CAT’S CLAW, Uña De Gato (Uncaria tomentosa)


Cat’s Claw is the bark and root parts of a woody vine which grows in the “montaña” part of the Peruvian Amazon, which is the cooler, higher elevation part of the Amazon (approximately 600-1000 meters above sea level). The root of the plant, which may contain a higher percentage of some phytoactives is illegal to be collected in Peru, because it endangers the survival of the species. Another species is also known as Uña de Gato (Cat’s Claw). This species, Uncaria guianensis, grows at sea level and low altitudes, and does not contain the immune system strengthening compounds of Uncaria tomentosa, although it has the other beneficial properties. This is a cheaper more abundant species to collect and the bark from both plants is virtually indistinguishable. The easiest way to tell the two species apart is by the leaf. Uncaria tomentosa has fine hairs which grow on the underside of the leaf. Ultimately, the best insurance that you are getting the correct species of Cat’s Claw in your herbal extract is both the reputation of the Herbal company you buy from and “finger print” of the plant being sold. These will soon be available for inspection through Whole World Botanicals.

Chemical Composition of Uncaria tomentosa

The chemical compounds in Uncaria tomentosa have been analyzed and according to published research, it contains the following compounds:

Pentacyclic Oxindole Alkaloids (POA):

Uncarine F

Tetracyclic Oxindole Alkaloids (TOA):

Triterpenic Quinovic Acid Glycosides

Lipids: Phytosterols:


Oligomeric Proanthocyanidins (OPC)

The inner bark of contains up to 0.5% Pentacyclic Oxindole Alkaloids (POA). The roots and leaves contain higher levels of Pentacyclic Oxindole Alkaloids than the stem bark.

The Pentacyclic Oxindole Alkaloids of Uncaria tomentosa are primarily stereoisomers of one another and can interconvert in some conditions.

Dosage Recommendations

Traditional Use:
Typically, the indigenous people of Peru boil 20 – 30 grams of Uncaria tomentosa inner bark and/ or root in a liter of water for 30 – 60 minutes to prepare a tea. (If the tea is shredded, 30 minutes is sufficient.) This is then consumed throughout the day for several days to several months. This protocol can be used for the treatment of serious conditions.

For less serious conditions and preventative purposes, 10 grams of dried Uncaria tomentosa inner bark or root can be boiled in one liter of water to produce a tea. Drinking 2 – 3 cups of this tea is often beneficial.

The usual therapeutic dosage of Uncaria tomentosa tincture is 1 – 4 ml per day.

Viana Muller, Ph.D. 2003 This article may not be reprinted without permission from the author.