Alpha Hydroxy Acids are a group of naturally occurring acids which are derived from certain plants and fruits. The most commonly used form of AHA is Glycolic Acid, which comes from the sugar cane. Which one should I use - What are the differences? The percentage difference is the amount of glycolic in the solution - in other words, the higher the percentage of glycolic, the less inert ingredients in the product. So, the product gets really strong when it reaches 70%... very strong indeed. The buffering agent adjusts the pH of the product: the 30% and 50% are both lightly buffered and have a pH of 2.6 (strong acid).. the 70% is not buffered and has a pH of 0.6 (VERY strong acid, not for use by newbies). All Items Here are all the products in this category: • GLYCOLIC ACID