I just wanted to address the most recent myth surrounding propylene glycol as a miracle ingredient being used by the "Mcmethode " folks. Propylene glycol is used for two reasons in skin and hair products one is as a thickening agent to make the shampoo thick or gel like because of the misconception that thicker means stronger. The other reason is it helps the product absorb into the skin or hair better. Now it is useful in pulling the useful properties of a product into the hair it in itself doesn't remove anything.