There's nothing gentle about this product. Of course it works very well, but you'll feel where you put it.
I have acne prone skin, so can break out in patches on any part of my face. Applying this to a larger area is very tightening and drying. Of course this can be exactly what a big pimple needs, so stick to spot treatment, don't use on non-blemished areas of your face. It causes dryness and slight redness.
Another friend who's used this couldn't tolerate it at all. Her skin went blotchy and red and she said it burned an hour after applying it.
This does all it says it will, but don't expect a gentle ride to clear skin. Note: I don't have even vaguely sensitive skin. Oily and resilient all the way.
I found the zit zapper to be quite good, applying it 3 times daily to specific areas I found that it sped up the process of the pimple forming, meaning that I could pop it and it would be done with without any scarring. If you have very sensitive skin I can imagine that it could be quite painful as it does have quite a strong 'zap' to it once first applied.