My understanding is that the law in the united states mandates that the label accurately reflects the contents and if the lable says 1000mcg of b-12 that is what is in it. Furthermore if one were to take the advice to go with human grade @$2/1000mcg of b-12, to get the equivalent of that $5.00 100ml bottle of certified vet grade would cost $200! In the absence of any negative reports on vet grade and with the anecdotal experience of multitudes of users of vet grade for a variety of uses(me included), I would continue to use vet grade hands down. I wonder how many bbrs actually use human grade, everyone I know, uses vet b-12 for the reasons above.