i don't know how it works but this stuff is amazing, especially for bikini line hair removal which always causes ingrowing hairs, you use it 3days prior to shaving then everyday after and it really works and also slows down hair regrowth. I will definately be purchasing it again, but not for a while because you feel like you have used loads but the bottle's still full! A word of caution though, it says on the bottle "proven to cause birth defects in California" so not for the pregnant or wanting to get pregnant.