Polylactic acid: what it is and how it works in HOF

Poly-L-lactic acid (PLLA) is a synthetic, biocompatible, absorbable polymer, from the same family of materials used in suture threads. In orofacial harmonization (HOF) it is used as a collagen biostimulator: instead of filling directly, the microparticles trigger a controlled inflammatory response that stimulates fibroblasts to produce new collagen.

The product usually comes as a powder to be reconstituted before use, according to the package insert. Over time, the body breaks the particles down, and the effect that remains is that of the collagen formed.

What is it usually indicated for?

The most frequently cited indications are diffuse volume loss and mild to moderate laxity, in areas such as the cheekbone, temples and jawline. The result is gradual and generally requires more than one session, with intervals defined by the qualified professional, after assessment. The duration described is usually long, and varies by patient.

How does it differ from hyaluronic acid?

Hyaluronic acid gives immediate volume and can be reversed with hyaluronidase. Polylactic acid works indirectly, takes time to show an effect and has no enzymatic reversal. For that reason, the indication and the amount call for careful planning.

Which risks should be considered?

Swelling and bruising are common. Nodules and papules are the best-known complication, linked to factors such as dilution, plane and distribution of the product. Vascular occlusion is also possible, as with any injectable. Injecting into areas of highly mobile muscle, such as the lips, is usually avoided.

Also known as: PLLA, poly-L-lactic, poly-L-lactic acid.