There are people who have an hormone ailment that causes hair to grow continuously. These will make the laser treatment appear to be not working properly. The final question is how many treatments are needed to complete the procedure? To achieve the optimal result from laser hair removal, it usually needs 6 to 8 sessions conducted every 6 to 10 weeks. The hair type and some genetic factors affect the number of laser treatments needed. A consultation with a professional can determine what or if this is the case.