Not really, as long as he's not getting it on an empty stomach. If you've found one in pellet form, it should be fine, just make sure he's eaten something beforehand.
I feed most of my horses their supplements first with a little grain then give them their food!
It won't hurt him at all!
I found one that's in pellet form which is why I'm asking. I just don't know if it's bad for him to consume the biotin without eating more food than the little scoop of biotin pellets
It depends on the horse. I have one horse that will eat supplements not mixed in the grain, then I have another that I have to or he won't eat it. If it's just biotin then I would say your good with. It mixing it in because normally it comes in powered form.