I am using several of the products and my skin is looking better. I've gotten some really nice compliments recently. I'm hoping as I continue to use the products that they will continue to have a greater impact on my skin. My sister who has been an aesthetician for 30 years has noticed and wanted to know what I was using. So that is a good sign. She doesn't hand out compliments often. I'm not sure how to do the proof of purchase or I would. These products aren't magic. You need to have a good diet, drink lots of water and be consistent in cleaning you face properly and using the products as directed. Georgi Walker