Restrict Admin Area To Only Admin Users

Restrict Admin Area To Only Admin Users

function restrict_admin()
{
    if ( ! current_user_can( 'manage_options' ) ) {
                wp_redirect( site_url() );
                exit;
    }
}
add_action( 'admin_init', 'restrict_admin', 1 );


Or
Only Allow Admins Into The Admin Area:

===================================================
function admin_login_redirect( $redirect_to, $request, $user )
{
    global $user;
    if( isset( $user->roles ) && is_array( $user->roles ) ) {
        if( in_array( "administrator", $user->roles ) ) {
            return $redirect_to;
        } else {
            return home_url();
        }
    }
    else
    {
        return $redirect_to;
    }
}
add_filter("login_redirect", "admin_login_redirect", 10, 3);