With a prevalence of over 20%, osteoarthritis, or degenerative joint disease, is the most common form of joint disease in dogs. Green-lipped mussel (GLM) powder is widely used for prevention and treatment of osteoarthritis and may reduce, or even eliminate, the need for conventional medical therapy—NSAID’s in particular. GLM must be processed gently, which necessitates careful excipient selection. This study evaluates the excipient selection for formulations of palatable tablets with a 500mg GLM content and focuses specifically on which of the selected excipients yields the optimal compactibility in a simple direct compression process.