My humble non-scientific opinion is that you should not re-use them, so that the product is not contaminated. I would suggest cutting them in half and using half a pad on each instance. You can clean a pair of scissors with alcohol for that. I have done this for eye pads that were too big.

i use it after washing my face as a toner.

I think this in combination with Retin-A would be a bad idea. The acid is pretty strong and it might react with the Retin-A (which is PRETTY strong best I remember.)

I suspect that you might not even need the Retin-A if you used these. My acne has really cleared up since using Max Complexion Correction pads.

yes! i find that the skin will become very dry due to the ingredients that are in the solution. The moistrizer will keep the skin balanced and look much smoother and refined.

After I take a shower at night, I use one pad on my chest, upper back and face. One pad has enough solution that I don't need more than that on those three areas. In the morning after I wash my face and before I dress for work I do the same thing again, one pad on those three areas. You don't have to wash the area before using the pad because the pad is made to cleanse your skin as well as treat it.

After use your face might seem a little tighter but well moisturized unless your skin is very very dry -internally dry- then you might want to use an oil based moisturizer or heavy cream moisturizer depending on your PH after use of these pads.
In the winter it is a good idea to always apply some sort of moisturizer regardless of the cleansing product you use, but I would say no this product should not increase the dryness of your skin but it is not any substitute for a daily moisturizers

As far as applying this product to other areas of skin, I would imagine there are great benefits but I would test the area first and then careful watch its progression. If you are already using this product on your face then you are probably not allegeric so there should not be any problems

For me it burns a bit, but not to the point of being truly painful and the burning goes away within maybe 10 minutes.

I would use it more than twice a week but if your scared don't use it anymore. i believe that it will still work if you use it twice a week. after the first day for me it work fantastic and i bet the effects will still be great!

That ia a judgement call for you. I mostly use it before I go to bed after I go through my skin care routine. At certain "times of the month" I have used it more often like Midday to wipe away the oils. You have to see what works best for your skin type and how it affects you directly.

I have been using the clarsonic and the Peter Thomas Roth pads together for awhile now and have never had a problem. I have the sensitive brush head on my clarsonic. After I use it, I use the smooth side of the PTR pad first & then the textured side to really clean & exfoliate it.