the brand new batches: pull off the holo and there should be "v-slits" there. the older and mid batches: pull off the holo and there should be dots left behind on the bottle. also the label on the vial should be rounded not square. lot #'s stamped on the box and on the bottle on the mid to newer batches. although i got some old shit here with printed on lot #'s in small red writing. ummmm. let me think some more.