations produce stronger effects.
Beyond COX-2, devil’s claw suppresses key inflammatory signaling molecules. In lab studies, it reduced levels of TNF-alpha, interleukin-6, and interleukin-8, all of which drive the swelling, redness, and pain associated with chronic inflammatory conditions. It also blocks the activity of AP-1, a protein complex that switches on inflammatory genes. Even extracts stripped of harpagoside still showed meaningful anti-inflammatory effects, suggesting that multiple compounds in the root contribute to its activity rather than harpagoside alone.
One particularly interesting finding involves bone health. In animal models, harpagoside suppressed inflammation-driven bone loss and prevented the formation of osteoclasts, the cells responsible for breaking down bone tissue. This has drawn attention to its potential relevance for conditions like osteoarthritis, where cartilage and bone degradation go hand in hand with chronic inflammation.
Evidence for Osteoarthritis
Clinical trials have tested devil’s claw in people with osteoarthritis of the hip and knee. In one study using a standardized aqueous extract, patients experienced a 22.9% reduction in overall WOMAC scores, a widely used measure of arthritis severity that tracks pain, stiffness, and physical function. Pain specifically dropped by about 24% on the pain subscale, stiffness improved by 22%, and physical function scores improved by 23%.
Physicians evaluating those same patients noted even more pronounced improvements in clinical signs: a 45.5% reduction in pain on palpation, 35% improvement in mobility limitations, and a 25.4% reduction in joint crepitus (the grinding or crackling sensation in affected joints). Only two participants reported possible side effects, both mild digestive complaints. While this was an open-label study rather than a placebo-controlled trial, the consistency of improvement across multiple measures was notable.
Evidence for Lower Back Pain
The strongest clinical evidence for devil’s claw may be in treating non-specific lower back pain. A systematic review found strong evidence supporting aqueous extracts containing 50 mg per day of harpagoside for acute flare-ups of chronic lower back pain. In head-to-head comparisons, devil’s claw extract performed better than placebo and outperformed some conventional pain medications.
One study found no significant difference between devil’s claw and a conventional treatment approach that included NSAIDs, exercise, massage, nerve blocks, and acupuncture. In practical terms, that means the herbal extract held its own against a multi-pronged standard care regimen for people with non-radiating lower back pain. The research consistently points to non-radiating and pseudo-radiating back pain as the types most responsive to treatment.
Typical Dosages
Devil’s claw products come in several forms, and dosing depends on how the root has been processed. For crude dried root powder, the typical range is 2 to 9 grams per day. Standardized extracts, which concentrate the active compounds, are usually taken at 600 to 1,200 mg three times daily, delivering roughly 50 to 100 mg of harpagoside per dose. Most clinical trials showing benefit used aqueous (water-based) extracts standardized to at least 50 mg of harpagoside per day.
If you’re shopping for a devil’s claw supplement, look for products that state the harpagoside content on the label. Products without this standardization can vary widely in potency, making it difficult to match the doses used in research.
Side Effects and Safety Concerns
Devil’s claw is generally well tolerated, with most clinical trials reporting few adverse events. The side effects that do occur are almost exclusively digestive: mild diarrhea, nausea, or a feeling of fullness. These effects trace back to the bitter compounds in the root, which stimulate stomach acid production.
That same acid-stimulating property creates real risks for certain people. If you have gastric or duodenal ulcers, devil’s claw can worsen them or trigger new ones, and ulcers are listed as a contraindication by European regulatory bodies. People with gallstones should also use caution, since increased bile flow could cause complications. Pregnancy and breastfeeding are universally listed as contraindications across herbal medicine product labels.
Drug Interactions
Devil’s claw has the potential to interact with a broad range of medications. Lab studies show it can inhibit several liver enzymes responsible for metabolizing drugs, which could cause those drugs to build up to higher levels in the body than expected. It also affects P-glycoprotein, a transport protein that helps move drugs in and out of cells. However, the clinical significance of these interactions remains uncertain. Some researchers have found the effects too weak to matter at typical supplement doses, while others urge caution.
The medications most likely to be affected include blood thinners, certain heart medications, some antidepressants, and drugs processed by the liver’s main detoxification pathways. If you take prescription medications regularly, this is worth flagging with a pharmacist, who can check whether your specific drugs are processed through the affected pathways.