Principles of LED Phototherapy, Red vs Blue Light
LED phototherapy is a non-invasive treatment that uses specific light wavelengths to help activate cells. The most widely used wavelengths are red light and blue light (Cleveland Clinic, NIH).
Red light (approx. 630-660nm) penetrates deep into the dermal layer. It stimulates mitochondria to increase ATP (cellular energy) production and promotes collagen and elastin synthesis, helping improve fine lines and elasticity. In contrast, blue light (approx. 415nm) acts on the surface layer to eliminate 'Cutibacterium acnes' (C. acnes), offering powerful antibacterial effects against acne (American Academy of Dermatology).
Modern home devices often combine these wavelengths to address multiple skin concerns. For safety, always choose FDA-cleared devices and use eye protection to prevent retinal damage during use.