Unfortunately, an AHA is not effective when it is at a ph level of more than 4. AHA works best when it is presented in a formulations between 1 to 4 ph. Ph of 1.8 would be for professional AHA peels and the latter ph level of 4 would be for at home AHA use. If you think you're putting on 50% concentration of Glycolic acid on your skin, you are wrong. If the product was properly formulated it would only be safe to use it by a doctor as a peel, and not a leave on product. For the price of $225 you are definitely getting ripped off. Glycolic acid is a well researched proven AHA that has a ton of information/clinical research behind it - that I will admit. But paying $225 for a readily available glycolic product is just ridiculous.