How does a CO2 (carbon dioxide) laser stimulate collagen production?

How CO2 Laser Stimulates Collagen Production

Mechanism of Action

CO2 lasers stimulate collagen production through controlled thermal injury to the dermis, which triggers a wound healing cascade that results in both immediate collagen shrinkage and subsequent new collagen deposition (neocollagenesis) over weeks to months. 1, 2, 3

Immediate Effects: Thermal Collagen Modification

• CO2 laser energy (10,600 nm wavelength) is absorbed by water in tissue, creating photothermal effects that cause immediate collagen coagulation and shrinkage 1, 2
• The thermal damage penetrates into the dermis, with residual thermal damage (RTD) depth directly correlating with the degree of collagen contraction 3
• Heat-induced collagen shrinkage produces immediate tissue tightening, which contributes to clinical improvement by tightening loose skin and reducing wrinkles 2
• Collagen fibers undergo structural changes, with greater compaction and horizontal reorientation occurring when dermal RTD exceeds 70 micrometers 3

Delayed Effects: Wound Healing and Neocollagenesis

• The controlled thermal injury initiates a wound healing response that stimulates fibroblast activity and new collagen synthesis over the following weeks to months 4
• Histopathological studies demonstrate robust dermal fibrous tissue regeneration and neocollagen formation by 7 days post-treatment 5
• The combination of immediate collagen contraction and thermal damage modulates the wound healing process to produce long-term collagen remodeling 3

Depth-Dependent Effects

• Multiple passes with CO2 laser produce progressively deeper thermal damage and more extensive collagen coagulation 1
• Ten pulses of CO2 laser demonstrate the most effective collagen coagulation, while also increasing the mechanical strength of treated skin tissue 1
• Four passes with CO2 laser typically remove approximately 250 micrometers of tissue with associated thermal effects 5

Clinical Optimization

• When combined with platelet-rich plasma (PRP), CO2 laser treatment shows enhanced histological improvement including increased epidermal thickness and normalized orientation of dermal collagen fibers 4
• The thermal injury creates microthermal wounding that, when augmented with growth factors from PRP, accelerates the collagen remodeling process 4
• Limiting the number of CO2 passes or ending treatment with erbium:YAG laser can reduce excessive thermal necrosis while still achieving adequate collagen stimulation 5