What About Silhouette Lifting? Duration and Side Effects

Key summary. Silhouette lifting is a non-surgical lifting method that inserts absorbable threads (such as PDO) beneath the skin, using hook-shaped protrusions (barbs) to catch the tissue and pull it upward. A randomized controlled trial published in 2025 reported that, regardless of the number of threads used (3 per side vs. 6 per side), the early lifting effect seen at day 20 had disappeared by day 60. Among the lifting procedures, silhouette lifting has an especially small body of published clinical literature (mostly case series), so this article discloses upfront that it contains more unconfirmed items than other articles.

What this article covers

• Comparison criteria: material (PDO, etc.) · number of threads and insertion method · evidence for duration · complication rates
• Caution: there are a great many brands (materials, structures, and procedure techniques all differ), and each is regulated as an individual approval by country, so "silhouette lifting" cannot be discussed as a single unified approval
• Evidence status: 1 RCT (60-day follow-up, small scale) · 1 complication meta-analysis (26 studies · 2,827 patients) · multiple literature reviews; as of this article, no controlled study demonstrating long-term sustained effect has been confirmed

Key points

1. Definition: absorbable threads (mainly PDO) are inserted beneath the skin, and hook-shaped barbs catch and pull the tissue, aiming for both a physical lifting effect and a subsequent collagen-stimulating effect.
2. Who it's for: it is generally introduced as a non-surgical option for mild to moderate sagging, but as of this article, no controlled study supporting long-term efficacy has been confirmed.
3. Order of verification: thread material/brand and approval status → practitioner qualifications → whether the stated effect was measured at what day → guidance on pain, side effects, and absorption.

01How It Works

Silhouette lifting uses absorbable sutures (mainly polydioxanone, PDO) engraved with tiny hook-shaped barbs; once inserted beneath the skin and pulled from the opposite end, these barbs catch the surrounding tissue and pull it upward. This physical traction itself produces an immediate lifting effect, and the foreign-body reaction that occurs as the thread is subsequently absorbed is said to stimulate collagen production, producing an additional effect. Besides PDO, thread materials also include PLA (polylactic acid) and PCL (polycaprolactone), and in Korea, multiple brand products differing in material, thickness, barb structure, and length are each distributed under separate individual medical device approvals (mainly in the "absorbable suture" category). For this reason, the procedure "silhouette lifting" itself cannot be verified under a single approval number — during consultation, you must separately ask about the brand and material of the thread actually being used and whether that specific product is approved.

02What the Research Confirms and Does Not Confirm

The figures above were confirmed as of 2026-09-19 (both the RCT and the meta-analysis were read in full). It should also be considered that the 60-day follow-up period is short. The authors of this RCT themselves stated that "the follow-up period of only 20 and 60 days is a limitation for confirming long-term sustainability or the delayed effect of collagen stimulation." In other words, the controlled studies available so far cannot answer whether there is an effect "months later, or a year later" — what has actually been confirmed leans closer to the finding that "the early effect was already diminishing by day 60".

Another finding from this meta-analysis is that complications differ in character depending on when they appear. Doctors distinguished between early complications that appear within 4 weeks of the procedure, such as swelling, pain, and bruising, and late complications that appear after 4 weeks, such as a palpable or visible thread, skin dimpling, or thread migration, and pointed out that the late complications may be the more clinically meaningful problem. When asking about side effects during a consultation, it is also worth checking separately for "what is common right after the procedure" versus "what only becomes apparent weeks later."

03Items to Check Before the Procedure

04Choosing by Condition

• Want a short recovery without incisions → Consult and compare thread lifting alongside other non-surgical options (Ulthera, Thermage, Shurink, etc.)
• Offered a suggestion to increase the number of threads → Confirm during the consultation that there is no established evidence that a higher number of threads extends the duration of effect
• Long-term duration of effect matters to you → Be aware that the longest follow-up among controlled studies confirmed so far is 60 days, and compare against surgical methods as well

05Common Misconceptions

"More threads mean a longer, stronger pull" — In an RCT involving 22 participants, doubling the number of threads (6 vs. 12) showed no statistically significant difference in volume change, tissue movement, or satisfaction. This study found no evidence that increasing the number of threads always leads to better results.

"Thread lifting effects last a long time because of collagen stimulation" — In this RCT, the lifting effect (physical traction) observed at day 20 tended to have already diminished by day 60. The doctors interpreted this as meaning that the thread's mechanical traction force alone may not be enough to sustain tissue movement, and this study did not confirm that the delayed effect from collagen stimulation is large enough to offset that decline.

"Side effects are rare" — In a meta-analysis pooling 26 studies, the frequency of common side effects, such as swelling at 34% and bruising at 26%, was by no means low. That said, it should also be kept in mind that definitions and follow-up periods vary greatly across studies, resulting in very high heterogeneity — these figures should be read as a reference range rather than taken at face value as "a X% probability."

06In Summary

Thread lifting has a clear mechanism, physically hoisting tissue with the barbed hooks on the thread, but the only controlled study (RCT) identified for this article was a single small study with 60 days of follow-up, and even its results leaned toward "the initial effect diminishes by day 60." There is also no evidence that increasing the number of threads increases effectiveness. Complications (swelling, bruising, palpable threads, etc.) are by no means rare according to the meta-analysis. Rather than focusing on "how many threads are inserted," the more sensible order of priorities is to first check whether the brand and material are actually approved products, and how many days after the procedure the stated effect was measured.

07Frequently Asked Questions

What is the mechanism behind thread lifting's effects?

The mechanism is explained in two parts — the primary effect is physical traction, in which barbed hooks cut into the absorbable thread catch subdermal tissue and hoist it, and an additional effect comes from the foreign-body reaction triggered as the thread is absorbed, which stimulates collagen production. In other words, an immediate traction force and a regenerative response that emerges over time work together.

Does inserting more threads produce better results?

No, that is difficult to support. In an RCT involving 22 participants, doubling the number of threads (6 → 12) showed no significant difference in volume change, tissue movement, or satisfaction. If you are offered a suggestion to insert more threads, it is worth asking what the basis for that suggestion is.

How long do the effects of thread lifting last?

That has not yet been confirmed — the longest follow-up period among controlled studies published so far is only 60 days, and even at that point the initial lifting effect had already shown a tendency to diminish. Whether the effect lasts beyond that has not been supported by any controlled study.

What Side Effects Are Common with Thread Lifting?

A meta-analysis pooling 26 studies and 2,827 patients found swelling at 34%, bruising at 26%, thread palpability or visibility at 10%, and skin dimpling at 7%, in that order. However, the variation between studies is large, so these figures should be viewed as a reference range rather than fixed numbers.

How Do You Check Domestic Approval for Thread Lifting?

"Thread lifting" is often used as a single umbrella term, but it actually refers to a range of thread products that differ in material and brand — so you should first confirm the exact brand name of the thread being used, and then separately ask whether that specific product has individual medical device approval.

08Pre-consultation checklist

• □ Confirmed the brand name, material, and approval status of the thread being used
• □ Confirmed the medical staff actually performing the procedure and their qualifications
• □ Confirmed how many days after the procedure the presented efficacy evidence was measured
• □ Asked for the basis behind any suggestion to increase the number of threads
• □ Received written guidance on side effects such as swelling, bruising, and thread palpability, and the response procedures for them

09Glossary

• RCT (Randomized Controlled Trial): A relatively high-reliability study design in which participants are randomly divided into groups for comparison.
• Controlled study: A study that includes a separate comparison group (control group) against the treated group. Without a control group, it is hard to tell whether an observed improvement is due to the procedure or another cause.
• Meta-analysis: An analysis method that statistically combines the results of multiple individual studies to draw a single conclusion.
• Heterogeneity: A measure of how much results vary from study to study. High heterogeneity makes it difficult to combine multiple studies into a single calculation.

10Sources and verification date

• PMID 40236886 — Verified 2026-09-19. A randomized controlled trial of 22 patients (44 sides), PDO threads 6 vs 12 threads, followed for 20 and 60 days. No conflicts of interest, no research funding; the thread brand used was iThread (Brazil), which may differ from products distributed domestically.
• Meta-analysis (PMC13076318) — Verified 2026-09-19. Pooled 26 studies and 2,827 patients, synthesizing complication rates. No conflicts of interest; explicitly states no generative AI was used.
• The studies above are reference material for understanding the mechanism and evidence status of the procedure and do not guarantee any specific clinic, practitioner, thread brand, or outcome.

11Editorial responsibility and interests

• Written by: Korea Beauty Report Editorial Team · Editorial responsibility: Korea Beauty Report Editorial Team
• Review scope: The editorial team prepared this content from published research and public data. It was not separately reviewed by a medical professional and does not replace individual diagnosis or treatment.
• Conflicts of interest: No contracted or advertising clinic relationship in this article
• First published: 2026-09-25 · Last fact-checked: 2026-09-25