PDO (Polydioxanone)
This document is technical information about materials. It does not recommend any procedure or product.
In brief
A synthetic absorbable polyester long used in surgical suture, and the material behind most absorbable lifting threads. It is unusual in this reference because its aesthetic use is mechanical first — a thread placed to reposition tissue — with a biostimulatory response reported alongside it.
Regulatory identity by market
COS cosmetic · MD medical device · RX drug · — not established in public sources
Identity & physical properties
| Synonyms | Polydioxanone, PDO, PDS, Absorbable thread |
|---|---|
| Formula | (C4H6O3)n |
| Family | Absorbable polyester — thread |
| Morphology | Supplied as monofilament thread, with barbed, cog and multi-strand configurations described in the literature; also as volumising thread constructs |
| Molecular weight | Not standardised across the aesthetic literature; thread gauge and configuration are the specifications usually reported |
Mechanism
Two effects are described and they should not be merged. The mechanical one is repositioning of tissue by an anchored thread. The biological one is a foreign-body response to the absorbable polymer, and an animal study cited here measured type I and III collagen after placement of polydioxanone alongside poly-L-lactic acid.
Evidence
| PMID | Study type | Summary |
|---|---|---|
| 38584576 | in vivo | Animal model measuring type I and III collagen biosynthesis after placement of poly-L-lactic acid and polydioxanone biostimulators |
| 38679891 | review | Review of thread lifting materials, distinguishing them from conventional sutures and covering composition and configuration |
| 38514895 | review | Review of volumising thread constructs and their development |
| 31267809 | in vivo | Clinical experience series with barbed polydioxanone cog threads, reporting complications and a technique intended to prevent them |
Regulatory identity — detail
| Market | Classification | Note | Basis |
|---|---|---|---|
| KR | medical-device | Absorbable thread and suture products follow the device route in the MFDS classification notice. | Legal text |
| EU | medical-device | Falls under the MDR. Note the difference from the injectable materials in this reference: Annex XVI covers substances introduced by injection for filling, whereas thread products are handled under the general provisions of the Regulation. | Legal text |
| US | medical-device | Absorbable polydioxanone sutures are listed as devices cleared through the 510(k) premarket notification pathway (for example K063680, 2007). What was verified is the suture indication; listings for individual aesthetic thread products were not established. | Legal text |
| JP | unclassified | Not established from public sources as of the revision date below. | — |
| CN | unclassified | Not established from public sources as of the revision date below. | — |
| VN | unclassified | Not established from public sources as of the revision date below. | — |
Limitations & open questions
Thread gauge, barb geometry, anchoring method and insertion plane differ between products and operators, and the mechanical result depends on all of them, so a clinical series describes a technique as much as a material. Separating the mechanical effect from the biostimulatory one is difficult in clinical reports because both occur together. Complications specific to threads — extrusion, palpability, asymmetry — are reported in the clinical literature cited here and have no counterpart among the injectable materials in this reference.
All statements on this page are drawn from the cited literature. Where a market’s regulatory classification could not be established from public sources, it is marked as not established rather than inferred.
Two effects that get reported as one
A thread lifts because it is anchored and pulls, and it provokes because it is an absorbable polymer the body reacts to. Clinical reports usually describe the combined result, which makes it hard to attribute an observed change to either mechanism on its own. When a claim about collagen is made for a thread, check whether the study measured tissue or measured appearance.
Where this sits among the polyesters
Polydioxanone belongs to the same broad family as the lactic-acid polymers elsewhere in this reference and is handled through the same regulatory route in Korea and the European Union. What differs is form. The others are placed as particles distributed through tissue; this one is placed as a single continuous strand along a plane, and the questions that follow — anchoring, extrusion, palpability — do not arise for a suspension.
The comparison study is worth reading directly
One animal study cited here placed polydioxanone and poly-L-lactic acid in the same experiment and measured type I and III collagen. That design is rare in this field, where most evidence for one material is generated without the other present. It is the closest thing to a like-for-like measurement available on this page.