Most doctors do layered peels to make them more aggressive without using higher concentration of the acids. I usually do the Jessners first, followed by the TCA. I usually use 25-35% TCA. Of course your board certified dermatologist of plastic surgeon may have a different method. And the preparation and mode of application can make a world of variations of effects with similar peel strengths. That is one of the main reason to see an experience and certified expert.