Thread lifting: we could not find a single randomised controlled trial

What we found instead: a retrospective chart review of 35 people, an uncontrolled observational study of 15, an animal experiment in guinea pigs, and a complication case series of seven. Several technique papers sit alongside these.

Not one randomised, controlled trial.

Let us be exact about what that means. It does not mean the procedure does not work. It means no study yet exists with a design capable of telling whether it works. A before-and-after result with no control is mixed in with swelling settling, with camera angle and lighting changing, and with knowing you were treated.

Radiofrequency and microfocused ultrasound at least have randomised trials pitting device against device. Thread insertion does not even have that.

The 2018 paper is a backwards look over twelve months of records. Thirty-five Asian patients received five 360° spiral cog threads per side.

Thirty-three (94.3%) were recorded as satisfied. Complications were few and resolved without surgery — but the authors noted that asymmetry was seen.

How to read 94.3% is what matters. This is self-reported satisfaction, with no control, collected retrospectively. Asking people who chose a procedure and paid for it whether they are satisfied almost always returns a high number. Because there is no comparison group who received a sham under the same conditions, nothing in this data can tell you whether the 94.3% is due to the procedure.

The 2023 study inserted threads vertically into the forehead and looked at how brow and eyelid position changed. Fifteen patients were photographed before, immediately after, and at 1 and 12 weeks, and the positions were measured.

A position measured from photographs beats a satisfaction questionnaire. But fifteen people, and no control group. At that sample size, a difference produced by chance is hard to separate from one produced by the procedure.

The 2017 study implanted fragments of barbed thread in the dorsal skin of 12 guinea pigs and took tissue at 1, 3 and 7 months.

A fibrous capsule formed around the thread, and type 1 collagen and TGF-β1 stayed significantly above normal skin across the whole seven months. Tissue reaction was strongest at one month and decreased gradually.

This supports a mechanism: the thread anchors firmly in tissue. But it is guinea-pig dorsal skin, it is histology, and it sits at a different level from how much a human face is lifted. Carrying lab and animal results across as if they were human effects is the most common leap in this field, so we grade it low.

Between August 2018 and July 2019, seven patients (three men, four women) presented with complications after PDO thread rhinoplasty performed at traditional-medicine clinics.

Three had severe disease with open wounds, abscesses and skin necrosis; four had milder redness and thread exposure. Six had undergone previous rhinoplasty, and ultrasonography showed abscess formation around the previously placed implant.

The authors make one clinically important point. PDO thread is invisible on imaging. At operation, the thread could not be found in any patient but one. Severe infections required extensive debridement and removal of the implant.

A seven-patient case series cannot tell you a rate. How often this happens is not knowable from this data. What it can tell you is what can happen.