I use
@StadaLabs which also is 1500mg. Originally I did 3ml (I may or may not have just not felt like drawing more bac again and figuring I was tough enough to handle it) and shot my forearm, damn near couldn’t type for work that morning
Next shot (and since) have reconstituted at 6ml per vial and since it’s been painless. Obviously you still feel it while pinning just a touch since it’s glutathione, but 0 lingering pain at 250mg/ml.