New Zealand Green Lipped Mussel (Perna canaliculus) extract is used as a dietary supplement purported to support joint health, including in conditions like Rheumatoid Arthritis (RA). The rationale for its use is based on its content of omega-3 polyunsaturated fatty acids, glycosaminoglycans, and other bioactive compounds believed to possess anti-inflammatory properties. Several small-scale randomized controlled trials and open-label studies have investigated its efficacy in RA. Some studies have reported modest improvements in joint pain, stiffness, and functional ability, while others have found no significant benefit compared to placebo. A 2008 Cochrane review concluded that while there is some evidence of a mild positive effect on symptoms, the overall quality of evidence is low, with methodological limitations and inconsistent results. Larger, well-designed clinical trials are lacking. Most clinical guidelines do not recommend Green Lipped Mussel extract as a standard treatment for RA due to insufficient and inconsistent evidence. However, its safety profile appears favorable, with few reported side effects. In summary, the use of New Zealand Green Lipped Mussel for RA is supported by preliminary scientific studies suggesting possible benefit, but the strength of the evidence is weak and further rigorous research is needed to draw firm conclusions regarding its efficacy.