I have used a mixture of prescription tretinoin and Paula's Choice's 1% retinol booster for ... 25? years. I dropped the prescription stuff about 10 years ago just because I forgot to renew it one day and then never bothered. I have never noticed a difference in my skin. Anyway, I am now thinking of switching to Beauty Pie's 4% retinol booster, but am having trouble comparing/contrasting the ingredients list. Is there anyone out there who can dissect them and report back on the pros/cons of switching? Thanks.