These articles give us some idea of the amount of research that has gone into discovering how wheatgrass actually assists "healing" of the extraordinarily broad spectrum of medical conditions and injuries it is capable of. Chlorophyll has been suggested, but there is no evidence to support this theory.
Also, there is no chlorophyll in the wheatgrass extract I have used therapeutically, and highly effectively for treating a very broad spectrum of conditions, since 1995. Numerous biological influences and activities are involved in the healing process, particularly ligands that influence re-activation of dysfunctional cellular receptors, which in turn "re-connects" them to the brain.