The search for ways to enhance the stability of PETN against sublimation and coarsening, as well as controlling its thermodynamic properties, is of great interest. In this article, the possibility to use biological molecules to enhance the stability of the important explosive PETN was investigated using thermogravemitric analysis (TGA). Doping PETN with free and metallated porphyrins result in the formation of more stable crystals. Hydrogen bonding between free porphyrins and metal coordination of metallated porphyrins is most likely to play an important role in the crystallization process of PETN. The results indicate the ability of porphyrins molecules to affect/control the thermodynamic properties of PETN inducing a desired higher stability against sublimation. This study opens the door to investigate the use of polymers to enhance the stability of energetic materials.