It is difficult to say exactly how long a procedure may take as there are many degrees of hair loss and factors that are taken into consideration when completing a transformation.
Normally, sessions are 3 to 4 hours in length when trying to recreate the hairline and/or rebuild hair illusions to the top of the head.  While scars are typically 1.5 to 2-hour sessions, again depending on the severity of traumatized area.  Scalp micropigmentation is a multi-session procedure usually 3 sessions schedule approx. 7 days apart are required to perfect your transformation.  Exact time does vary depending on individual requirements. Sessions are repeated until the demarcation line between your new hair illusions can no longer be distinguished from existing hair follicles, if present.