Question

What happens to hormones after they complete their function?

Answer 1

they are either degrade or destroyed

Explanation:

Hormones when they finish their function are degraded or destroyed.

An interesting fact i came across is that some of the hormones when they degrade give rise to a new peptide or chemical which then again act as a ligand for the receptor.

If you need more info, it is not upto date but will do for basic understanding
http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/basics/chem.html