What makes you blush?

  Lip and cheek stains have long been a staple in many cosmetic bags.  My personal favourite is Benefit's cult classic, Benetint.  It is a translucent, red liquid that can provide a subtle, pink glow to cheeks, or if layered, a deep crimson to lips.  But what exactly causes a stain to do just that - stain?
  Benetint has a very short list of ingredients such as water and glycerin, pretty standard.  But the ingredient that is responsible for generating that rosy glow is quite interesting.  It's called carmine, and is derived from an interesting source - the female insect Doccus cacti, which live on the pear cactus plant and are native to Mexico.  Prior to laying eggs, these insects turn a bright red colour, and this is the time when they are collected and harvested.  The red shells are dried and mixed with a solvent to create a liquid, and the other insect parts discarded (obviously, ew!) 
  I found this quite interesting - as carmine has been used as a dye or stain since the Aztecs.  Other uses of carmine are in paint and food colouring.  The actual compound is a sugar, and comprised of simple atoms such as carbon, oxygen, and hydrogen, which classifies it as organic.  The compound is extracted as carminic acid, the formula shown below.



Carminic acid

Carmine information