Find out more about the science behind red light therapy.

How does red light therapy work?

RLT involves exposing the body to low-wavelength red light :

  • Red light: part of the visible spectrum of light with a wavelength between 610 and 760 nm (nanometers), these lights can penetrate deep into tissues (up to 2cm)

  • Near-infrared Light: with a longer wavelength between 760 nm and 1400 nm, infrared is no longer visible to the naked eye. These lights can penetrate much deeper into the body reaching muscles and organs.

This powerful combination of lights penetrate deep into the skin, where mitochondria in the skin cells can absorb these light particles. This can help the cells produce more adenosine triphosphate (ATP), the energy source for all cells. With more energy, cells can function more efficiently, rejuvenate themselves, and repair damage.

Where does red light therapy come from?

In 1993, the National Aeronautics and Space Administration (NASA) began experimenting with red light therapy for plant growth in space and then to help heal wounds in astronauts. Later in October 1995, sources of red light—part of the visible spectrum of light—made their space shuttle flight debut on the second U.S. Microgravity Laboratory Spacelab mission (STS-73, Columbia) as part of experiments in plant growth.

Nowadays red light therapy is already widely medically accepted in its use in photodynamic therapy.

Now, RLT is being investigated (or already in use) for treating a wide array of health conditions. What’s confusing — and controversial — is the effectiveness of the treatment for the purposes it’s being promoted.

Decrease sign of aging & Collagen

The skin is largely made of collagen, a protein that prevents it from sagging and keeps it looking and feeling plump. While collagen is naturally produced by the body, sun exposure, smoking, pollution exposure and aging decrease production causing skin to lose elasticity and appear to sag and wrinkle. A 2014 study found full-body exposure to red light over the course of 30, twice-a-week sessions increased collagen density on participants’ faces and caused visible improvements in wrinkles and skin roughness.

How effective is RLT for wound healing?

As research in the journal AIMS Biophysics notes, many of the conditions that RLT treats have their roots in inflammation. Although the exact reason is not yet clear, RLT has significant anti-inflammatory effects and increase fibroblast production, which makes collagen.

What factors improve RLT?

  • Irradiance = amount of energy a specific part of your body receives over a set period. A higher irradiance can result in better results for less time. The most used format to measure irradiance is mW/cm2 (milliwatts per square centimetres). However, just stating the irradiance measurement means nothing if the distance is not provided. Some RLT devices have a high mW/cm2 reading on the surface of the device, and not on the object exposed to it.

  • Frequency: The range of frequency used in typical RLT devices is from 610 nm (a deep red, penerates the skin and acts on mitochondria) to 950 nm (near-infrared, penetrates deeper into tissue)

  • Treatment coverage area: it’s alway a better idea to use a RLT device with the maximum coverage as larger devices emit more light energy and better performance than smaller units like at-home devices.

RLT vs laser vs pulsed light?

RLT is different from laser or intense pulsed light (IPL) therapies because it doesn’t cause damage to the skin surface. Laser and pulsed light therapies work by causing controlled damage to the outer layer of the skin, which then induces tissue repair. RLT bypasses this harsh step by directly stimulating regeneration of the skin. The red light is natural and can penetrate deep into the skin, where the cells can absorb and use it.