You have to ask yourself what exactly is unnatural enhancement. How is wearing makeup any different than working out more than your lifestyle requires?
I know plenty of guys who have normal, non-physical jobs and if not for hitting the gym nearly every day, would be average/slim guys. They go to the gym constantly and get huge.
Sure it's something you DO not something you wear, but that's the ONLY difference. You do it to look good, you don't have to be huge to be healthy (actually the opposite can be true, being too big is bad for you); but people do it anyway to look good.
If women want to wear makeup, go for it. As long as it doesn't get pushed on kids as a necessity, it's not a problem in my opinion.