Sodium oligomannate (®; GV-971) is a marine algae-derived oral oligosaccharide being developed by Shanghai Green Valley Pharmaceuticals for the treatment of Alzheimer's disease (AD). Sodium oligomannate received its first approval in November 2019 in China for the treatment of mild to moderate AD to improve cognitive function. This article summarizes the milestones in the development of sodium oligomannate leading to this first approval for AD.