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Recently, many clients and other doctors have been asking me about Poly-L-lactic Acid (PLLA), and I believe some readers are also interested in this topic. However, this topic is quite academic, and readers without a chemistry background may find it difficult to understand. So, I hope to explain it in a simple way to make it easier to understand.

PLLA stands for Poly-L-lactic Acid, which is a type of “polymer” that is formed by the polymerization of multiple lactic acid molecules. Smart readers may ask, “If there is Poly-L-lactic Acid, then there must be Poly-R-lactic Acid too, right?” Yes, there is Poly-R-lactic Acid, and there are significant differences between the left and right forms!

Currently, the only available “Poly-L-lactic Acid” on the market is Sculptra®, which was approved by the FDA in 2004 for the treatment of lipodystrophy in HIV patients. In recent years, this type of lactic acid has also become popular in aesthetic medicine as a filling agent. Recently, there is a product claiming to be a second-generation PLLA, and several doctors and clients have asked me about this product. Curious, I did some research and found that this so-called second-generation product is actually “Polylactic Acid” instead of the commonly used “Poly-L-lactic Acid”. Let’s discuss the chemical composition of “Polylactic Acid” below.

Lactic acid is a common substance in the body, and “Polylactic Acid” is a “polymer” formed by the polymerization of multiple lactic acid molecules. The chemical and physical properties of “polymers” are completely different from those of a single lactic acid molecule. Before explaining “Poly-L-lactic Acid,” I want everyone to understand that some molecules can be “left-handed” or “right-handed.” “Levo-” represents “left,” and “dextro-” represents “right.” They have the same molecular formula and sequence, but the only difference is the direction of their 3D structure, just like a mirror image. You may ask, “In the end, isn’t it the same substance whether it is left or right?” The properties of substances can be different depending on the direction. That’s why the product is labeled as “Poly-L-lactic Acid.” “Poly-L-lactic Acid” is the polymerized left-handed lactic acid, and its properties are different from those of “Poly-R-lactic Acid.” Lactic acid in the body is left-handed, so the body can break it down into carbon dioxide and water without toxicity. Therefore, “Poly-L-lactic Acid” is a commonly used substance in the medical field, and Vicryl surgical suture is made of “Poly-L-lactic Acid.”

As for the product claiming to be a new generation product, I checked their product information and only found that their ingredient is “Polylactic Acid” without specifying whether it is “left-handed,” “right-handed,” or a mixed polymer. Their new product only has a few medical reports sponsored by their company and no other literature support, and its long-term side effects are unknown.

With all the left and right, and various chemical names, it may not be easy to understand, but what’s most important is to consult your doctor if you have any questions.