What is cat's claw?

Cat’s claw is a herbal remedy which has antioxidant and anti-inflammatory properties. Only one RCT was conducted to evaluate its role in treating rheumatoid arthritis, which showed some clinical benefits with only minor side-effects when taken along with conventional medications.

  • Family: Herbal medicine of the Rubiaceae family
  • Scientific name: Uncaria tomentosa
  • Other names: Life-giving vine of Peru, una de gato

Cat’s claw is taken from the stem and root of some woody vines native to South and Central America. You can buy capsules over the counter in pharmacies and health food shops.

How does it work?

Laboratory and animal studies have found that cat’s claw can prevent the activation of several inflammatory substances in your body. Studies have also shown that it has antioxidant properties, so it can prevent damage to your body’s cells by interacting with harmful molecules (free radicals) which are produced within your cells.

Is it safe?

We don't have much data on the clinical safety of cat’s claw. No serious side-effects were reported in one trial whose participants had rheumatoid arthritis, but there was one report of serious kidney problems in a woman with lupus.

You should be cautious about taking cat’s claw if you take drug for hypertension because it may increase the effect of these drugs. You should also be cautious about using cat’s claw if you take immunosuppressive drugs. Laboratory studies have also found that cat’s claw can stimulate the production of certain hormones called cytokines. Cytokines are important to your immune system.

One trial used a dose of 60 mg a day of the active component (Uncariae tomentosae), but no studies have been conducted to find an appropriate dosage for musculoskeletal conditions.

Trials for rheumatoid arthritis

In this trial, 40 participants with rheumatoid arthritis took part in the following phases:

  • Phase A – participants were randomised to receive either cat’s claw tablets (60 mg of Uncariae tomentosae) or placebo tablets once a day for 24 weeks
  • Phase B – both treatment groups took cat’s claw for an additional 28 weeks.

All participants were asked to continue their usual treatment of sulfasalazine or hydroxychloroquine during both phases of the trial.

  • 53% of participants given cat’s claw in phase A reported a significant reduction in the number of painful joints compared to only 24% of participants who started on placebo tablets.
  • Participants in both groups didn’t differ with respect to morning stiffness and number of tender or swollen joints during this period.
  • Significant beneficial effects on all clinical aspects were observed in participants who were given cat’s claw for both phases when compared to the placebo group.
  • Minor side-effects (like stomach upsets) were reported in participants who received cat’s claw.