Unfortunately, I also got it in one of the Lyko boxes. And unfortunately, because now I am addicted. ;) I thought it was incredible and you can REALLY see a difference, especially me being older. I am 38.
My skin has never been so even. But as I said, it is an active product, so it may require building up as it can damage the skin barrier.
So tips here for sensitive or reactive skin:
• 1 time a week to start with, in the evening.
• Always on completely dry skin (after washing, wait 15–20 min).
• Follow up with a mild, moisturizing cream without active ingredients. I have sometimes also used it before. Like cicaplast or similar.
• Never in combination with other active ingredients (retinol, vitamin C, BHA, etc.).
• Mandatory sun protection every day if you use it – the skin becomes sun-sensitive.
Glycolic acid peels deeply and can give a really nice effect – but overuse can damage the skin barrier, and then the skin becomes red, thin, reactive, flaky, or even burning. So better rarely than too often. But I REALLY recommend!