not gnc products specifically, but just supplements that can be found there. I'm trying to gain muscle for my bodybuilding competition coming up in May, I was using CytoGainer for 3 months and it was amazing. I recently switched on to Amplified Mass XXX and it tastes horrible. However, i still don't know how effective it is. So far, i think i might go back to CytoGainer but if anyone has different suggestions, please let me know