Abstract Genipin is known to polymerize under basic conditions, and the obtained genipin oligomers might have an impact on the chemical and physical properties of the crosslinked materials. In this study, we intend to mimic the experimental condition in which genipin is used as a chemical crosslinker. We focus on the degradation of genipin at neutral and slightly acidic conditions using NMR. We report genipin polymerization at neutral and acidic conditions. Unlike dialdehyde crosslinkers, genipin requires heating to promote its crosslinking activity. We found that elevated temperatures enhance the degradation of genipin and promote its polymerization.