PEG-MGF is a Pegylated Mechanical Growth Factor. The original version was MGF which had a very short half-life. PEG-MGF is a pegylated version, i.e. synthetically extended so that the duration of action is much longer. Thanks to this, PEG-MGD can be administered subcutaneously (MGF version recommended intramuscularly), because the long period of action will cover the entire body and will show its positive effects on the whole body. PEG-MGF is definitely one of the best peptides for building muscle mass and regenerating muscles after exercise.