I have tried this serum before they changed the formula adding ISO. I like this new serum as much, it did take me a while to see that the new formula is actually as good if not better. Paul G is one of my favorite people! This man is the reason why I shop here. Never been treated so well and this man is just the best! If you ever have a problem please let him know, I trust him with my skin like no one else. The shop gets my vote for best spa relations! You have to look no further than Paul Labrecque to purchase your BR products.