New Zealand Green Lipped Mussel (Perna canaliculus) is used in some nutritional supplements to support joint health, largely due to its content of omega-3 fatty acids, glycosaminoglycans, and other bioactive compounds with purported anti-inflammatory properties. The scientific evidence supporting its use specifically for tendonitis is limited but present, primarily through extrapolation from joint and soft tissue inflammation studies.

A few small randomized controlled trials and animal studies have suggested that Green Lipped Mussel extracts may reduce inflammation and improve symptoms in osteoarthritis and rheumatoid arthritis, conditions characterized by joint and sometimes periarticular (around the joint) soft tissue inflammation. The anti-inflammatory effects are primarily attributed to unique omega-3 fatty acids (such as ETA) and other compounds that may inhibit pro-inflammatory cytokines.

However, direct studies on Green Lipped Mussel for tendonitis specifically are sparse. Most evidence is either anecdotal or derived from broader studies on musculoskeletal inflammation. Systematic reviews of Green Lipped Mussel supplements generally conclude that while there is some benefit for joint pain and function, there is insufficient high-quality evidence for specific conditions like tendonitis. Therefore, its use is somewhat justified by the scientific rationale and limited data, but the overall quality and quantity of evidence for tendonitis is low (rated 2/5).