Photobiomodulation Therapy (PBMT) is a novel modality using irradiation with light-power-intensity light. Recently, applications of PBMT have been broadened to thousands of people around the world for various medical conditions and dermatological conditions. Normally, light sources used in PBMT are non-coherent light (Light Emitting Diodes-LED) or coherent light (lasers). LED-light-source-based devices offer several advantages compared with laser devices, including ease of home use, simultaneous irradiation of a large area of tissue, availability for wearable devices, much lower price, and enhanced safety. Thus, various LED-based devices for dermatological and cosmetics applications have been designed and developed and sold on the global market. However, LED therapy still confronts many challenges that limit its applications and cause human-health concerns. Herein, we provide a critical review of the various applications of LED therapy in the fields of dermatology and beauty: skin rejuvenation, acne treatment, scarring prevention, hair restoration, fat reduction and cellulite treatment, and tooth whitening. Also, the challenges to the development of LED therapy and its action mechanisms are identified and discussed in detail. Additionally, future perspectives for development of LED light phototherapy are pointed.

光生物调节疗法（PBMT）是一种使用光强度光照射的新型方法。最近，PBMT的应用已经扩展到世界各地成千上万的各种医学状况和皮肤病学状况的人们。通常，PBMT中使用的光源是非相干光（发光二极管-LED）或相干光（激光）。与激光设备相比，基于LED光源的设备具有多个优势，包括易于居家使用，同时照射大面积组织，可穿戴设备的可用性，低得多的价格以及增强的安全性。因此，已经设计和开发了用于皮肤病学和化妆品应用的各种基于LED的设备，并在全球市场上出售。然而，LED疗法仍然面临许多挑战，限制了其应用并引起人类健康问题。在此，我们对LED疗法在皮肤科和美容领域的各种应用进行了严格的综述：嫩肤，痤疮治疗，预防疤痕，毛发修复，脂肪减少和脂肪团治疗以及牙齿美白。此外，LED疗法及其作用机制的发展面临的挑战也得到了确定和详细讨论。另外，指出了发展LED光疗法的未来前景。LED疗法及其作用机制的发展面临的挑战已得到确定和详细讨论。另外，指出了发展LED光疗法的未来前景。LED疗法及其作用机制的发展面临的挑战已得到确定和详细讨论。另外，指出了发展LED光疗法的未来前景。