could be a php error occurring causing the redirect to fail.
add the following code at line to turn on error reporting for troubleshooting purposes:
<?php
error_reporting(E_ALL);
ini_set('display_errors','on');
?>
let me know when that code has been added and i'll take a look.
also, if you could send a copy of the /help4health_products.php page in a zip archive so i can examine the code, that would be helpful.