What is it?

Pine bark is a herbal extract which is available in the UK under the trade name Pycnogenol®. It’s rich in several bioflavonoids that have both anti-inflammatory and antioxidant effects. The little evidence available suggests that pine bark extract may result in an improvement in the symptoms of osteoarthritis.

  • Family: Herbal extract and nutritional supplement
  • Scientific name: Pinus pinaster ssp. Atlantica
  • Other names: French pinus maritime bark, Pycnogenol®, pinus maritima, pygenol, PYC

Pinus pinaster is a type of pine tree native to France. The water extract of its bark is used treat several diseases, including some types of arthritis. You can buy it from high-street shops.

How does it work?

Pine bark extract is rich in plant pigments called bioflavonoids. Several laboratory studies have found that some of these bioflavonoids have anti-inflammatory and antioxidant properties. Antioxidants are substances that can override harmful molecules (free radicals) which are produced within your cells and which may cause tissue damage or disease. Other studies have found that it can reduce the production of specific enzymes that break down cartilage.

Is it safe?

No major side-effects have been reported in previous trials, although minor side-effects include stomach upsets and headaches. In theory, pine bark may lower blood pressure and blood sugar level, and these effects have also been reported in some RCTs. For that reason, you should be careful taking pine bark if you have hypertension or diabetes.

We don’t yet know what the best dose to use is, but studies have used two 50 mg Pycnogenol® capsules per day.

Pine bark trials for osteoarthritis

Pine bark trials for osteoarthritis Trial 1

In the first trial, 156 participants with osteoarthritis pain that wasn’t well controlled with non-steroidal anti-inflammatory drugs (NSAIDs) were randomly selected to receive either 100 mg daily of pine bark or placebo capsules. All participants were free to use NSAIDs throughout the three-month trial.

  • There was a 56% reduction in pain in the pine bark group compared to only a 10% reduction in the placebo group.
  • The pine bark group showed significant improvements in foot and ankle swelling, joint stiffness and physical function. Pine bark was significantly more effective than the placebo in all these aspects.
  • The use of NSAIDs dropped by 58% in participants taking pine bark compared to only one per cent in the placebo group.
  • The pine bark group had a significant reduction in gastrointestinal symptoms compared to almost no reduction in the placebo group. This might be related to their lower NSAID use.

Trial 2

In the second trial, 100 people with mild osteoarthritis of the knee were randomly allocated to receive either 150 mg Pycnogenol® or a placebo for three months.

  • Participants receiving Pycnogenol® reported an improvement in function and lower levels of pain in comparison to the group taking the placebo, who showed no improvement.