I keep reading that IGF only works well for 4-5 weeks, before your it becomes useless. However, no one really has shown any concrete proof of this. If this was the case, one would assume that GH would be the same. I know of a few 'gurus' who have their atheletes on year round GH & IGF to create new cells. I really don't think the increase in size of pros now a days is due to more AAS, but to new cells created by year round peptide use & then made large by AAS. Any input regarding this?