Used glycolic 8% first time! My upper limit?

Last night I used this 8% glycolic resurfacing solution for the first time. This is the first time I’ve ever used glycolic acid on my skin, except for one, one-time use years ago when a dermatologist prescribed 70%(!) glycolic for a tiny blemish. (That was weird. Luckily my skin survived.) As a woman of colour, with kind of sensitive, normal-dry, older skin, I had had second thoughts about even trying the glycolic, and I was extremely cautious. But for the past 5-6 weeks or so, I’ve been carefully using other, less powerful actives, with no problem. So, I washed my face and started with The Ordinary’s Niacinamide 10% with zinc. I let that dry. Then I started layering the glycolic. I just used my hands. For about the first 15 minutes, it did start to tingle and itch a bit. On some spots it even started to feel like tiny needle pricks. But after those first 15 minutes or so, the sensations lessened, then stopped. I let the glycolic dry completely before I put on a mixture of squalane (oil) and Naturium’s plant ceramide moisturiser.

I feel like the borderline intensity of the 8% glycolic may have been the “upper limit” of MY skin’s tolerance for this acid, at least for now. My skin feels fine and looks normal; no tenderness or other signs of irritation. If I had realised before (that 8% glycolic already is pretty strong), probably I would have started with a gentler glycolic formula, maybe 5% or 7%.

Tonight I’m returning to my prescription azelaic acid, maybe layering it with niacinamide 10%. Did I hear that niacinamide is NOT compatible with vitamin C serum?? I use BeautyStat’s Universal C Skin Refiner (20% L-ascorbic acid). I’m about to reapply my sunscreen for the 3rd time today, probably with two more applications between now and 7pm tonight.