Acne marks and acne scars aren't the same thing, and mixing them up leads to the wrong treatment. Marks are flat discolouration left behind after a breakout — pigmentation changes sitting on the surface, which tend to fade with time and respond well to peels or LED. Scars are structural: the skin's own repair process has left indentations or raised areas where a breakout damaged deeper tissue.
Microneedling works on the structural kind. Fine needles create a controlled, superficial injury that prompts the skin to rebuild its own collagen — gradually filling depressed scarring and refining the surface, rather than resurfacing or removing tissue outright.
The honest part: active breakouts need to be under control first, because needling over live acne can spread bacteria and cause further scarring. Most scarring also needs a structured series of sessions, not a single visit — your clinician will set a realistic count at consultation, based on scar type and depth.