spunky has crystals again..source of glycosaminoglycans

Poor Spunky, our skitzoid cat of the four siders.  I'm sure you all have had one, runs when the doorbell rings, strange noises scare him, etc.

Anyway I am looking for a source for glycosaminoglycans (Utah Vet Med school) to improve his bladder health.  Anybody have a source for this?  I googled it but found nothing...perhaps a common name for it I don't have.

Help would be appreciated as he comes home from the vet Monday

Pretty sure that the short name for that is GAGs which glucosamine support the reproduction of gags to help repair the mucosa of the bladder. So cosequin is one, and sure there are other supplements as well.