~/.zprofile are only read if the shell is a login shell. Did you set zsh as your default shell using
cshsh or just in the preferences of the terminal emulator? If the former, logging out and back in should do the trick (although, the file will be only read when you actually perform the login, not when you start a new shell), or you have to tell your terminal emulator to execute the shell as a login shell. If you are using
gnome-terminal, go to
Edit->Profile Preferences, select the
Title and command tab and check the
Run command as a login shell box.