Skin Care Tip: Skincare products don't 'age' well

This is a tremendous website. I learned so much and felt it wasn't 'paid for by our sponsors.' I finally realize why the Retin A, retinol and some other products I have been using have decreased in effectiveness over time. They are losing potency with age, and due to their expense I have been using them sparingly and even keeping some beyond their date of effectiveness. I recommend throwing out products that are more than 6 months old and just bite the bullet with expense and keep a fresh supply on hand. I have noticed the difference by keeping a date of purchase mark on all my products.