To add some details... This was unfiltered CJC-1295 DAC from Peptide Sciences. Worked fine for me over course of a year (i.e., got expected rise in IGF-1 level), but only worked for first few months for spouse, who then had a single unusually intense response (more intense than typical CJC flushing), after which IGF-1 dropped to below baseline, and w/o further flushing from CJC injections. In addition, after stopping CJC, IGF-1 levels did not recover over several months, leading us to turn to HGH (w/ filtering). This is more or less like what happened with kids who had an immunogenic reaction to exogenous HGH in studies - some recovered, some didn't, some simply needed higher dosing, etc. Anyway, seems prudent to pay attention to things one can do to minimize immunogenic responses to one's native peptides. (As I recall, some of the studies specified exactly the type of antibodies formed, making it clear that the immune system was directly interfering with one's own peptides.)