The percentage of glycolic acid is 29.5% which at first may strike you like a large amount BUT remember where you are placing this product: it is not too harsh on the rough soles and heels of your feet or your elbows, if you need too. I have lightly rubbed the residual cream after rubbing it in on my feet and heels on into the rough patches, if any on my knees with no burning or adverse effects at all.
I have fair skin and burn easily although I tolerate 0.1% retinoid products on my face and I have never had any problem with this Glytone product at all, as I stated when my jar is running low I immediately order another. I love the lip balm they have too, that is best I have come across so far and I won't be without it either anymore. No more chapped lips in the morning! FYI: no glycolic acid in the lip balm.