Cold Laser Therapy

(Low Level Laser Therapy)



Cold lasers are FDA cleared for pain reduction, inflammation reduction and increased blood flow in humans. These are the only benefits that cold laser manufacturers and cold laser practitioners can legally claim. Although thousands of studies have been done showing addition benefits from cold laser therapy, they are all considered off-label by the FDA and cannot be used to advertise cold lasers or cold laser therapy. Cold lasers have been proven to be safe in over 3000 research papers but it is up to users to do their own research if they are looking for anything more than the 3 approved applications. Therapeutic cold lasers may be used on pets and horses without any restrictions. The FDA only restricts the sale of low level or cold lasers for treatment on humans.


There are 5 main factors that control the efficacy of cold lasers:


1. Wavelength. This is the wavelength of the light that is directed into the body to promote a change. Wavelength is the key to depth of penetration. That is why most popular lasers operate in the 800nm to 940nm wavelength range. This wavelength is in the center of the therapeutic window so it reacts less with the water (below 700nm) or blood (above 900nm) in your body and more with the tissue, bone and ligaments. If you are look for deep penetration, you want to buy something that operates in the 800 to 940nm range. Cold laser become less efficient above this range so some class 4 lasers with massive output (10 watts or greater) require a high level of power to produce the same effect as a smaller laser that operates within the therapeutic window.


2. Pulsing Frequency: Some systems turn on and off the laser at different pulsing frequencies to provide addition benefits. Although the majority of the benefit in cold laser therapy is from accumulating light energy (measured in Joules), there is also some addition benefit gained by turning on and off (pulsing) the laser beam. Some manufacturers use a sweeping pulse where the frequency is changing to hopefully hit the best pulsing frequency at least some of the time. There is no consensus on pulsing so some manufacturer system are pulse and sweep only and other systems are continuous only. Selecting a unit with pulsing, continuous wave or both is mostly a matter of preference.


3. Power: Power is the most important element when if comes to efficacy. There is an optimum power density for the best results and more powerful unit can reach that optimum faster than lower power units. Too little or too much power can still help but may produce inconsistent results. For a majority of the professional system, power is 60 to 70% of the solution. The goal of most high end systems is to get the optimum level of energy density (around 50 joules per square inch) to the damage area and put some energy into the surrounding area. Higher power levels do this faster. They do now push the energy any deeper but at any given depth, more power will reach the target density faster. Some older system and low end system are so low power that they never reach the optimum but the still can produce positive effects.


4. Treatment Area: Lasers can be used for broad coverage of damaged tissue but they can also be used for trigger point therapy by acupuncturist or trained practitioners. If you will be working with small treatment areas like a small pet, human ears or you will be doing laser-puncture (acupuncture without the needles), you will need to buy a unit with a focused beam or a laser that has an adapter to focus the beam. For the majority of the common pain application, the larger the diameter of the emitter, the better the results.


5. Protocols: Protocols tell users how to setup the laser to treat each condition. Laser can be used to treat human, pet s and horses. Some lasers are based on “cookbook” style protocol manuals and other are based on guidelines that are commonly used in professional practices.

Laser Classes and Limitations


Lasers are grouped into classes based on their ability to do damage to the eye. 

  • Class 1 and 2 lasers are the safest and they can be purchased for home use on humans.

  • Class 3 lasers range from 50 to 500mW per beam (laser may have multiple beams) and can be purchased for home use on a human with a recommendation from a health care professional.

  • Class 4 lasers are the most dangerous to the eye and they some higher power class 4 laser do have a risk of skin damage (above about 15 watts). Class 4 systems are only sold to professional for use on human. Anyone can buy any class laser for use on pets and horses but many class 4 manufacturers limit the sale of their product to non-professionals.