Why? I love using this product as it visibly diminishes deep wrinkles leaving my skin smooth and even textured. In the past, every retinol cream I tried would leave my skin extremely irritated and red. I gave up on using retinol thinking it just wasn’t for me, until this. With the time-released delivery system along with the soothing green tea polyphenols, I can use this retinol cream nightly without any irritation. What else is great about this product, and the rest of our ZG line, is that it is not tested on animals and is vegan friendly.