The molecular mechanisms that lead to the generation of adipose tissue (adipogenesis) are of basic and biomedical interest. Cellular models of adipogenesis have proven extremely valuable in defining biomolecules-primarily genes and proteins-that regulate adipogenesis. Here, the analysis of differentiating adipocytes using an untargeted metabolomics approach led to the discovery of the monoalkylglycerol ethers as a natural class of adipocyte differentiation factors.