I have used this product for a long time. I have a conditon that always requires me to stay rptected and I find along with hydra cool Serum and Proheal Serum I strike a great babalce , My aesthetic nurse first recommednded Sheild . However, I recently tried to purchase all three on line using PayPal but the wholeorder got messed up .you finally refunded me the mlney but I eally wanted my product. One other comment about the other 2 bottles is that athe thread can often break and the product i s compromised when travelling. you really need t address this. Ove lost lots of product by broken threads in the top of the stopper bottle of Pro Heal Serum.