Light-emitting diode (LED) therapy employs narrow-spectrum, incoherent light for photobiomodulation in dermatology, offering advantages of safety, non-invasiveness, and ease of use. This review examines its mechanisms and applications in skin aesthetics, focusing on specific wavelengths. A comprehensive literature review assessed the mechanisms, clinical uses, and outcomes of LED therapy at key wavelengths: blue (400-470 nm), yellow (570-590 nm), red (630-760 nm), and near-infrared (NIR, 760-1200 nm). LED light interacts with specific skin photoreceptors (including opsins, mitochondrial cytochrome C, cryptochromes), regulating mitochondrial function and immune responses. This interaction induces beneficial cellular changes such as proliferation, differentiation, enhanced collagen synthesis, and modulation of inflammation. Key clinical findings include: Blue light effectively targets acne vulgaris and aids skin barrier repair primarily through antibacterial effects. Yellow light demonstrates efficacy in reducing melasma and photoaging by suppressing melanogenesis. Red light, with deeper penetration, promotes scar healing, hair growth, and skin rejuvenation. Near-infrared light shows promise in managing pigmentary disorders, skin aging, and accelerating wound healing. Furthermore, combining different LED wavelengths enhances therapeutic outcomes for conditions like acne, photoaging, and wound repair. LED-mediated photodynamic therapy (PDT) proves effective for acne and photoaging, offering improved safety and practicality over conventional coherent light sources. LED therapy represents a promising, non-invasive, and safe modality within dermatology and aesthetic medicine. Ongoing research is paving the way for increasingly personalized and targeted light treatments tailored to individual skin conditions, solidifying its role in the aesthetic armamentarium.
Guo et al. (Sat,) studied this question.