[Routine Help] How long does it take for a product to show any (good) effect on your face?

Beauty Tips For Body Care
Recently added red stridex in a box to my routine (few days ago, put one on every night during pm routine). I haven't really seen any changes. How long should I keep doing something in my routine before I should expect any positive improvements? A week? A month? A couple of months? Something else? And, while I'm at it, is there a general rule of thumbs for other products as well? Thanks in advance!
Girls Blog 2015
Submitted by etherealcalc