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.
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.