What is Red Light Therapy?

Red light therapy is the use of a light emitting diode (LED) with a frequency of 660nm. This wavelength penetrates tissue to about 10mm which makes it effective for treating problems close to the surface for example cuts, scars, trigger and acupuncture points, it is particularly effective at treating infections.

Red light therapy is based on the fact that by applying light to an area the photons in the light increase the energy available to the tissue. This energy is absorbed and used to repair the tissue, reduce pain and/or restore normality to an otherwise impaired biological process. The amount of energy applied depends on the wavelength of the light, the greater the wavelength the more photons and therefore energy is available. The mitochondria within the body’s cells absorb this energy and convert it into adenosine triphosphate (ATP) which it uses to power its various functions.

The application of red light has been shown to produce the following :

  • Relaxation of muscles, reduced nerve excitability and stimulation of nerve transmission
  • Reduction of scar tissue and stimulation of wound healing
  • Increased lymphatic system activity and reduction in edema and discomfort associated with swelling
  • Stimulation of acupuncture points and immune response
  • Stimulation of production of collagen—the most important component of wound healing
  • Reduction of inflammation and swelling in chronic conditions of arthritis, bursitis, and tendonitis
  • Stimulation of tissue granulation and connective tissue formation - an important process in the healing of wounds, ulcers and inflamed tissues
  • Increased blood capillary circulation and vascular activity by promoting improvement in the metabolism of nitric oxide. This facilitates improved regulation of vasodilation and results in the formation of new capillaries - this in turn provides additional oxygen and nutrients to accelerate natural tissue healing processes and eventually evokes a cascade of beneficial biochemical processes.
  • Stimulation of the adrenals— which facilitate long term pain relief and resilience to stress
  • Increased production of endorphins and encephalin from the brain - promoting pain reduction and mood elevation
  • Stimulation of (ATP) sysnthesis—an immediate energy source for muscle contraction and essential in the metabolism of all cellular processes and sustaining living systems
  • Increased RNA/DNA synthesis - this stimulates cellular reproduction and facilitates accelerated replacement of damaged cells
  • Increased phagocytosis - the body’s natural process to scavenge dead and degenerated cells it is important to the infection control process required for healing
  • Stimulation of fibroblastic activity - promoting repair of connective tissue and formation of collagen fibers


The physical response of the wound healing visibly demonstrates the biological effects the red light has as a healing modality. Whereas the stimulation of acupoints demonstrates the chemical responses the body has to red light stimulation, the results of which are seen, not only in the improvement in the horses well being, but also during a session with the physical releases shown (yawning, licking chewing etc). In the same way as the cells know when they have had enough stimulation by the red light, the horses appear to know when they have had enough stimulation too. This is shown when they move away from stimulation of an acupoint or wound healing.

Red light therapy is a versatile modality which can be used in many situations. It is a stand alone therapy but also works very well with both massage and particularly myofascial release. Stimulation of relevant acupoints prior to using myofascial techniques has in my experience produced very positive responses both in the way the horse behaves during the session and the results achieved and maintained following the session. Its direct use on injuries is remarkable, I have used it on several wounds and soft tissue injuries, these have healed much faster than when the light was not used.

Background information

In 1965 the Russians and Czechs were trying to standardise light therapy and experimented with different light colours. They discovered that a single frequency laser light can stimulate DNA synthesis in a damaged call. About ten years later researchers from the University of Chicago discovered that the average wavelength of light within the body’s tissue is between 600 and 720 nm. The frequency of 660nm falls in the middle of this spectrum, therefore is best for healing as it is closest to the resonant frequency of the cell tissue, haemoglobin also absorbs 660nm the best.

Further research by Tiina Karu looked at laser versus LED’s. She found that laser emits a single frequency beam of light which the cell is unable to switch off; therefore the cell is not in control of the amount of light stimulation it receives. This could have a negative effect on the cell as with laser light there is a point when the lights stops being beneficial and starts deterioration within the cell. She found that as LED’s emitted a more diffuse light, the cells were able to shut off when they no longer required stimulation; therefore the cell was in control. There can be no overuse of LED’s. (http://www.elixa.com/light/healing.htm)