Occasionally I receive questions about the effectiveness using low level laser vs normal light emitting diode (LED) for intranasal blood irradiation light therapy.

There are several papers that suggest that low level lasers are more effective than LEDs. Several websites publish these to support their products. These studies are based on transcutaneous/transdermal (applied to the skin) applications, not on intravenous or intranasal blood irradiation, which is our case.

Basically, the cells and the body systems respond to the combination of the wavelength of the light and the energy dosage. The coherent light in lasers can have more concentrated energy than the normal non-coherent light in LEDs, even though most commercially available semi-conductor low level laser diodes have a built-in divergence of about 57 degrees. The question is whether low level lasers are more effective for therapeutic purposes than LED.

Respected scientist in photobiology, Professor Kendric Smith of the Stanford University School of Medicine have this to say, “All too often the laser phototherapy literature is written as if a laser is magical. Lasers .. emitted radiation follows
(except for coherence) all of the same laws of physics and chemistry that
the same wavelength of radiation from a conventional (non-coherent) light
source follows. [1]

In addition, leading scientist in low level laser therapy, Tiina Karu says, “No significant difference was found for growth stimulation regardless of whether the light used was generated by a laser or from light of the same wavelength from a filtered incandescent lamp. [2]

In a landmark NASA-sponsored study published in 2001, scientists have foundĀ  LED therapy to be effective for faster wound healing and significantly more pain reduction. [3]

When using LED instead of laser diodes, we compensate for the lost coherency by increasing the energy dosage per area. In the end we will see the same effectiveness from our own evidence.

In the case of intranasal light therapy applications, because we are in the realm of well under 10 mW in energy output and dealing with much thinner dermal layers, the increase is so small that the user would not feel that difference. The membrane inside the nasal cavity is thin enough that a LED diode with some recalibration will achieve the same result as the laser diode.

The bottom line is that our LED device (Qi-Light) has the same effective outcomes as the laser device (RadiantLife LT) but the LED device is a bigger drain on the battery (by roughly as much as 30%) because of the additional energy requirements.


1. Smith, K.C. (2005), Laser (and LED) Therapy Is Phototherapy, Phtotomedicine and Laser Surgery, 23, 78-80.

2. Karu, T. (1989). Photobiology of low-power laser effects. Health Physics,
56, 691-704.

3. Whelan, H.T. et al (2001). Effect of NASA Light-Emitting Diode Irradiation
on Wound Healing. Journal of Clinical Laser Medicine & Surgery. 19 (6).