This is my absolute favorite hair product I own. I have naturally wavy, but SUPER frizzy hair. If I even just sit still doing nothing, my hair will become really frizzy, and really tangled. This serum, however does a great job of smoothing my hair out and decreasing frizz. I do usually use more than suggested: it says to use one pump, but I use too. I also have pretty long hair though. Another thing is that it suggest you can use it on wet hair before blow drying. However I find that this works best for me on dry hair and that it doesn't really help decrease my frizz by the time my hair is dry if put it on wet hair. So I usually just put this on my hair as a last step after styling and hairspray, or if I'm just doing natural hair, I put it on as a last step to control my hair and make natural waves actually look good. This would probably also work well on straight or curly hair - just anyone who wants to smooth and control their hair.