A 400-participant randomized controlled trial will compare three distinct omega-3 formulations—high EPA, high DHA, and high sn2-DHA—against corn oil placebo over six months in older adults with compromised grip strength. Each group receives 2.5g daily doses, with handgrip strength as the primary endpoint alongside muscle mass and inflammatory markers. This represents the most comprehensive head-to-head comparison of omega-3 variants for sarcopenia prevention to date. The inclusion of sn2-DHA, where the fatty acid occupies the middle position of the triglyceride backbone, addresses growing evidence that molecular positioning affects bioavailability and tissue uptake. Current sarcopenia interventions rely heavily on resistance training and protein supplementation, with mixed results from omega-3 studies often attributed to dosing inconsistencies and formulation differences. This trial's robust design—adequate sample size, standardized dosing, and direct comparisons—could definitively establish whether specific omega-3 configurations offer superior muscle-preserving benefits. The gut microbiome analysis adds contemporary relevance, given emerging links between intestinal health and muscle metabolism. However, the six-month duration may be insufficient to detect meaningful muscle mass changes, and the population's baseline omega-3 status remains unspecified.