At first, I bought half a dozen of these.  Nothing artificial...  But after some time they became uncomfortable to wear through out the day, the front sides ride up to much and ended up chafing between my legs on either side of of my stuff.  I don't wear them any more.  They caused skin irritation when I wore them for extended periods of time.

UPDATE!
January 6, 2014
I bought about six pair of these underwear at one time and I never wear them.  As a matter-of-fact I was cleaning out my underwear drawer and I found two pair of these still in their original packaging.