So I tried an at-home TCA peel. I purchased two strengths - 12.5% and 15% - with the intention of using just the 12.5% first. I use Retin-A, so my skin was prepped, and I stopped using it a few days before the peel.
I applied the 12.5% over my whole face and it didn't frost at all. After five minutes, I neutralized the peel. Then I applied 15% just over two old acne scars on my left cheek. I'm in my thirties, and these scars are from my teens. Shallow boxcar scars.
The scars frosted under the 15%, and I waited a few minutes before I neutralized it.
It's been a week and the 12.5% didn't seem to have a great effect, but I'm still giving it a little time. All I notice is a more even appearance, but that could just be my perception. That said, the area that frosted - over the scars - did go through the peeling process.
Day One: it was a little tight.
Day Two: it took on the appearance of a dried smudge of Elmer's Glue, like something was on my cheek. It was slightly discolored - sort of a faded light brown - but nothing dramatic.
Day Three: it started peeling. By the end of Day Three, it was gone.
To give you context, I was moisturizing constantly with Argan oil, so when it reached the peeling stage, it was quite soft, with dry, loose edges that gradually frayed. By the end of Day Three, as I was massaging the spot with oil, it rolled off.
And I'll tell you this: those two scars are so shallow now that they're not even noticeable. I wish I'd taken photos.
Honestly, I didn't think it would work. I'd pretty much assumed that any scar that old was there for good. And I figured that if it did work, it would probably take many peels and of a much stronger strength. In no way did I expect a 15% to do that trick.
Before, it was most noticeable in dramatic lighting - my left cheek looked pitted. So I tested it by shining hard, oblique light on my cheek and sure enough, it's hardly noticeable now.
So my thoughts: sure, test it on your skin first to see how it reacts. I thought mine would be more sensitive, but the 12.5% had no negative effects whatsoever (and possibly no positive effects). Regarding the frosted area and the 15%: if my whole face had been like that one patch, I definitely would have stayed inside, and I imagine it would make life difficult. Since it was just one spot, I could hide it with my hair, and it didn't make me look too much like a freak. But also, it didn't take that long - I might try a full face at 15% in the future.
Last thing: while it was peeling, when the surface was like a patch of dried glue, it definitely wrinkled. There was a moment when I worried that it would train my skin to be wrinkled in that spot, where it had previously been smooth. And it exaggerated the scar. So sure, for a day, I was a little nervous. But once the real skin was revealed, there was certain no wrinkle and a nearly imperceptible scar. So I wouldn't worry about it if it happens to you. Just let the skin heal and shed.