I started using this product in 2010 when it was called MaMa Lotion and the packaging was different. Over the years I continue to go back to this product. I have tried the other M2 products that are 12% and 20% because they had more product, but the original product works the best for me. The product line is sticky and will sting your skin if you do not wait to put it on or have just exfoliated. I love that it causes my skin to peel because that lets me know that it is working. I use this product for hyperpigmentation (I am a dark skin African American). I think it is a 5 star product. When you factor in price, it gets 4 stars because the original amount of product(MaMa lotion was 1.67oz vs 1.0oz for M2) )and cost the same price ( or close to it). Also, I prefer the MaMa lotion packaging because it was easier to get the left over product out of the container and you can clearly tell when you are running low on product.