Cat's Claw May Enhance Immune Function

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By Agata P. | Updated: Nov 17, 2023

Cat's Claw May Enhance Immune Function
General Information
  • 01 Jan 2001
  • Sweden
  • University of Lund
  • Lamm, S. et al
  • Clinical trial
  • 23 men
  • 2 months

Pneumococcal infections can be caused by a wide variety of strains from Streptococcus pneumoniae bacteria, and may lead to serious health problems. Although vaccines can help prevent them, they are only about 60-70% effective, putting vulnerable populations at risk.1

Cat's claw has been used by indigenous people of South America for medicinal purposes for centuries. One of its traditional uses include strengthening the body's immune response, although the exact mechanism behind these actions is not fully understood.

Swedish researchers conducted this trial to assess whether cat's claw can improve immune response in people vaccinated with the pneumococcal vaccine, thus boosting its effectiveness.

The Study

This clinical trial included 23 men, between the ages of 40 and 60. Patients were never vaccinated with pneumococcal vaccine prior to entering the study.

They were assigned to two groups: the first group was receiving a daily dose of 750 mg of cat's claw extract, while the second group was not consuming any supplements. The intervention lasted for two months.

Participants underwent medical exams and blood work to assess the levels of pneumococcal antibodies before and after being vaccinated with the pneumococcal vaccine. The results of this trial were published in the Phytomedicine journal.

The Results

Researchers observed that the neutrophil-to-lymphocyte ratio was statistically changed in men taking cat's claw extract.

For reference, neutrophils and lymphocytes are types of white blood cells that play key roles for immunity. An increased percentage of lymphocytes is linked to enhancing immune response.

Also, men in the cat's claw group had no loss of pneumococcal immunity at the 5-month check-up, whereas those in the control group had a significant decline.

No significant side effects were reported throughout the trial.

What Does this Mean?

This trial has demonstrated that cat's claw has immune-modulating properties. It is believed to improve immune response by stimulating a greater proportion of lymphocytes.

Thanks to these benefits, cat's claw extract could be used to boost the effectiveness of the pneumococcal vaccine and reduce complications associated with pneumococcal infections.

Further studies are needed to better explore the benefits of cat's claw for immunity as well as its potential pharmacological applications.

Other herbs with immunity-boosting actions include camu camu, turmeric, ginger, and blueberries.


  • Phytomedicine, Persistent response to pneumococcal vaccine in individuals supplemented with a novel water soluble extract of Uncaria tomentosa, C-Med-100®, 2001


CDC. (2022). About Pneumococcal Vaccines. Retrieved March 23, 2022 from