Subcision after a facelift can be safe in selected cases, but timing and depth matter. It is usually considered only after the facelift tissues have healed and softened, and only for a clear problem such as a tethered scar, depression, or localized adhesion. A careful, limited subcision should not normally make the whole face sag. The concern is that aggressive release, treatment too early, or work in the wrong plane could disturb scar support, create contour irregularity, swelling, or compromise the lifted tissue. The safest step is to ask your facelift surgeon first, because they know the surgical planes used and whether the area is ready for any release.