Tribal people in the regions where cat's claw grows have used medicines prepared from the root bark for at least 2,000 years. They've used it to treat so many illnesses that it sounds like an amazing super drug. For example, sexually transmitted diseases, arthritis, ulcer, and cancer are all reported to be cured by cat's claw.

After these claims drew the attention of scientists in Europe, tests were able to show that ingredients in cat's claw have some potentially powerful qualities. Cat's claw reportedly has immune stimulant and anti-inflammatory activity; it may be helpful for the treatment of colds, irritable bowel syndrome, diverticulitis, or Crohn's disease. Much more research needs to be done on this plant and its medicinal properties. Still, cat's claw ranked among the top 10 herbs sold in American natural food stores by 1997.

Cat's claw is a climbing shrub with thick vines growing as long as 100 feet. It is found in the Amazon rainforest and in tropical countries in South America and Central America. Much of the cat's claw available in the United States, as well as information about it, comes from Peru.

Curved, claw-like thorns grow on the stem—that's how cat's claw got its name. Bitter, water-like liquid collects inside the stem. People in South and Central America reportedly drink this on occasion to stop hunger, thirst, and fatigue.

Cat's claw preparations are made by scraping the bark off the root of the vine. The root contains many types of plant chemicals. Some tannins also occur in the root (tannins are also found in tea). Quinovic acid glycosides help reduce inflammation and fight against some types of viruses.

Because collecting the root to get the bark kills the plant, herbalists look for other sources of these important ingredients. Right now, the inner bark of the vine seems to be a good alternative.

Both standardized and crude bark cat's claw are available. Crude bark is crushed and used to make tea. Standardized liquid or dried products are usually preferable: standardization is the quality control of herb manufacture.

If you've decided to take cat's claw, choose between one of the preparations listed below and take as directed by your health care provider or the product packaging.

Remember that because cat's claw has not been extensively researched, it is extremely important to get it from a reputable manufacturer.

Conventional Use

For treating mild stomach pains, sore throats, and colds; immune function; and minor injuries):

• Tea: 1 g root bark to 250 ml water, boil 10 to 5 minutes, cool, and strain. Drink 1 cup three times daily.
• Tincture (solution made from herb and alcohol, or herb, alcohol, and water): 1 to 2 ml two to three times daily
• Dry, encapsulated standardized extract: 20 to 60 mg daily

People who live where cat's claw grows say that it is very safe and nontoxic. However, until science has proven this, there are some precautions to keep in mind.

The American Herbal Products Association (AHPA) gives cat's claw a class 4 safety rating. This means that the AHPA doesn't have enough evidence to base a clear rating on. AHPA does, however, believe that the tannin content of cat's claw taken in high doses might cause some abdominal pain or gastrointestinal problems. Some researchers say that cat's claw should not be used in skin grafts or patients receiving organ transplants, or in patients with HIV, AIDS, or tuberculosis.

It is not to be used in children who are under three years of age. Breastfeeding and pregnant women also should not take cat's claw.

You might notice loose stools or diarrhea while taking cat's claw. This side effect is mild and tends to go away with continued use of cat's claw.

Because cat's claw can affect your immune system, do not take this herb if you are on any immunosuppressive therapies.

Cat's claw may protect against gastrointestinal damage associated with nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. Consult with your health care provider before using cat's claw if you are currently taking these medications.

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