Hello, I am one of the owners of a laser hair removal office in Arkansas. I hope I can help you a little.
Because laser hair removal works on only the hairs in one stage you will have to have several treatments in order to catch several hairs in the right stage. One treatment will not remove all the hair just around 30% of it. You will still see growth because you will need more treatments. How many ??? Everybody responds differently. We usually tell our clients with very white skin between 4-6 treaments before they are happy. More treatments if they want most of the hair removed.
As to the darker skin that really isn’t a problem for a ND yag laser which can be used on black skin without burning the skin and still work on the hair. However the darker skined person will need to return more times to have the same results as a very white skined/dark hair person.
The reason is that the laser can’t be turned up as high on the darker skin because it will burn the skin.
Hope this helps.
Good luck in finding a ND Yag in your area.