Devil's Claw (Harpagophytum procumbens): Uses, Evidence and Safety

Do not use devil's claw root products if you have an active stomach or duodenal ulcer, and ask a doctor first if you have gallstones. The European Union herbal monograph lists active gastric or duodenal ulcer as a contraindication and says people with gallstones should consult a physician before use. [1] If you take warfarin, ask the prescriber or pharmacist first: a 2000 pharmacy review listed devil's claw among products with reports of possible interactions with warfarin. [2]

Overview

Devil's claw root is the common name for the tuberous secondary root of Harpagophytum procumbens and Harpagophytum zeyheri, according to the European Medicines Agency (EMA). [3] It is used for joint and back pain and sometimes for digestive complaints. This page covers oral devil's claw root products; the related herb pelargonium is covered with devil's claw on Devil's Claw and Pelargonium.

Scientific name, plant part and species

Harpagophytum procumbens (Burch.) DC. ex Meisn. is the accepted name, in the family Pedaliaceae, and Harpagophytum zeyheri Decne. is a separate accepted species. [4] [5] The part used is the secondary tuber (root). A 2012 review says the two species are used interchangeably, that H. procumbens is the favored species of commerce, and that its raw material is often intentionally adulterated with H. zeyheri, which may affect how well poorly controlled products work. [6]

Traditional use

This is tradition, not proof. The 2012 review describes devil's claw as an important traditional medicine growing in the Kalahari region of southern Africa, used as a general health tonic and for arthritis, pain, fever, ulcers and boils; its authors held a focus group with communities in Botswana to understand local uses. [6] It lists further local uses including indigestion, urinary infections, postpartum pain, sprains and sores. [6] For the wider context see African herbal medicine. In the European Union, the herbal committee (HMPC) accepted devil's claw root for minor joint pain, mild digestive upset such as bloating, and temporary loss of appetite, based on traditional use of at least 30 years, not on clinical proof. [3]

What research shows

Results apply to the specific extract studied. A trial of one standardized extract does not show that a tea, powder or other capsule works the same way.

Forms and why the form matters

EMA says devil's claw root medicines are usually herbal tea or liquid and solid forms taken by mouth, and that its monograph covers comminuted or powdered root and several liquid, soft and dry extracts. [3] The trials in the Cochrane review standardized extracts to an amount of harpagoside, a root compound. [7] What amount is right for a person is for a clinician or pharmacist to decide.

Safety

• Side effects (EMA): stomach and gut symptoms (diarrhea, nausea, vomiting, abdominal pain), headache, vertigo, and allergic reactions such as rash, hives and face swelling; frequency not known. [3] [1]
• A 2008 safety review of 28 clinical trials found that adverse events in the double-blind studies were not more common than with placebo; minor events occurred in around 3% of patients, mainly in the digestive tract. It also noted a few reports of acute toxicity and no reports of chronic toxicity, and called for more long-term safety data. [9]
• Medicines: the EU monograph lists interactions as "none reported" (2016). [1] The 2000 warfarin review noted devil's claw had documented reports of potential interactions with warfarin, and cautioned that most herb-warfarin information comes from lab data, animals or single cases. [2] See how interactions work.
• Pregnancy and breastfeeding: the monograph says safety has not been established and use is not recommended. [1] See pregnancy and breastfeeding.
• Children and teens: EMA says devil's claw root medicines should be used only in adults. [3]
• Liver, kidney, older adults, surgery: the sources we read do not describe specific cautions here. That is not proof of safety. Tell the surgical team about any supplement, as described in supplements before surgery.
• When to see a doctor: EMA says to consult a doctor if joint pain lasts more than 4 weeks, or if joint pain comes with swelling, redness or fever. [3] [1]

Sourcing and conservation

The 2012 review says Namibia is the main exporter, that high demand has led to over-harvesting and sustainability concerns, and that although only the secondary tubers are used commercially, the whole plant is often destroyed in harvesting. [6] Read more on at-risk medicinal plants and conservation. Which suppliers harvest responsibly is not something the sources we read describe.

Official statements

EMA/HMPC (European Union, summary and monograph 2016): traditional herbal medicine for minor joint pain, mild digestive disorders and temporary loss of appetite in adults. [3] [1]

A clinician or pharmacist decides what is right for a particular person.