Despite a lack of consensus over its ideal use, specific test and protocols for LLLT suggest it is effective in relieving short-term pain for rheumatoid arthritis,^[1] osteoarthritis,^[5] acute and chronic neck pain,^[6] tendinopathy,^[3][7] and possibly chronic joint disorders.^[4] The evidence for LLLT being useful in the treatment of low back pain,^[8][9] dentistry^[10][11] and wound healingis equivocal.^[12]

In 1967 a few years after the first working laser was invented, Endre Mester in Semmelweis University in Budapest, Hungary experimented with the effects of lasers on skin cancer. While applying lasers to the backs of shaven mice, he noticed that the shaved hair grew back more quickly on the treated group than the untreated group.^[13]

LLLT has primarily been shown useful in the short-term treatment of acute pain caused by rheumatoid arthritis,^[1] osteoarthritis,^[5] tendinopathy,^[3][7] and possibly chronic joint disorders.^[4]LLLT has also been useful in the treatment of both acute and chronic neck pain.^[6] A Cochrane Library review concluded that low level laser therapy (LLLT) has insufficient evidence for treatment of nonspecific low back pain,^[8] a finding echoed in a later review of treatments for chronic low back pain.^[9] Though it has been suggested for decades that LLLT could be useful in speeding wound healing, the appropriate parameters (dose, type of laser, materials, wavelength, etc.) have not been identified.^[12] Similarly, the use of lasers to treat chronic periodontitis^[10] and to speed healing of infections around dental implants^[11] is suggested, but there is insufficient evidence to indicate a use superior to traditional practices.^[14]

Stephen Barrett, writing for Quackwatch, concluded there was evidence to support LLLT use for temporary pain relief, but "there's no reason to believe that they will influence the course of any ailment or are more effective than other forms of heat delivery."^[15]