This is partially common sense, of course. "A single-acid peel, like a glycolic peel for example, uses just one type of acid, typically to achieve skin-resurfacing," celeb dermatologist Harold Lancer, MD, tells us. Meanwhile, "A multi-acid peel, like a Jessner's peel, combines various types and strengths of acids to more deeply rejuvenate the skin, [and] remove sun damage or excessive pigmentation." [Ed. note: A Jessner peel is the common name for a certain mix of acids, but more on that later.] So basically, the more acids, the better, right? Not always.
A single-acid peel, like a glycolic peel for example, uses just one type of acid, typically to achieve skin-resurfacing.
Selecting a single-acid peel can allow you to effectively target the area of concern, with less downtime or risk of irritation or allergic reaction. (Translation: The more ingredients on your pizza, the more chances one of them will disrupt your stomach or displease your palate.)
There are many types of refined fruit-enzyme [acids] that are gaining popularity among dermatologists and aestheticians for their gentle effects.
Now that you understand a bit about what single acids do, we'll talk about what can happen when they're combined. By blending different acids, a professional can create cocktails that work on different issues simultaneously. However, some acids, when combined, negatively affect each other — so don't think you can start mixing them at home without knowing what you're doing. "It's really sketchy for anyone that's not quality-controlling the batch to put acids together," Benjamin explains. "When you mix two or more acids together, the pH should be adjusted to a safe [level]."
[Mandelic acid] is a great first-time chemical peel because it's less penetrating and irritating, but still very effective for treating damaged skin.