From my understanding, MGF and PEG-MGF are both growth/repair factor (IGF-1Ec [has more localized effects] a diff factor than IGF-LR3 [systematic effect]). Both can be used to bring up weak body parts and possible site enhancement (in theory it is possible since IGF in general promotes hypertrophy and MGF is produced locally in trained muscles [let's say after you train ur arms, ur muscles there produce MGF along with other compounds]). MGF has a very short half life and is used immediately after your workout, PEG twice a week (since its has longer half life). You may need to do more research on this. I'm not sure about your "bulking" question, however I don't think that they would give that kind of "gains". Check out PM sponsors for legit products.
