Green-lipped mussel

Green-lipped mussel is a nutritional supplement taken from a type of mussel native to New Zealand. We don’t really understand how it works, but it contains omega-3 fatty acids, which have anti-inflammatory and joint-protecting properties. Evidence suggests that it might be of some use to people with osteoarthritis when taken along with paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs). It’s not effective in treating rheumatoid arthritis.

• Family: Nutritional supplement
• Scientific name: Perna canaliculus
• Other names: New Zealand mussel, greenshell mussel, Seaton®, GLM, Lyprinol®

Green-lipped mussel is a nutritional supplement taken from perna canaliculus, a bivalve mollusc (mussel) native to New Zealand. You can buy it from high-street retailers.

We don’t yet fully understand how green-lipped mussel works, but we know that extracts contain omega-3 fatty acids, amino acids, minerals and carbohydrates. Laboratory and animal studies have shown that omega-3 fatty acids have anti-inflammatory properties and are important for maintaining joint cell structure and function, and this might be one of the ways green-lipped mussel works in some people.

Green-lipped mussel seems to be relatively well tolerated, although gastrointestinal discomfort (like nausea and flatulence) have occasionally been reported. Interactions with other drugs haven’t been well studied, but you should be cautious about taking it with affect anticoagulants because it may affect these.

No recommended safe doses have been found for use in musculoskeletal conditions.

The number of participants with rheumatoid arthritis included in these trials ranged from 6–47 and the trials lasted from three to six months.

All except one trial found that green-lipped mussel was no better than a placebo in improving the health of participants with rheumatoid arthritis.

Review article‡

The number of participants involved in the trials included in this review ranged from 30–80. The trials lasted between three and six months. Three of these trials (two of which were low quality) compared the potential beneficial effects of green-lipped mussel supplements with placebo capsules. The fourth trial, also of low quality, compared the effectiveness of two forms of the compound (the lipid extract versus powder).

Green-lipped mussel was more effective than a placebo in reducing pain, improving function and improving overall quality of life when taken along with usual painkillers (for example paracetamol) and NSAIDs.

Both forms were effective, with 73% of the lipid group and 87% of the powder group showing significant improvement.

‡ A trial of low quality. Results of this trial were given a lower weighting when we came to our conclusion about the compound.