What is Devil's Claw?
Other Names: Harpagophytum procumbens, Grapple Plant, Wood Spider
Devil's claw is a plant native to southern Africa. Its name comes from the small hooks on the plant's fruit. The active ingredients in devil's claw are believed to be iridoid glycosides called harpagosides, which are found in the secondary root.
Most of the world's supply of devil's claw comes from Namibia, with lesser amounts coming from South Africa and Botswana.
Uses For Devil's Claw
Devil's claw has been used for thousands of years in Africa for fever, rheumatoid arthritis, skin conditions, and conditions involving the gallbladder, pancreas, stomach and kidneys.
In the early 1900's, devil's claw was brought to Europe. It is used to improve digestion, as the bitter taste of devil's claw tea is thought to stimulate digestive juices.
However, the primary use of devil's claw today is for conditions that cause inflammation and pain:
According to a study in the Journal of Ethnopharmacology, sales of devil's claw in Germany were estimated to be $30 million euros in 2001, accounting for 74% of the prescriptions for rheumatism.
Health Benefits of Devil's Claw
There is some evidence for the use of devil's claw, however one larger, randomized controlled trial found only a modest benefit.
A German study examined the use of devil's claw for slight to moderate back, neck, and shoulder muscle tension and pain. In the 4-week study, 31 people took 480 mg twice a day and 32 people took a placebo. The results showed there was a significant reduction in pain in the people taking devil's claw compared to the placebo group.
A study published in the journal Rheumatology compared a devil's claw extract providing 60 mg harpagosides a day and 12.5 mg a day of the anti-inflammatory Vioxx (now off the market) for 6 weeks in 79 patients with an acute exacerbation of low back pain. Devil's claw was as effective as Vioxx in reducing pain.
A study published in the journal Joint Bone Spine compared six 435 mg capsules of powdered devil's claw extract a day (which provides about 60 mg per day of harpagosides) with 100 mg a day of a European osteoarthritis drug called diacerhein in 122 patients with osteoarthritis of the knee or hip. After four months, devil's claw was as effective as the diacerhein at relieving pain, improving mobility, and reducing the need for back-up medication (such as anti-inflammatory and analgesic drugs). A subsequent three-year placebo-controlled study found diacerhein was ineffective at reducing osteoarthritis symptoms.
In a European Journal of Anaesthesiology 4-week study, 197 people with back pain rated at 5/10 or higher on a pain scale received a standardized daily dose of 50 mg or 100 mg harpagosides or placebo. Devil's claw seemed to reduce pain more than placebo.
Devil's claw appears to work in the same way as Cox-2 anti-inflammatory drugs such as Celebrex and also produce changes in leukotrienes, another group of molecules involved in inflammation.
Devil's claw comes in capsule, tincture, and tea form. For inflammation and pain, devil's claw is usually taken in capsule form. Based on the research, a daily dose of devil's claw should provide at least 50 mg of harpagosides per day (the amount of harpagosides in each devil's claw should be indicated on the bottle).
For indigestion and appetite loss, a tea is made by steeping 1 teaspoon of chopped or powdered dry root in 2 cups of boiling water for at least 20 minutes. It is then strained and cooled.
- Devil's claw should not be used by people with gastric or duodenal ulcers.
- People with gallstones should consult a doctor before using devil's claw.
- People with diabetes or who are taking medication that affects their blood sugar should only use devil's claw under the supervision of a qualified health practitioner. In one study, devil's claw extract resulted in reductions in blood glucose in fasted normal and diabetic animals.
- Devil's claw should not be used by people who are or may be pregnant, as it is believed to cause uterine contractions.
Possible Drug Interactions
Devil's claw has been known to trigger an allergic reaction.
Some studies have reported stomach upset, a sensation of fullness, tinnitus (ringing in the ears), and headache.
In animal studies, there is a small risk of changes in blood pressure, heart rhythm, and blood glucose. One study found that it enhanced the action of GABA in the brain and depressed the central nervous system. It is not known whether these effects may also occur in humans.