Cat's Claw (Uncaria tomentosa)
Photo: Vangeliq.petrova · CC BY-SA 4.0
- Digestive
- 5 conditions
- Licensed photo
Overview
Cat's claw is a climbing vine that can grow to 100 feet or more, with stems up to 8 inches in diameter, large glossy leaves, and sharp hooks resembling a cat's claws. Native to tropical rainforests in the central and eastern Andes, especially Peru, Ecuador, and Colombia, it has also been found in Guatemala, Costa Rica, and Panama. Indigenous people of the Amazon rainforest have used cat's claw for centuries to ward off disease, and NCCIH says it is promoted today for osteoarthritis, rheumatoid arthritis, cancer and viral infections. NCCIH says there is no conclusive evidence from studies in people to support cat's claw for any health purpose. By the early 1990s, over-collection from the wild threatened the species' survival; only sustainably sourced stem bark should be used, rather than root bark.
Traditional uses & properties
In traditional medicine cat's claw bark is used for gastric and inflammatory disorders; MSK says laboratory studies suggest it may reduce inflammation, but this has not been studied in people. It is marketed to support the body's natural defenses; MSK says compounds from cat's claw stimulated immune cells in laboratory experiments, but data in people are limited. Its constituents include pentacyclic oxindole alkaloids (POAs), triterpenoid glycosides, and tannins including epicatechin and proanthocyanidins.
Safety & precautions
Avoid during pregnancy and while trying to conceive, as cat's claw has contraceptive activity. Tetracyclic oxindole alkaloids (TOAs), present in some cat's claw, may suppress immune function. Some preparations are standardized to contain little or no TOAs. Medicines: NCCIH says there are theoretical reasons to expect interactions with blood thinners (anticoagulants and antiplatelet drugs) and with blood pressure medicines, and notes cat's claw may slow clotting, so mention it before any surgery. A 2017 systematic review found that cat's claw significantly raised levels of some HIV medicines, and LiverTox notes it inhibits the liver enzyme CYP3A4, so it could raise levels of other drugs cleared that way.
Educational reference only - not medical advice. Herbs can interact with medications. Consult a qualified healthcare provider before use. Full disclaimer.
Drug interactions
Interaction data is not available for this herb - talk to a pharmacist before combining it with any medication. A blank entry here means we have not documented interactions, not that none exist.
Habitat
Native to tropical rainforests in the central and eastern Andes, especially Peru, Ecuador, and Colombia. Also found in Guatemala, Costa Rica, and Panama. Only stem bark from ecologically sustainable sources should be used.
Sources
The interaction notes and the statements on this page that name a source were written by HerbMate from these references, which were last checked in October 2026. They are summaries, not medical advice; ask a pharmacist about your own medicines.
Traditionally used for
- Colitis8 herbs · 2 free
- Irritable Bowel Syndrome11 herbs · 2 free
- Ulcers15 herbs · 2 free
- Asthma14 herbs · 2 free
- Arthritis11 herbs · 2 free
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Frequently asked questions
What is Cat's Claw (Uncaria tomentosa) traditionally used for?
Traditional sources describe Cat's Claw (Uncaria tomentosa) as follows: In traditional medicine cat's claw bark is used for gastric and inflammatory disorders; MSK says laboratory studies suggest it may reduce inflammation, but this has not been studied in people. It is marketed to support the body's natural defenses; MSK says compounds from cat's claw stimulated immune cells in laboratory experiments, but data in people are limited. Its constituents include pentacyclic oxindole alkaloids (POAs), triterpenoid glycosides, and tannins including epicatechin and proanthocyanidins.
What safety cautions apply to Cat's Claw (Uncaria tomentosa)?
Avoid during pregnancy and while trying to conceive, as cat's claw has contraceptive activity. Tetracyclic oxindole alkaloids (TOAs), present in some cat's claw, may suppress immune function. Some preparations are standardized to contain little or no TOAs. Medicines: NCCIH says there are theoretical reasons to expect interactions with blood thinners (anticoagulants and antiplatelet drugs) and with blood pressure medicines, and notes cat's claw may slow clotting, so mention it before any surgery. A 2017 systematic review found that cat's claw significantly raised levels of some HIV medicines, and LiverTox notes it inhibits the liver enzyme CYP3A4, so it could raise levels of other drugs cleared that way.
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