We employ high-performance liquid chromatography with evaporative light scattering and mass spectrometric detection (HPLC/ELSD and LC/MS) to monitor the dynamic behavior of L-Pro, L-Hyp, and L-Pro–L-Hyp in 70% aqueous methanol. The individual amino acid solutions show evidence of oscillatory oligomerization. In the binary solution, the behavior is controlled by the dynamics of L-Pro oligomerization. A simple model involving oligomerization, formation of catalytic oligomer aggregates and cross-catalysis provides qualitative insight into the process.