What is PLLA?
PLLA is Poly L Lactic Acid. It has been used for decades. It started as a large volume filler for the face, used for those with a lot of facial volume loss like seen in early HIV patients. PLLA is made from lactic acid, which is a naturally occurring organic acid. It is biodegradable (it breaks down safely in the body), biocompatible (it does not trigger an immune reaction), and synthetic. Sculptra is the most widely recognized brand.
Why is PLLA a biostimulator?
PLLA is used as a regenerative agent as it starts a precise biologic sequence.
- The microparticles cause a mild, self limited inflammatory reaction
- It stimulates M2 macrophages, critical for tissue remodeling and anti inflammatory signaling
- Macrophages and monocytes go into the tissue, releasing growth factors.
- They also cause fibroblasts to make Type 1 collagen, glycosaminoglycans, and elastin
- Histology shows increased dermal density
- Timeline: 1st week- inflammation, 2-6 weeks fibroblasts and matrix deposition, weeks 6-16 is collagen maturation and reorganization.
So it is thought to increase dermis thickness, recover biomechanical integrity, and help with long term structure and functional rejuvenation of the skin.
How is PLLA used? Journal article
This was a study in the Aesthetic Surgery Journal, October 2025, “Poly L Lactic Acid in Aesthetic Dermatology: A Decade Beyond Volume Restoration toward Regenerative Biostimulation.”
This article looked at 63 studies between 2013 and 2025, focusing on its biostimulation, rather than as a filler. They looked for terms- PLLA, poly l lactic acid, collagen stimulators, regenerative dermatology, aesthetic rejuvenation.
Notable findings:
- New techniques decrease issues. Higher dilution protocols and cannula use have decreased vascular issues, nodules, and papules. Dilution now is up to 20cc/vial (Originally it was 7cc/ vial, mixed days in advance to reduce issues).
- It is not used as a filler. It is being used more often for dermal laxity, particularly for those with rapid weight loss on GLP.
- It is being used more broadly in the body– neck, upper arms, thighs, buttocks, and abdomen to improve skin texture, firmness, and hydration. These are difficult areas often because of motion, thin dermis, and variable fat distribution.
- It is being used with blunt tipped cannulas and fan shaped retrograde threading to give wide dermal coverage with low complications.
What is new PLLA protocol?
Protocols vary by where applied, skin condition, and patient goals. Typical protocol:
- Usually you do 2-4 sessions, spaced 4-6 weeks apart. You don’t notice changes until after the second session, with peak results 3-6 months after treatment
- Face: uses 5-9cc dilution per vial
- Body: uses up to 20cc per vial for broad coverage
- Injection depth is critical- Supraperiosteal or deep subdermal planes for face structure support. Superficial planes are needed for laxity of the skin, like inner arms and thighs
- Lidocaine or bicarb are sued to help make more comfortable and limit inflammation
- In the past it was said to do 5 minutes of massage, 5 times a day, for 5 days. With these new dilutions, it thought that is not as critical
Combinations may have synergy
- PLLA with microneedling– either before or after- may help distribute the PLLA and may help immune cell access to microparticles
- PLLA with fractional lasers may have statistically significant increase in dermal thickness vs monotherapy
- Biostimulatory layering with HA fillers, lets you give structural support with the JA and improvement of skin quality with the PLLA.
Is there a downside to PLLA?
There are side effects which seem to be better with the new protocols. Issues seen are nodules, granulomas, and transient problems like redness, bruise, and swelling. Using cannulas helps reduce vascular trauma.
My biggest issue with PLLA is that it inhibits fat graft survival. So using it in the skin to help with skin quality would be okay. Using it more deeply for its filler effect for sure leads to issue with future fat grafting- it is putting clay in my soil. The fat does not plant and survive well.
Dr. Greenberg’s thoughts on PLLA
I am mixed on this. I hear the “biostimulatory” effects, and I am a fan of regenerative medicine and newer technologies. I do a lot of nanofat, stem cell, and exosome use. But I have seen firsthand how people who have had PLLA injections- most of them deeper in the tissue- do not have good fat grafting survival. And I LOVE fat grafting. And remember PLLA is synthetic. I love using your own tissue if you can.
There is some thought it may help with epigenetics and reprogram fibroblasts and skin rejuvenation. Some newer studies show in animal models that PLLA treated fibroblasts have sustained upregulation of certain markers. Those findings are exciting and would change my thought process if found to be true for humans.
If injecting with a cannula, you are going below the skin. That by definition is placing it in the subdermal fat. The collagen created is akin to scar tissue.
So jury is out for me. I could see using this in areas which don’t respond to other treatments like microneedling with exosomes, or fat grafting with microfat and nanofat. There are some patients who don’t have enough fat, fat has failed in the past, or want to treat an area where I wouldn’t normally treat- the inner arm, the area above the knee.
But for me, microneedling with exosomes and fat grafting are better. I would try those first.
Medical citation
Poly-L-Lactic Acid in Aesthetic Dermatology: A Decade Beyond Volume Restoration Toward Regenerative Biostimulation, Aesthetic Journal 2025
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