PLLA (Poly-L-lactic acid)
This document is technical information about materials. It does not recommend any procedure or product.
In brief
A synthetic biodegradable polyester used as a dermal biostimulatory material. Unlike the racemic form, it is built from a single stereoisomer and is semi-crystalline, which is associated with slower hydrolytic breakdown.
Regulatory identity by market
COS cosmetic · MD medical device · RX drug · — not established in public sources
Identity & physical properties
| Synonyms | Poly-L-lactic acid, Poly(L-lactide), PLLA |
|---|---|
| Formula | (C3H4O2)n |
| Family | Biostimulator — aliphatic polyester |
| Particle size | Reported in the tens of micrometres for injectable microparticle forms; varies by manufacturer |
| Morphology | Semi-crystalline microparticles. Injectable forms are described in the literature as lyophilised powder reconstituted before use |
| Molecular weight | Varies by grade; not standardised across the aesthetic literature |
Mechanism
Reported literature describes a foreign-body response to the polymer particles with macrophage involvement, followed by fibroblast activity and collagen deposition. Animal work has reported M2 macrophage polarisation accompanying dermal collagen synthesis in aged skin.
Evidence
| PMID | Study type | Summary |
|---|---|---|
| 38206151 | RCT | Randomised controlled trial of an injectable PLLA implant versus no treatment for cheek wrinkles |
| 39339028 | review | Systematic review of PLLA in facial aesthetics, restricted to randomised clinical trials |
| 41184662 | review | Systematic review of efficacy, durability and safety of PLLA- and CaHA-based collagen biostimulators in the face |
| 37174720 | in vivo | PLLA improved dermal collagen synthesis via M2 macrophage polarisation in aged animal skin |
Regulatory identity — detail
| Market | Classification | Note | Basis |
|---|---|---|---|
| KR | medical-device | Injectable forms follow the tissue-repair biomaterial route in the MFDS device classification notice. | Legal text |
| EU | medical-device | Annex XVI, Section 3 of the MDR covers substances intended for facial or other dermal filling by injection, bringing such products under the Regulation even without an intended medical purpose. | Legal text |
| US | medical-device | An injectable PLLA dermal implant holds FDA premarket approval under PMA P030050, listed with the generic name 'implant, dermal, for aesthetic use'. This is the device pathway, not the drug pathway. | 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
Reconstitution volume and the interval before injection differ between published protocols and are not standardised. Direct comparisons against the racemic form are scarce, so differences in degradation behaviour are largely inferred from polymer chemistry rather than measured head to head. Most published work concerns injectable forms and does not transfer automatically to topical formulations.
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.
PLLA and the racemic PDLLA share the same repeat unit but differ in stereochemistry: PLLA is built from a single stereoisomer and can crystallise, while the racemic form cannot and stays amorphous. The literature associates this difference with degradation rate, but the two are rarely compared directly in the same study.