The main ingredient in Sculptra is poly-L-lactic acid (PLA). It is poly-L-lactic acid that makes Sculptra so unique among dermal fillers. PLA is a synthetic dermal filler made from a polymer of lactic acid molecules. While it is synthetic, lactic acid occurs naturally throughout the body. In poly-L-lactic acid, individual molecules of lactic acid are hooked together in long chains and branches.
This branching serves two purposes. First it provides volume to Sculptra, allowing it to occupy space beneath the skin. Second, since the lactic acid is united in long chains, enzymes in the skin have a hard time breaking down Sculptra. This means that Sculptra is not cleared from the body as quickly as simple lactic acid injections would be.
Sculptra obtained FDA approval as a treatment for lipoatrophy occuring as a side effect of some HIV medications. It seems that people being treated with protease inhibitors tend to lose subcutaneous fat, that is, fat just below the surface of the skin. Lipoatrophy, it turns out, is not only caused as side effect of a medication.
Lipoatrophy is literally fat atrophy. Similar to the way that muscles atrophy when they are not used, many tissues in the body atrophy over time. Lipoatrophy occurs as we age. All of us will lose subcutaneous fat as we get older and, in fact, the process of fat loss starts in our 20s. This fat loss causes our faces to sag and wrinkle and the veins underneath the skin are more easily seen, since the layer of fat covering them is thinner.
Most dermal fillers simply provide volume to an area—their volume fills in the subcutaneous area and lifts the skin up and away from the underlying tissue. Sculptra does that, to be sure, but also stimulates the body to react to it, which is a unique property among dermal fillers. The PLA microcrystals in Sculptra cause the immune system to mount an inflammatory reaction which produces collagen around the PLA. Most dermal fillers will reach their fullest within about two weeks. Because of the inflammatory reaction, the filling results of Sculptra can increase for weeks or months.
Readers may be concerned about the inflammatory reaction caused by Sculptra. PLA does not cause an allergic reaction, with hives, itchiness, and perhaps breathing problems. The naturally occurring lactic acid does not stimulate an atopic response unless a person is specifically allergic to one of its components.
While Sculptra does plump up an area immediately after injection, the filling effect is not as robust as it is in other dermal fillers—at first. The swelling that is experienced initially will subside within a day or two. The inflammatory response will take some time, perhaps several weeks. Most people see the maximum benefit of Sculptra after eight weeks and these results should last up to two years, a duration of effect that far exceeds other dermal fillers.