I was concerned about using these tapes and glues also. Just before I started wearing hair, I had some problems with rashes on my body and would you believe it, just a month before I was scheduled to start wearing for the first time I got red a red rash on the exact spot I was hoping to attach my piece.

But I got some creams, etc. and the rash went away a little. I was still nervous about using a piece, for the first time, but I went ahead. And 10 years later, I haven't had any averse reactions. No rashes, or allergies at all. The only issue I've ever had with glues is that is you have a 3 week long attachment it will get a bit goey