The worst I've felt has been some vasoconstriction and nausea, and only at huge >50mg doses so I would veer to the skeptical side on this. I think this is one of the safer RCs out there, really.
Works fine, very similar subjectively to sublingual use, though maybe a bit stronger, with less of a tail. I think sublingual/insufflated use is best with this compound, for me at least - I don't really enjoy the "tail" of the experience much.