The animal models suggest there are no adverse side effects. For examply no weight loss or other obvious disorders. Based on the theory that the Hh pathway is normal used for repair and maintenance it is not surprising that turning of a pathway that is already turned off except in cancer cells have little side effects. But what about cells that are normally dividing rapidly? Side effects for the antagonist might include spermatogenesis146, T-cell regulation147,148, erythroid differentiation149,150, hair growth151, fat absorption152, and possibly intestinal lining. Also because Hh pathway is essential for developmental processes, soon to be mothers should not be subjected to Hh antagonist.

From the drew paper