Been getting assuage since early 2012. Every few months or so depending. If you wear your hair straight like I did while I was transitioning then you will get it more often in summer. Why, because you'll see the difference when humidity or water comes in contact with your hair. The untreated hair will puff up and not hold it's style. The treated hair can endure a lot of humidity. I must say that this is NOT a straightening system. It definitely makes your hair smoother. In my case it made my curl pattern softer and much more defined but by no means straight. Now that I am completely natural I still get the treatment (not as often) but I like what it does to my curls and if I decide to wear it straight I have the confidence of knowing that my style will hold up in humid weather.