Devil’s claw isn’t banned for human use in most countries, but it is prohibited in competitive equestrian sports. The international governing body for horse sports, the Fédération Équestre Internationale (FEI), classifies its active compound, harpagoside, as a Controlled Medication Substance. If you’ve seen warnings about devil’s claw being “banned,” this is almost certainly what they’re referring to. There are also legitimate medical reasons why certain people should avoid it, which may add to the confusion.
Why It’s Banned in Horse Sports
Devil’s claw is a potent natural anti-inflammatory. It works by blocking the production of several inflammatory molecules in the body, including one called COX-2, which is the same target that common pain relievers like ibuprofen hit. It also reduces the release of key pain and inflammation signals like TNF-alpha, IL-6, and IL-1β. In short, it functions much like a pharmaceutical painkiller.
That’s exactly why equestrian authorities ban it during competition. A horse given devil’s claw could compete through pain or injury that would otherwise cause it to favor a leg, resist a jump, or show signs of distress. This creates two problems: it masks conditions that could worsen under the stress of competition, putting the horse at risk of serious injury, and it gives that horse an unfair advantage over competitors whose animals aren’t medicated.
Under FEI rules, the presence of harpagoside in a horse’s body during an event without a valid veterinary form is a rule violation. The responsibility falls entirely on the horse’s handler. In California, which has its own detailed equine medication rules, a prohibited substance administered for therapeutic purposes must be withdrawn at least 24 hours before a public competition. Devil’s claw is commonly used in equine supplements and joint formulas, so accidental violations happen when owners don’t realize a feed product contains it or don’t allow enough washout time before a show.
It’s Legal for Humans in Most Countries
Devil’s claw is widely sold as an herbal supplement across the United States, the European Union, Canada, and Australia. It is not on the UK’s official list of banned or restricted herbal ingredients for medicinal use, and it holds Traditional Herbal Registration status in several European markets for the relief of joint pain and minor muscle aches. You can buy it over the counter in most health food stores.
The confusion likely stems from how freely the word “banned” gets used online. A supplement being prohibited in horse racing is very different from it being illegal for people, but headlines rarely make that distinction.
Who Should Avoid It
While devil’s claw is legal, it does carry real medical cautions that effectively make it off-limits for certain groups. The plant contains intensely bitter compounds that stimulate stomach acid production. For anyone with a history of stomach or duodenal ulcers, this is a recognized contraindication, flagged by the European Scientific Cooperative on Phytotherapy (ESCOP) and listed in 90% of herbal medicine product information sheets reviewed in a recent pharmacology analysis.
People with gallstones (specifically stones in the bile duct) should also avoid it, as it can stimulate bile flow and potentially trigger a painful episode. Cardiovascular disease is another noted contraindication in herbal medicine references, and some sources flag high blood pressure as a concern, though the evidence there is thinner.
Interactions With Blood Thinners
One interaction worth knowing about involves warfarin and similar anticoagulant medications. Lab studies show that devil’s claw inhibits a liver enzyme called CYP2C9, which is the same enzyme responsible for breaking down warfarin. If the enzyme is suppressed, warfarin levels in the blood can rise, increasing the risk of bleeding. There is one documented clinical case where a patient taking both devil’s claw and warfarin developed purpura, a condition involving unusual bruising and bleeding under the skin. The interaction was rated “possible” on a standard causality scale.
That single case report isn’t enough to draw firm clinical conclusions, but the biological mechanism is plausible enough that experts recommend caution. If you take a blood thinner and notice unexplained bruising after starting devil’s claw, that combination is the likely explanation.
Pregnant or breastfeeding women and children are also advised to avoid devil’s claw, largely because safety data for these groups doesn’t exist rather than because harm has been documented.
Why the “Banned” Label Sticks
Devil’s claw sits in an unusual space. It’s effective enough as an anti-inflammatory that professional sports organizations treat it like a drug, yet it’s sold freely as an herbal remedy for joint pain. That contrast makes it easy for product marketers to imply it’s “so powerful it’s been banned,” which is technically true in equestrian competition but misleading everywhere else. The ban is about protecting horses from competing while medicated. It’s not a statement about the supplement being dangerous for everyday human use.