What is the intended user age range for the REVIAN RED system? Jesse S. February 10, 2020 20:14 REVIAN users must be at least 18 years old. There is no upper age limit. Related articles My hair is thinner and finer than it used to be, will the REVIAN RED system make my hair thicker? How effective is this treatment for someone with a bald spot in the back of the head? Comments 0 comments Please sign in to leave a comment.