Cat's claw (Uncaria tomentosa) is a woody vine native to the Amazon rainforest and other tropical areas of South and Central America. Cat's claw is named after the hook-like thorns that grow along its vine. The bark and root of this herb have been used among indigenous people of the rainforest for centuries to treat a variety of health problems including arthritis, ulcers, sexually transmitted diseases, fevers, and even cancer. Some women consumed cat's claw as a contraceptive because large doses of this herb were believed to cause temporary infertility.

Common Uses

After these claims drew the attention of scientists in Europe, tests began to demonstrate that substances in cat's claw boost the activity of the immune system, reduce inflammation, scavenge damaging particles known as free radicals, and destroy cancerous cells. Today, professional herbalists in the United States and Europe recommend cat's claw to treat inflammatory disorders such as arthritis, viral diseases such as HIV/AIDS, gastrointestinal illnesses such as Crohn's disease, ulcers, and certain cancers. Despite the purported benefits associated with cat's claw, relatively few scientific studies have investigated the safety and usefulness of this herb.

Research

In one study of 13 patients with human immunodeficiency virus (HIV) who refused to take conventional treatments, a dosage of 20 mg cat's claw per day for up to 5 months significantly increased white blood cell counts (the infection-fighting cells in the body that HIV destroys). Cat's claw was also found to boost white blood cell count in rats receiving chemotherapy. (A common side effect of chemotherapy is low white blood cell count.) In another study of 45 people with osteoarthritis of the knee, those who received cat's claw reported a significant reduction in knee pain compared to those who received placebo. Further studies are needed to confirm these preliminary findings, however. Another area that is being studied currently at Oregon Health Sciences University is the use of cat's claw for Alzheimer's disease; no information is available yet to indicate if the herb is helpful or harmful for this condition.

Cat's claw is a thorny vine that can climb as high as 100 feet. It is primarily found in the Amazon rainforest as well as tropical areas in South and Central America. Much of the cat's claw sold in the United States was grown in Peru.

Cat's claw got its name from the curved, claw-like thorns that grow on its stem. The root and bark of cat's claw are the parts used for medicinal purposes.

Cat's claw contains many types of plant chemicals that help reduce inflammation (such as tannins and sterols) and combat certain viruses (such as quinovic acid glycosides).

Cat's claw preparations are made from the root and bark of the of the cat's claw vine. The effectiveness of the root and bark vary depending upon what time of year that portion of the plant is harvested.

The bark of the cat's claw vine can be crushed and used to make tea. Standardized root and bark extracts are also available in either liquid or dried forms.

Pediatric

There are no known scientific reports on the pediatric use of cat's claw. Therefore, it is not currently recommended for children.

Adult

• Tea: 1 gram (1,000 mg) root bark to 8 ounces water, boil 10 to 15 minutes, cool, and strain. Drink 1 cup three times daily.
• Tincture (solution made from herb and alcohol, or herb, alcohol, and water): ¼ to ½ teaspoonful two to three times daily
• Dry, encapsulated standardized extract: 20 to 60 mg daily

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, contain active substances that can trigger side effects and that can interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care, under the supervision of a practitioner knowledgeable in the field of botanical medicine.

Although traditional lore indicates that cat's claw is very safe and nontoxic, the American Herbal Products Association (AHPA) gives cat's claw a class 4 safety rating which indicates a lack of scientific data to test that the herb is actually safe. In addition, the AHPA does indicate that the tannin content of cat's claw may cause some abdominal pain or gastrointestinal problems including diarrhea. The diarrhea or loose stools tend to be mild and go away with continued use of the herb.

Cat's claw should not be used by individuals with skin grafts or tuberculosis or by those receiving organ transplants. It should not be used by pregnant or breastfeeding women or by children who are under three years of age.

If you are currently being treated with any of the following medications, you should not use cat's claw without first talking to your healthcare provider.

Immunosuppressive Medications
In theory, because cat's claw may stimulate the immune system, this herb should not be used with medications intended to suppress the immune system, such as cyclosporin or other medications prescribed following an organ transplant. This theory has not been tested scientifically.

NSAIDs
Cat's claw may protect against gastrointestinal damage associated with nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen.

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