A method for transdermally treating selected tissue and/or for facilitating the release and/or differentiation of stem cells, including exposing the selected tissue to laser light having a wavelength between approximately 600 and 1400 nm, and maintaining such exposure of the selected tissue or bone to the laser light for a period of time sufficient to deliver a laser light dosage of at least 3 Joules/cm2 per treatment and maintaining such exposure for a period of time sufficient to deliver a laser light dosage of at least 1000 Joules per treatment within a 24 hour period of time. The method also includes upcollimating the laser light such that the laser delivers to the selected tissue a substantially coherent beam of laser light having a cross-sectional area of at least 5 cm2, and, further, delivering the laser light to a depth of at least 5 mm in the selected tissue.