CO2 does more per session for boxcar scars and general roughness. RF microneedling is preferred where scarring comes with laxity, where skin tone makes ablative treatment risky, or where a week of downtime isn't possible. But the question patients should ask first isn't which device — it's whether their scars are tethered. Because if they are, neither device will fix them.
Start With the Stretch Test
Before comparing devices, spend ten seconds establishing what you're actually treating. This determines more about your outcome than the choice between CO2 and RF.
Tethered. A rolling scar. Fibrous bands beneath are pulling the skin down.
Not tethered. Boxcar or ice pick — true tissue loss with defined edges.
If it flattens, resurfacing will not fix it. You can smooth the surface as many times as you like; the thing pulling it down was never touched. That component needs subcision.
Most patients find they have both types in different areas of the face — which is why a plan usually involves more than one technique.
Why Laser Disappoints People
The most common story I hear about previous acne scar treatment isn't that it failed. It's that it helped, and the patient is still unhappy.
They completed a course of laser or RF. The texture genuinely improved. The pores look better. And the same depressions are still visible in the same lighting.
That's not a treatment failure. It's a diagnosis failure. A resurfacing device did what resurfacing devices do, on scarring that needed something else — and nobody separated the two before starting.
By Scar Type
flattens when stretched
sharp vertical edges
narrow and deep
roughness, pores
looser skin alongside
smooth to the touch
firm, elevated
Four of seven rows say neither. That's not an argument against resurfacing — it's an argument for identifying what you have before choosing a device. Ice pick scars need TCA CROSS or punch techniques. Flat brown marks are pigment and need Pico laser. Raised scars need corticosteroid, and collagen-stimulating treatment can make them worse.
Where the Two Devices Genuinely Differ
CO2 does more per session
Ablative fractional CO2 combines tissue removal with deep thermal delivery, and produces greater collagen stimulation per treatment than RF microneedling. For boxcar edges and general textural roughness on the face, it's the stronger tool — typically two to three sessions where RF needs three to five.
The cost is five to seven days of real recovery, and meaningfully higher pigmentation risk above Fitzpatrick IV.
RF wins on three specific things
Deeper skin tones. Energy delivered below the epidermis rather than through it lowers post-inflammatory hyperpigmentation risk considerably. For Fitzpatrick IV and above, this is usually the right resurfacing choice.
Scarring with laxity. RF tightens as it remodels. If the face has both textural scarring and early looseness, one treatment addresses both.
Downtime. Two to three days versus five to seven. For patients who genuinely can't disappear for a week, this isn't a compromise so much as the only workable option.
Neck and jawline scarring: if acne scarring extends onto the neck, RF is the appropriate choice there regardless of what's used on the face. Neck skin has fewer structures available for healing after ablative treatment and tolerates CO2 poorly. More on the area-by-area differences.
The Sequence That Actually Works
For a face with mixed scarring — which is most faces — the device question is secondary to the order of operations.
At Plump, steps two through four are frequently performed in a single session — release, fill, resurface, in that order — rather than across separate appointments with separate recoveries.
What to Expect
Sessions. CO2 typically two to three, six to eight weeks apart. RF typically three to five, four to six weeks apart. Where subcision is involved, two to four sessions is common depending on the extent of tethering.
Timeline. Collagen remodeling continues for three to six months after each session. The result at three months isn't the final result, and judging it earlier than that is not useful.
Ceiling. Meaningful improvement in depth and texture. Not erasure. Scarring that formed over years doesn't resolve completely, and anyone promising smooth skin from a single protocol is overselling. Patients who understand that going in are consistently the ones happiest with what they get.
Bring your history. If you've had resurfacing before and plateaued, that's useful information — it often means the textural component was addressed and the tethered component wasn't. A patient who's completed three sessions of RF with limited change frequently doesn't need a fourth. They need a different technique.