You might have seen those robot-looking red light masks being sold for skincare purposes. 

You might have thought — looks technological, but does it work?

It's not just red light. There are a spectrum of health claims from infrared to ultraviolet.

Norman and Tegan go through the rainbow to assess where there's evidence, and where there's not. 

References:

• Near Infrared Photoimmunotherapy: A Review of Recent Progress and Their Target Molecules for Cancer Therapy
• Effect of NASA Light-Emitting Diode Irradiation on Wound Healing
• Visible Red Light Emitting Diode Photobiomodulation for Skin Fibrosis: Key Molecular Pathways
• Utilization of light-emitting diodes for skin therapy: Systematic review and meta-analysis
• Photodynamic Therapy Using HMME for Port-Wine Stains: Clinical Effectiveness and Sonographic Appearance
• Effect of Blue Light on Acne Vulgaris: A Systematic Review
• The efficacy of violet light in the treatment of acne
• Featured review: What are the benefits and risks of light therapy for treating atopic eczema?
• Light therapy for preventing seasonal affective disorder