Polycaprolactone (PCL) typically comes as PCL microspheres held in a carboxymethylcellulose (CMC) gel. Both components are fully biodegradable.

The CMC gel provides an immediate filling effect after injection, but it is absorbed over the next few months typically. The PCL component stimulates collagen production and provides a secondary filling effect as the CMC gel is being absorbed. Optimal collagen production may occur 3 to 6 months after the initial injection. The secondary filling effect can last for 1 to 2 years.

When appropriately administered, PCL can deliver natural, lasting results. However, the collagen when produced too superficially can result in nodules. This may occur from PCL being placed too close to the skin, or at areas where there isn’t much fat, like the undereye or the forehead.

As PCL cannot be dissolved (unlike HA dermal fillers using hyaluronidase), we avoid injecting PCL to at-risk areas like the undereye area and we also do not advocate doing multiple syringes of PCL to the same area at a single sitting.

PCL is also a particulate dermal filler, as such it does carry the risk of causing Filler-Induced Vascular Occlusion (FIVO), and vascular events from the administration of PCL have been documented.