- Grapple plant
- wood spider
For Patients & Caregivers
There is limited proof from clinical trials that devil’s claw can reduce inflammation or relieve pain.
Devil’s claw is a root extract. It has been studied to some extent in test tubes and in animals, but its biological effects in humans are still not sorted out. In laboratory animals, devil’s claw extracts reduce inflammation and cause pain relief, and also acts as an antioxidant. One study showed possible benefits for relieving some forms of arthritis, however, another study showed that devil’s claw is not as effective as drugs such as aspirin in reducing inflammation. In rats, different doses of devil’s claw have different effects on the heart: low doses seem to cause reduced heart rate and increased strength of contraction, while high doses seem to weaken heart contractions and coronary blood flow. These effects have not been shown in humans.
- To increase appetite
No scientific evidence supports this use.
- To treat gastrointestinal disorders
No scientific evidence supports this use. Devil’s claw might increase acid production by the stomach.
- To reduce inflammation
Studies in animals show a weak anti-inflammatory activity, but studies in humans do not support this use.
- To relieve pain
Studies in animals suggest that devil’s claw can relieve pain, but there is no proof from clinical trials that this effect occurs in humans.
- To treat osteoarthritis
Studies in animals suggest that devil’s claw can reduce inflammation, but there is limited proof from clinical trials that this herb can treat osteoarthritis.
- You are pregnant.
- You are taking antacids or H2 blockers (Devil’s claw can increase the production of stomach acid and reduce the effectiveness of these medications).
- You are taking beta blockers or digoxin (Devil’s claw might interfere with these medications).
- You are taking warfarin or other blood thinners (Devil’s claw might increase the risk of bleeding).
For Healthcare Professionals
Preparations of devil’s claw root have been used as anti-inflammatory agents. It is thought that the iridoid glucosides may be responsible for the plant’s activity, but they are not active when administered separately from the whole root extract. Analysis of commercial products reveals wide variance in chemical components and the basis for chemical standardization is unknown.
An open clinical study showed that Devil’s claw may benefit patients with osteoarthritis of the hip or knee (6). A systematic review of clinical trials suggests it may also be effective in treating low back pain (7).
Devil’s claw increases gastric acid secretions and may interfere with the activity of antacids and histamine-2 blockers (e.g. ranitidine and famotidine) (3). Other possible drug interactions include increased activity of anticoagulants and cardiac and anti-arrhythmic drugs (1).
In animal studies, an aqueous extract containing chiefly harpagoside showed significant dose-dependent anti-inflammatory and analgesic effects. Harpagoside is not implicated in the anti-inflammatory action, but, along with other constituents, it does appear to be involved in the peripheral analgesic properties. Devil’s claw also has antioxidant effects by scavenging both superoxide and peroxyl in a dose dependent manner (5). The bitter iridoids are responsible for the use of the herb as a stomachic. In vitro and in vivo animal studies have shown some evidence that devil’s claw might be cardioactive. Lower doses seem to cause bradycardia and increase the strength of contraction, and high doses seem to weaken heart contractions and coronary blood flow (2).
Antacids / H2 Antagonists: Devil’s claw may reduce efficacy due to increased production of stomach acid.
Beta blockers / Digoxin: Devil’s claw may cause bradycardia and weaken heart contractions and coronary blood flow.
Anticoagulants: Devil’s claw may have additive anticoagulant activity.
Cytochrome P450 enzymes: Devil’s claw root can inhibit CYP1A2/2C8/2C9/2C19/2D6 and 3A4, and may interact with substances metabolized by these enzymes (8).