thanks for the research my man...Here is one link to a study about IGFBP displacers. The do not however divulge the exact peptides they used, just said that these novel synthetic peptides show promise... Depends also which IGFBP as IGFBP-3 primarily binds to IGF.
SpringerLink - Journal Article
Some info on NBI-31772 non specific IGFBP inhibitor:
Increasing the levels of insulin-like growth facto...[Neuropsychopharmacology. 2007] - PubMed Result
Ligand Inhibitors of IGFBPs:
(WO/1997/039032) LIGAND INHIBITORS OF INSULIN-LIKE GROWTH FACTOR BINDING PROTEINS AND METHODS OF USE THEREFOR
Some more possible info:
The heparin binding domain of insulin-like growth ...[Horm Metab Res. 1999 Feb-Mar] - PubMed Result