from what I see so far (I used it on my husband's back) I used about the size of a half a grain of rice on a bump the sice of a large grape.
the reaction lasted for about two to three weeks, no pain, just itching, then the thing turned black and started closing up a little a a time, and is now skinned over (brand new skin, no scar). There was an indentation the size of a small third of a grape, and is now filled in for the most part (I'll take a look again). There is skin discoloration under, (dark) but don't know if it will go away yet.
I only applied it twice, maybe three times. VERY little.
Don't know if this info helps you - Also once the eruption had ceased, I started putting Hydrogen Peroxide gel on it.