I spent about three months or so researching chemical peels. The four most common are Glycolic (AHA), Salicylic (BHA), Lactic, and TCA.
Chemical peels are a form of exfoliation. Most of them wont actually cause your skin to peel (except TCA peels in higher concentrations). Much like manual exfoliation (think scrubs) get the crud off the top layers of you skin, chemical peels accomplish the same, with far less damage or irritation to the skin. Scrubs actually damage your skin by causing tears in the skin that the body must heal. No good. For that reason, chemical peels are a safer and more effective form of exfoliation for the skin. If you are used to using scrubs, it will take some psychological adjustment to get comfortable with tossing your favorite scrub in the trash bin.
Here I will discuss the various forms of chemical peels so you can choose the most appropriate for your skin. The first three, AHA, BHA and Lactic are great for at home use, provided you do not go nuts, you should be fine. They can sting a bit, but nothing to get nervous about. I have found that sometimes, they don't sting at all and others I am hopping about my bathroom unable to last a minute with it on my skin. Regardless, you can neutralize them quickly with regular tap water, so if you are uncomfortable at all, then just rinse it off and wait until next week to proceed. You do not need to buy special neutralizing solution. Water works fine. They will actually self-neutralize after some time anyhow without the use of anything, despite what some uninformed zealots might advise. A follow-up question here and there has proven to me that most people who sell beauty products have no freaking clue what it is they are selling.
My personal favorite chemical peel is BHA, Salicylic acid. I use a great product by Neutrogena, which I mention in my post below on blackheads. This is a 2%, suitable for daily use. I also have a 20% suitable for weekly use that I love (it is not by Neutrogena, but I did get it from Amazon). BHAs work by not only exfoliating the top layer of skin, but they also help to dissolve and loosen the oils in pores that get gunked up and gross. It isn't a miracle worker, but it helps. Also, it has anti-inflammatory properties, so it may be suitable for sensitive skin. I find that, rather than irritate my skin, this 'peel' actually works to calm my skin and keep it happy. If you have never had a chemical peel, you can try it out at a spa first, where you will paid a hundred times the cost of the product they use (the product is so inexpensive it is almost free, if you account for the per-peel cost...maybe one dollar), but will have the psychological comfort of knowing that you are in the hands of someone who has probably done this a time or two.
I have yet to try Lactic Acid, but I just purchased some for the first time. It is supposed to soften the skin and have calming properties as well. BHA remains my gold standard, but I will be giving this a try.
AHA, glycolics, are a great peel and give a greater depth penetration in the skin, but they lack anti-inflammatory properties. In my opinion, inflammation is one of the chief things that we are fighting against in skin care (and in general health), so I choose the more mild BHA. Used on a regular basis, you can get great exfoliation with a BHA and no irritation.
Lets dive on into the last one...TCA. I ventured to try this at home and it was a mistake. This is actually a much more...serious, for lack of a better word, peel that takes off the top layers of skin. It is the only one that actually causes peeling. I tried 25% and, while the complication rate is very low, I was just one of the folks that didn't heal well. I got burns on my skin that left me with persistent redness that I am currently seeking laser beam treatment to correct. It is nothing major and covers up easily with makeup, but would I do the peel again? Heck no. My skin hated it. If I had a do-over, I would have gone to a derms office and had it done. While they charge you out the wazzo (six hundred dollars is highway robbery...jerks), I would not have wondered if I did anything wrong. For what you get from a TCA peels (fresh, bright looking skin that can last several months, possibly lighter freckles) versus the cost (a week downtime and potential complications), I wont be trying it again unless all other options have failed.