By Sarah Hitchcox Aesthetics · September 6, 2026
“Collagen-stimulating” describes a proposed effect, but it does not tell you how that effect was measured. Some aesthetic treatments have been studied with skin biopsies before and after treatment. Reading those studies means looking at the participants, the treatment protocol and the outcome, alongside the headline number.
Collagen Treatments: A Knoxville Guide to the Evidence
Poly-L-lactic acid: a 14-person study
Goldberg and colleagues studied injectable poly-L-lactic acid in 14 healthy adults. This was an exploratory, open-label, single-arm study. Researchers examined skin biopsies at three, six and twelve months and compared collagen types I and III with baseline measurements. [1]
They observed increases in both collagen types at three and six months; the type I changes were statistically significant at both time points. Technical difficulties limited interpretation of the twelve-month findings. [1]
The published abstract does not give a 66.5% increase in type I collagen. That percentage should not be attributed to the abstract. To verify an exact percentage, a writer needs the relevant measurement in the full paper and its context. The abstract supports a measured type I collagen increase in this small study; it does not establish a predictable percentage improvement for an individual face. [1]
Poly-L-lactic acid is discussed here as a research comparison. This article is not a statement that Sarah Hitchcox Aesthetics offers Sculptra.
Microneedling: measurements in acne-scar treatment
El-Domyati and colleagues evaluated ten patients with atrophic acne scars during a course of six microneedling sessions over three months. Their assessment included photographs, clinical ratings and skin-biopsy measurements. The researchers reported increases in collagen markers and epidermal thickness, alongside improvements in scar appearance. [2]
The results concern that study's participants and protocol. They cannot be used to promise the same response from every device, treatment schedule or skin condition. The authors also called for larger and longer-term studies. [2]
What does this mean when comparing treatments?
Biopsy findings can support a biological effect, but they are not the same as a personal forecast of visible results. A small study without an untreated comparison group also leaves questions that a larger controlled study could address.
When an article cites a dramatic percentage, check what was counted, when it was measured and how many people were studied. A change in a collagen marker is not automatically the same percentage change in wrinkles or firmness. Different procedures should not be treated as interchangeable simply because their descriptions mention collagen.
For an individual treatment decision, discuss the exact procedure, expected benefit, risks and alternatives with the clinician performing the assessment.
Cite this page
Sarah Hitchcox Aesthetics. “What Actually Rebuilds Collagen? What the Biopsy Studies Show.” September 6, 2026. https://hitchcoxaesthetics.com/blog/what-rebuilds-collagen
Sources
- Goldberg D, Guana A, Volk A, Daro-Kaftan E. Single-arm study for the characterization of human tissue response to injectable poly-L-lactic acid. Dermatologic Surgery. 2013;39(6):915–922. doi:10.1111/dsu.12164.
- El-Domyati M, Barakat M, Awad S, Medhat W, El-Fakahany H, Farag H. Microneedling Therapy for Atrophic Acne Scars: An Objective Evaluation. Journal of Clinical and Aesthetic Dermatology. 2015;8(7):36–42.