The purpose of this 8-week open-label study is to assess the tolerability, safety, and efficacy of Transcranial LED Therapy in patients with Autism Spectrum Disorder (ASD). The investigators propose to enroll up to 30 subjects of both genders ages 9-59 years with intact intellectual functions who meet the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for Autism Spectrum Disorder (ASD).

Subjects may be included in the study only if they meet all of the following criteria:

• Male or female participants between 9 and 59 years of age (inclusive)
• Fulfills DSM-5 diagnostic criteria for autism spectrum disorder as established by the clinical diagnostic interview.
• Participants with at least moderately severity of ASD symptoms as demonstrated by SRS raw score ≥ 85 and CGI-ASD severity score ≥ 4
• Participants must understand the nature of the study. If the participant is under the age of 18, the participant's parent/guardian must sign an IRB-approved informed consent form before initiation of any study procedures. Participants ages 18-59 must sign an IRB-approved informed consent form before the initiation of any study procedures.
• Participants must have a level of understanding sufficient to communicate with the investigator and study coordinator, and to cooperate with all tests and examinations required by the protocol.
• Participant experiencing a major psychiatric disorder will be allowed to participate in the study provided they do not meet any exclusionary criteria.
• Women of child-bearing potential must use a double-barrier method for birth control (e.g. condoms with spermicide) if sexually active.
• The subject is willing to participate in this study.

Subjects will be excluded from the study for any of the following reasons:

• Impaired intellectual capacity (clinically determined)
• Participant is unable to communicate due to delay in, or total lack of, spoken language development (grossly impaired language skills)
• Clinically unstable psychiatric conditions or judged to be at serious safety risk to self (suicidal risk) or others (within past 30 days).
• Subjects currently (within past 30 days) experiencing significant symptoms of major psychiatric disorders as clinically determined.
• Subjects with an unstable medical condition (that requires clinical attention).
• Active suicidal or homicidal ideation, as determined by clinical screening.
• The subject has a significant skin condition at the procedure sites (i.e., hemangioma, scleroderma, psoriasis, rash, open wound or tattoo).
• The subject has an implant of any kind in the head (e.g. stent, clipped aneurysm, embolised AVM, implantable shunt - Hakim valve).
• Any use of light-activated drugs (photodynamic therapy) within 14 days prior to study enrollment (in US: Visudine (verteporfin) - for age related macular degeneration; Aminolevulinic Acid- for actinic keratoses; Photofrin (porfimer sodium) - for esophageal cancer, non-small cell lung cancer; Levulan Kerastick (aminolevulinic acid HCl) - for actinic keratosis; 5-aminolevulinic acid (ALA)- for non-melanoma skin cancer)
• Current treatment with a psychotropic medication on a dose that has not been stable for at least 4 weeks prior to initiating study treatment.
• Investigator and his/her immediate family, defined as the investigator's spouse, parent, child, grandparent, or grandchild.

Zero participants ages 9-17 enrolled

8 weeks (from baseline to end of study)