Cat’s claw has been used traditionally for osteoarthritis. In a double-blind trial, 100 mg per day of a freeze-dried preparation of cat's claw taken for four weeks was significantly more effective than a placebo at relieving pain and improving the overall condition.⁶

 

In a double-blind trial, supplementation with an extract from cat's claw (Uncaria tomentosa) for 24 weeks was significantly more effective than a placebo in reducing the number of painful joints in patients with rheumatoid arthritis. The amount used was 20 mg of extract three times per day. The extract was obtained from a specific strain of cat's claw that contains pentacyclic oxindole alkaloids, compounds that appear to influence the activity of the immune system. The extract was purified to be free of tetracyclic oxindole alkaloids, which may inhibit the beneficial effects of the other alkaloids.⁷

Substances found in cat’s claw, called oxyindole alkaloids have been shown to stimulate the immune system.⁸ However, little is known about whether this effect is sufficient to prevent or treat disease.

 

Cat’s claw is another immuno-modulating herb. Standardized extracts of cat’s claw have been tested in small, preliminary trials in people infected with HIV, showing some benefits in preventing CD4 cell counts from dropping and in preventing opportunistic infections.^9,10 Further study is needed to determine whether cat’s claw is truly beneficial for people with HIV infection or AIDS.