Cat’s Claw

image of south america where cat's claw is found

The plant, Uncaria Tomentosa, is a woody vine found in the tropical jungles of South and Central America that we call cat’s claw. The hook-like thorns on the plant appear to be similar to the claws on a cat, thus the name. The plant has been studied extensively as a medicinal plant. It has several different “cultivars” that many individuals claim to be useful for different ailments.

The indigenous people of South America have used the plant for thousands of years in their medical folklore. Some believe that it is a panacea for cancer. Ancient Chinese medicine used some species of the plant. There are even more unrelated species with the same name. This has contributed to some of the confusion about the effectiveness of cat’s claw.

Performance For Cancer

The American Cancer Society states that there is no proof that cat’s claw will treat cancer or other diseases. However, the society does admit that it is an important herb in that it MAY help.

Per the Sloan Kettering Cancer Center:

“Cat’s claw may stimulate the body’s immune system but it has not been shown to be an effective treatment for cancer or HIV.

In laboratory experiments, compounds found in cat’s claw stimulate the activity of specific immune cells known as phagocytes and T-helper cells. Cat’s claw may also be able to slow some of the processes that cause inflammation, enhance DNA repair, and may reduce certain chemotherapy side effects. Most of these effects have been observed in lab studies, with only a few small studies in humans reported.”


The contraindications are more dangerous than the possible indications for the herb. They include nausea, diarrhea, and stomach discomfort. There was a report of kidney failure in a patient with lupus. The report mentioned that an individual with Parkinson’s disease did not improve but to the contrary, his symptoms worsened.

Some Benefits

However, considering that the herb may afford some assistance to patients with active rheumatoid arthritis, for some it may be worth the risk. It also may stimulate the activity of specific immune cells.

However, more studies and research is needed to prove these claims. 

Although cat’s claw has been shown to inhibit the growth of certain cancer cells in the labs, the Sloan Kettering Institute of Cancer also denies the ability of the herb to treat cancer. The assertion that it aids in the destruction of cancer cells cannot be taken seriously until there is more research and scientific studies on the benefits of the plant.

The same situation is in relation to the claims that cat’s claw may reduce inflammation as well as stimulate the activity of specific immune cells. If these assertions were all verified, it would change the way modern medicine treats diseases including cancer.

In 1997 the supplement ranked seventh for herbal sales in the United States. This says a lot about the effectiveness of the herb or at least about its perceived benefits.


cat's claw dead end

Medical science advises against taking the herb if:

You are taking warfarin or other blood thinners: Cat’s claw may increase the risk of bruising and bleeding.

You are taking drugs that are substrates of Cytochrome P450 3A4: Cat’s claw may increase the risk of side effects from these drugs.

You are taking protease inhibitors: Cat’s claw was shown to increase the serum concentrations of atazanavir, ritonavir, and saquinavir and can increase their side effects.

You are taking immune suppressants: Cat’s claw may stimulate immune cells, which may make these drugs less effective.

You are having surgery: This is due to the potential for increased bleeding and lack of safety data.

Other evidence suggests that cat’s claw is extremely helpful in combating Lyme disease. There are numerous patients who swear that the herb has alleviated their symptoms and aided in their recovery. Scientists state that antibiotics will help to kill the bacteria that causes Lyme disease. However, they have yet to affirm that the herb cat’s claw is safe. There is much literature stating its health benefits and then again there is much stating that the herb is not only of no benefit but will worsen many of the symptoms.

Effectiveness of Cat’s Claw

The jury is out on the performance of cat’s claw. The Inca’s used the herb for a variety of ailments and for health benefits. The Amazon Indians have used its bark and root for centuries. Their main focus was for the treatment of arthritis, ulcers, and sexually transmitted diseases.

It appears that it was a useful and important herb but that knowledge is lost to us. After studying all of the literature on this particular herb, we can not in good conscience recommend it. The validity of cat’s claw may very well change after there are more studies and there is scientific evidence to verify the claims.

At the present time, the jury is out on the benefits or harm the herb may cause.

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