There are natural thyroid meds made from Bovine Thyroid.
Generally speaking, you seem to need more of the Bovine to squash the Hypo symptoms with the Bovine vs the Porcine, but in the end they both get the job done.
I know a Jewish guy who gets around the whole not eating pork thing by letting the Porcine Thyroid dissolve in his mouth and absorbing it sublingually. Just a technicality, but works for him.