I would try cutting with USP grade filtered grapeseed oil. The GSO will mix better than most B12's (most B12 are water based and will look mix but will separate quickly). I always pin quads and had horrible pain about 2-3 days out like attacked by midgets with ballbats pain. Started cutting with GSO in week 3 and went pain free throughout the rest. Same routine though heating pad right after injection and some aspirin. I swap bottle heads then I draw with a 18g 1.5cc of test and 1.5cc air, then to the GSO push about 1cc air in and pull 1.5cc gso out. Then you will have 3cc and pull about 1.5cc more air and shake it up real good. Run hot water over while spinning the syringe for a min or so. Switch to 23g 1" Release excess air and pin away. Make sure on quad pin you are higher than the middle part of thigh to the outside. I've went below the mark a couple times and noticed some knee swelling. Take about 2-3mins to get it all in there but zero pain once you prick the skin. Taking your time and not shaking you will have zero problems.