The present invention is a portable non-invasive apparatus, system, and method for performing light therapy or photobiomodulation upon the brain tissues through the nostrils of a living mammalian subject for the medical purpose of stimulating the brain in-vivo. In marked difference to conventionally known therapeutic procedures, the present invention utilizes the intranasal pathway as the point of anatomic access and follows established principles for the conceptual approach that irradiation of the brain tissue with low level light energy of certain fixed parameters would achieve major therapeutic effects in-vivo. In this manner, the present invention utilizes light energy of specified wavelengths, coherency, and pulsed mode to achieve therapeutic outcomes.
