Mechanism of Action
Creation of Micro-Injuries:
The procedure involves rolling or stamping the skin with fine needles, producing tiny punctures (microchannels) that reach the epidermis and, depending on needle length, the dermis 1,3,5,6. These micro-injuries are superficial and controlled, designed to trigger the skin’s natural healing process without causing scarring or prolonged inflammation 3,5,6.
Wound Healing Cascade:
The body perceives these micro-injuries as damage, initiating a wound healing response. This involves:
- Release of Growth Factors: Platelet-derived growth factor (PGF), transforming growth factor (TGF-α and TGF-β), connective tissue growth factor, and fibroblast growth factor (FGF) are released at the site of injury 5.
- Activation of Fibroblasts: These cells migrate to the injury site, proliferate, and begin synthesizing new collagen and elastin fibers—key proteins responsible for skin strength, elasticity, and youthful appearance 1,3,5.
- Neovascularization: The process also encourages the formation of new blood vessels (angiogenesis), which improves skin nourishment and health 5,7.
Collagen Induction and Skin Remodeling:
The primary therapeutic benefit is collagen induction therapy—the micro-injuries stimulate the production and reorganization of collagen and elastin, leading to smoother, firmer, and more resilient skin over time 1,3,8.
Enhanced Absorption of Topical Agents:
The microchannels temporarily increase skin permeability, allowing for better absorption of topical serums and medications applied immediately after treatment 4,8.
Scientific Theories
There are two main hypotheses explaining the effectiveness of microneedling:
- Classical Wound Healing:
Micro-injuries trigger the body’s standard wound healing phases—hemostasis, inflammation, proliferation, and remodeling—without causing significant scarring or fibrosis due to the controlled nature of the injury 6. - Bioelectrical Stimulation:
The needle penetration alters the skin’s electrical potential, which may stimulate cellular activity, DNA synthesis, and growth factor production, further enhancing tissue regeneration 5,6.
Depth and Frequency
- Needle Depth:
The depth of penetration is tailored to the skin concern. For collagen induction, 1–1.5 mm is typical, with deeper treatments reserved for scars or stretch marks 4,7. - Treatment Frequency:
Multiple sessions, spaced several weeks apart, are often recommended for optimal collagen production and skin improvement 4.
Summary:
Microneedling works by harnessing the body’s natural healing mechanisms through controlled micro-injury, leading to increased collagen and elastin production, improved skin texture, and enhanced absorption of skincare products. This makes it an effective, versatile treatment for scars, wrinkles, and overall skin rejuvenation 1,3,5,6.
