CAT'S CLAW Overview Information
Cat's claw is a plant. Two species of cat's claw, Uncaria tomentosa and Uncaria guianensis, are of primary interest for use as medicine. Uncaria tomentosa is most commonly used in the U.S., and Uncaria guianensis is typically used in Europe. Medicine is made from the root and bark. Cat's claw was ranked as the seventh most popular herb in U.S. sales in 1997. Be careful not to confuse cat's claw with cat's foot.
Cat’s claw is most commonly used for improving symptoms of both osteoarthritis and rheumatoid arthritis.
It is also used for various digestive system disorders including swelling and pain (inflammation) of the large intestine (diverticulitis), inflammation of the lower bowel (colitis), inflammation of the lining of the stomach (gastritis), stomach ulcers, hemorrhoids, and leaky bowel syndrome.
Some people use cat’s claw for viral infections including shingles (caused by herpes zoster), cold sores (caused by herpes simplex), and AIDS (caused by human immunodeficiency virus (HIV)).
Cat’s claw is also used for chronic fatigue syndrome (CFS), wound healing, parasites, Alzheimer’s disease, asthma, hay fever, cancer (especially urinary tract cancer), a particular type of brain cancer called glioblastoma, gonorrhea, dysentery, birth control, bone pains, and "cleansing" the kidneys.
How does it work?
Cat's claw contains chemicals that might stimulate the immune system, kill cancer cells, and fight viruses.
CAT'S CLAW Uses & Effectiveness 
Possibly Effective for:
- Reducing pain from a kind of arthritis called osteoarthritis. Taking a specific freeze-dried cat's claw extract (Uncaria guianensis) by mouth appears to relieve knee pain related to physical activity within one week of treatment, but it does not decrease pain at rest or decrease knee swelling.
- Improving symptoms of a kind of arthritis called rheumatoid arthritis (RA) when used with regular rheumatoid arthritis medications. Taking a specific cat's claw extract (Uncaria tomentosa) that contains chemicals called pentacyclic oxindole alkaloids but is free of other chemicals called tetracyclic oxindole alkaloids appears to improve symptoms of RA somewhat. Taken by mouth in combination with sulfasalazine or hydroxychloroquine for 24 weeks, cat's claw seems to reduce the number of painful and swollen joints.
Insufficient Evidence for:
- Stomach or intestinal ulcers.
- Inflammation of the digestive tract including colitis and diverticulitis.
- Hemorrhoids.
- Parasites.
- Leaky bowel syndrome.
- Shingles.
- Chronic fatigue syndrome (CFS).
- Chicken pox.
- Mouth or genital herpes.
- Human immunodeficiency virus (HIV).
- Wounds.
- Arthritis.
- Asthma.
- Hay fever.
- Cancer.
- Glioblastoma.
- Gonorrhea.
- Birth control.
- Bone pains.
- Other conditions.
CAT'S CLAW Side Effects & Safety
Cat's claw is POSSIBLY SAFE for most people, when taken short-term. It can, however, cause headache, dizziness, and vomiting in some people.
Special Precautions & Warnings:
Pregnancy and breast-feeding: There is some concern that cat’s claw might be UNSAFE during pregnancy. Not enough is known about the safety of cat’s claw during breast-feeding. Avoid use if you are pregnant or breast-feeding.Low blood pressure: There is some evidence that cat’s claw might lower blood pressure. If your blood pressure is already too low, this might be a problem.
Leukemia: Cat's claw might worsen this condition. Don’t use it if you have leukemia.
“Auto-immune diseases” such as multiple sclerosis (MS), lupus (systemic lupus erythematosus, SLE), or other similar conditions: Cat’s claw might cause the immune system to become more active, and this could increase the symptoms of auto-immune diseases. If you have one of these conditions, it’s best to avoid using cat’s claw without consulting with your healthcare provider.
Surgery: There is a concern that cat’s claw might make blood pressure control difficult during surgery. Stop taking cat’s claw at least 2 weeks before a scheduled surgery.
CAT'S CLAW Interactions
Moderate Interaction Be cautious with this combination
- Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates) interacts with CAT'S CLAW
Some medications are changed and broken down by the liver.
Cat's claw might decrease how quickly the liver breaks down some medications. Taking cat's claw along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking cat's claw, talk to your healthcare provider if you are taking any medications that are changed by the liver.
Some medications changed by the liver include lovastatin (Mevacor), ketoconazole (Nizoral), itraconazole (Sporanox), fexofenadine (Allegra), triazolam (Halcion), and many others. - Medications for high blood pressure (Antihypertensive drugs) interacts with CAT'S CLAW
Cat's claw seems to decrease blood pressure. Taking cat's claw along with medications for high blood pressure might cause your blood pressure to go too low.
Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDiuril), furosemide (Lasix), and many others. - Medications that decrease the immune system (Immunosuppressants) interacts with CAT'S CLAW
Cat's claw might increase the immune system. By increasing the immune system cat's claw might decrease the effectiveness of medications that decrease the immune system.
Some medications that decrease the immune system include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), corticosteroids (glucocorticoids), and others.
CAT'S CLAW Dosing
The following doses have been studied in scientific research:
BY MOUTH:
- For osteoarthritis of the knee: 100 mg daily of a specific freeze-dried cat’s claw extract.
- For rheumatoid arthritis: 60 mg daily in three divided doses of a specific cat’s claw extract that contains no chemicals called tetracyclic oxindole alkaloids. These chemicals, while found naturally in some cat’s claw, work against other chemicals in cat’s claw that seem to help rheumatoid arthritis.
