You have numerous hair follicles throughout you skin and not all these are in active growth cycles (Anagen phase)-some are dormant. Laser hair removal, when performed properly, will destroy hair follicles when they are in the Anagen phase and this is theoretically permanent for that follicle. Numerous surrounding follicles may be in other phases and they will eventually begin to grow making it appear that the hair removal treatment was unsuccessful. It is recommended that follow up treatments be preformed to address any hair regrowth. I have had a few clients that had no growth for up to a year before the treated area saw regrowth.Testosterone hormone therapy at the doses for gender dysphoria treatment will cause male pattern hair growth patterns in genetic females, but these hair follicles are just as susceptible to laser removal as any other.I hope that helps answer your question