The present invention relates to processes for degrading plastic products and the uses thereof. The processes of the invention particularly comprise a step of amorphizing a plastic product prior to a step of depolymerization. The processes of the invention are particularly useful for degrading a plastic product comprising polyethylene terephthalate and/or polylactic acid. The invention also relates to a method of producing monomers and/or oligomers from a plastic product comprising at least one polyester, particularly polyethylene terephthalate and/or polylactic acid, comprising submitting the plastic product both to an amorphization step and to a depolymerization step.