Cat’s Claw: Benefits, Side Effects, and Dosage

Written by Mary Jane Brown, PhD, RD (UK) (via Healthline)

Cat’s claw is a popular herbal supplement derived from a tropical vine.

It allegedly helps fight a range of ailments, including infections, cancer, arthritis, and Alzheimer’s disease (1Trusted Source).

However, only some of these benefits are supported by science.

This article tells you everything you need to know about cat’s claw, including its benefits, side effects, and dosage.

What Is Cat’s Claw?

Cat’s claw (Uncaria tomentosa) is a tropical vine which can grow up to 98 feet (30 meters) tall. Its name comes from its hooked thorns, which resemble the claws of a cat.

It is found mainly in the Amazon rainforest and in other tropical areas of South and Central America.

The two most common varieties are Uncaria tomentosa and Uncaria guianensis. The former is the type often used in supplements in the United States (2Trusted Source).

The bark and root have been used for centuries in South America as a traditional medicine for many conditions, such as inflammation, cancer, and infections.

Cat’s claw supplements can be taken as a liquid extract, capsule, powder, or tea.

SUMMARY

Cat’s claw is a tropical vine used for centuries as a traditional medicine. Today, it’s commonly consumed as a supplement due to its alleged health benefits.

Potential Health Benefits 

Cat’s claw has soared in popularity as a herbal supplement due to its alleged health benefits — though only the claims below are backed up by sufficient research.

May Boost Your Immune System

Cat’s claw may support your immune system, possibly helping fight infections more effectively.

A small study in 27 men found that consuming 700 mg of cat’s claw extract for 2 months increased their number of white blood cells, which are involved in combating infections (3Trusted Source).

Another small study in four men given cat’s claw extract for six weeks noted the same results (4Trusted Source).

Cat’s claw seems to work both by boosting your immune response and calming an overactive immune system (3Trusted Source5Trusted Source). 

Its anti-inflammatory properties could be responsible for its immune benefits (6Trusted Source).

Despite these promising results, more research is needed.

May Relieve Symptoms of Osteoarthritis

Osteoarthritis is the most common joint condition in the United States, causing painful and stiff joints (7Trusted Source).

In one study in 45 people with osteoarthritis in the knee, taking 100 mg of cat’s claw extract for 4 weeks resulted in reduced pain during physical activity. No side effects were reported.

However, there was no change in either pain at rest or knee swelling (8Trusted Source).

In an eight-week study, a supplement of cat’s claw and maca root — a Peruvian medicinal plant — reduced pain and stiffness in people with osteoarthritis. In addition, participants needed pain medication less frequently (9Trusted Source).

Another trial tested a daily mineral supplement alongside 100 mg of cat’s claw extract in people with osteoporosis. After 1–2 weeks, joint pain and function improved compared to those not taking the supplements (10Trusted Source).

However, after eight weeks, the benefits were not sustained.

It should also be noted that it can be difficult to determine the specific actions of cat’s claw in studies that test multiple supplements at once.

Scientists believe that cat’s claw may ease osteoarthritis symptoms due to its anti-inflammatory properties (6Trusted Source8Trusted Source).

Keep in mind that more research is needed on cat’s claw and osteoarthritis (11Trusted Source).

May Relieve Symptoms of Rheumatoid Arthritis

Rheumatoid arthritis is a long-term autoimmune condition that causes warm, swollen, painful joints. It is increasing in prevalence in the United States, where it affects more than 1.28 million adults (12Trusted Source).

Some studies suggest that cat’s claw can help relieve its symptoms.

For example, a study in 40 people with rheumatoid arthritis determined that 60 mg of cat’s claw extract per day alongside regular medication resulted in a 29% reduction in the number of painful joints compared to a control group (13Trusted Source).

As with osteoarthritis, cat’s claw is thought to reduce inflammation in your body, easing rheumatoid arthritis symptoms as a result (6Trusted Source).

Although these results are promising, the evidence is weak. Larger, better-quality studies are needed to confirm these benefits.

SUMMARY

Research suggests that cat’s claw extract may aid your immune system and reduce symptoms of osteoarthritis and rheumatoid arthritis. However, more studies are needed.

Unfounded Health Claims 

Cat’s claw contains several powerful compounds — such as phenolic acids, alkaloids, and flavonoids — that may promote health (14Trusted Source15Trusted Source).

However, there is currently not enough research to support many of its supposed benefits, including for the following conditions:

  • cancer
  • viral infections
  • anxiety
  • allergies
  • high blood pressure
  • gout
  • stomach and bowel disorders
  • asthma
  • ovarian cysts
  • AIDS

Due to the lack of research, it’s unclear whether cat’s claw is an effective or safe treatment option for any of these ailments.

SUMMARY

Despite many marketing claims, there is insufficient evidence to support using cat’s claw for conditions like cancer, allergies, and AIDS.

Safety and Side Effects

While side effects of cat’s claw are rarely reported, available information to determine its overall safety is currently insufficient.

The high levels of tannins in cat’s claw may cause some side effects — including nausea, stomach upset, and diarrhea — if consumed in large amounts (1Trusted Source).

Case reports and test-tube studies support other possible side effects, including low blood pressure, increased risk of bleeding, nerve damage, anti-estrogen effects, and adverse effects on kidney function (16Trusted Source17Trusted Source18Trusted Source).

That said, these symptoms are rare.

It is generally advised that the following groups of people should avoid or limit cat’s claw:

  • Pregnant or breastfeeding women. Cat’s claw is not considered safe to take during pregnancy or breastfeeding due to a lack of safety information.
  • People with certain medical conditions. Those with bleeding disorders, autoimmune disease, kidney disease, leukemia, problems with blood pressure, or who are awaiting surgery should avoid cat’s claw (1Trusted Source19Trusted Source20Trusted Source).
  • People taking certain medications. As cat’s claw may interfere with some drugs, such as those for blood pressure, cholesterol, cancer, and blood clotting, you should speak to your doctor before taking it (19Trusted Source).

The lack of safety evidence means that you should always use cat’s claw with caution.

SUMMARY

There is insufficient research into the risks of cat’s claw, although side effects are rare. Certain populations, such as pregnant women or those with particular medical conditions, should avoid cat’s claw.

Dosage Information

If you decide to take cat’s claw, note that dosage guidelines have not been established.

However, WHO says that an average daily dose is 20–350 mg of dried stem bark for extracts or 300–500 mg for capsules, taken in 2–3 separate doses throughout the day (21).

Studies have used daily doses of 60 and 100 mg of cat’s claw extract for treating rheumatoid arthritis and osteoarthritis of the knee, respectively (8Trusted Source13Trusted Source).

One potential risk is that many herbal supplements — including cat’s claw — are not tightly regulated by the FDA. Therefore, it’s best to purchase cat’s claw from a reputable supplier to reduce the risk of contamination.

Look out for brands that have been independently tested by companies such as ConsumerLab.com, USP, or NSF International.

SUMMARY

Available information to develop dosage guidelines for cat’s claw is insufficient. However, average daily doses range from 20–350 mg of dried bark extract or 300–500 mg in capsule form.

The Bottom Line

Cat’s claw is a popular herbal supplement derived from a tropical vine. 

While research to support many of its supposed health benefits is limited, some evidence suggests that cat’s claw may help boost your immune system and ease symptoms of osteoarthritis and rheumatoid arthritis.

Because safety and dosage guidelines have not been established, it may be best to consult with your doctor before taking cat’s claw.

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