I’m going to give you a quick answer and leave the great answer to someone else. The first thing you need to do and of course you won’t, is to not look for the first couple of weeks. If you do, you could be very disappointed and lose your baseline for determining whether or not the product is working.
Here’s the problem, the first thing you might see is loss of some hair. What? Yep, not everyone but some people go through an initial hair loss. Don’t panic and don’t stop using the product.
I’m guessing that many people are using a 5% product. It will take at least 3–4 months and sometimes up to 6 months of waiting to begin to see positive results. And really, it can take a year for the hair follicles to process through their cycles in order to provide you with a mirror image that brings a sigh of relief and a smile to your face.
Do remember that if you have certain medical conditions, it isn’t going to work at all.
And of course, this is kind of a life long use product if you want to sustain the regrowth.