A familiar pattern
Someone arrives having already done the work. Three, four, sometimes six sessions of RF microneedling elsewhere. The first one or two produced real improvement — texture better, skin looking healthier. Then it stopped. Each subsequent session gave back less than the one before, and they're now wondering whether to book more, switch devices, or accept it.
None of that is a failure of the treatment or of whoever performed it. It's a mismatch between where the treatment works and where the problem lives.
RF microneedling works in the dermis. Radiofrequency energy delivered through microneedles stimulates collagen in the mid-to-deep dermis. That's genuinely valuable — denser collagen improves texture, firmness, and surface quality.
Rolling scars are anchored below the dermis. Fibrous bands running between the dermis and the tissue beneath physically tether the skin surface and pull it down.
The dermis above a tether can be made as dense and collagen-rich as you like. The tether beneath will still pull. A collagen stimulus doesn't solve a mechanical anchor.
What RF does and doesn't reach
RF microneedling is a good treatment, and this isn't an argument against it. It produces real improvement in skin quality, texture, pore appearance, and shallow scarring, and it's appropriate across a broader range of skin tones than ablative resurfacing. The limitation described here is specific to one scar type.
Why improvement stops
The first sessions produce visible change because there's genuine surface-level work available. Collagen density rises, texture evens out, shallow edges soften.
Then the surface work runs out. Whatever remains is being held down from below, and additional sessions can't reach it. The returns diminish not because the treatment stopped working, but because the remaining problem was never in the dermis.
At that point the useful question changes from "how many more sessions?" to "is there tethering that hasn't been addressed?"
The stretch test answers it in ten seconds. Pull the skin taut beside a scar. If it softens or partly disappears under tension, you're temporarily releasing the same band that pulls it down at rest — that's active tethering, and no amount of resurfacing replicates that release.
If the scar looks identical under tension, tethering isn't your limiting factor, and continuing with resurfacing is reasonable. More on identifying scar type.
What subcision does differently
A blunt cannula is passed beneath the scar under local anaesthesia and moved in a fanning motion, dividing the fibrous bands. The skin is released and sits where it should. A biostimulator is commonly placed into the released space — partly to occupy it, partly to encourage collagen formation rather than re-adhesion.
It's a mechanical solution to a mechanical problem, which is why it works where resurfacing plateaus.
Bruising is expected and can be substantial. You are dividing tissue beneath the skin — bleeding into that space is part of how it works. Bruising typically lasts one to two weeks and is genuinely visible. Swelling in the first several days is also normal.
That's considerably more disruptive than the two or three days after RF microneedling, and it needs planning around. Patients who book without knowing this are unhappy in week one regardless of how good the eventual result is.
Tethers can partly re-form. Healing tissue can re-adhere, which is why biostimulator is placed in the space and why more than one session is commonly needed.
Improvement is partial, not complete. Rolling scars generally improve substantially rather than disappearing. Anyone describing subcision as a one-time cure is overselling it.
Not either-or
These treatments work at different depths and combine well. The usual sequence is subcision first to release the tethering, then resurfacing to refine the surface above it — the structural problem solved before the surface is polished.
Continuing to repeat resurfacing alone, once tethering has become the limiting factor, is the thing that doesn't help. That's the specific situation this page is about, not a general argument against RF microneedling.
On the biostimulator: using a collagen biostimulator such as Sculptra in acne scarring is off-label — it's FDA-approved for facial volume restoration rather than for this indication. Off-label use is common and legal throughout medicine, and it's worth knowing rather than discovering later.
What to do with this
Do the stretch test and note which scars change. If several soften under tension after multiple resurfacing sessions, tethering is the likely explanation for the plateau and subcision is the step that addresses it — with the downtime described above factored in.
If nothing changes under tension, the plateau means something else, and more subcision isn't the answer either.