Whats the best hair serum for damaged hair?

I love Enjoy oil or Paul Mitchell Super Skinny Serum. Smells awesome and works wonders especially with frizz. A good leave in conditioner would also work great the best is its a 10 leave in conditioner. Little goes a very long way. Also you want to make sure you are doing deep conditioners once to twice a week. I love joicos instant hydrator!!! You will notice a difference right away!! You would just shampoo normally and use deep conditioner instead of your daily conditioner. Head and Shoulder will dry out your hair like crazy. You need to use professional products that is your huge problem. The drugstore brand adds wax to your hair that is what the shine is. Hope this helps you some!!