Obesity and overweight is a global health crisis and novel methods of treatment are needed to address it. Low-level laser therapy (LLLT) is a currently available non-invasive procedure for lysing excess fat, but there is a lack of consensus exists on LLLT frequency and limited research from studies of LLLT. The purpose of this pilot study is to compare the effect of three of the most common LLLT frequencies on weight, waist circumference, body fat percentage, and quality of life. Sixty overweight (body mass index (BMI) 25-29.9 kg/m 2 ) adult participants were randomized to 12 LLLT treatments: (1) three times weekly for 4 weeks, (2) twice weekly for 6 weeks, or (3) once weekly for 12 weeks. All participants attended an in-person visit at baseline and at weeks 4, 6, 12, and 26. Participants were recruited September 30, 2016 through to August 27, 2017. The majority of the 60 participants were female (90%) with an average age of 43.7 years (± 9.2 years). Most participants (98%) completed 10 or more of the 12 LLLT treatments. When comparing across treatment groups, the greatest reductions from baseline were observed in those assigned to twice weekly for 6 weeks in weight (1 ± 1.7 (±SD) kg by week 6), waist circumference (− 2.0 ± 3.2 in. by week 6 and − 1.5 ± 3.2 in. by week 26), body mass index (− 0.4 ± 0.6 kg/m 2 ), and body fat mass (− 1.1 ± 1.6 kg). This group also had the most significant improvement from baseline in quality of life (+ 0.5 ± 0.8 by week 6), body satisfaction (+ 0.2 ± 0.4 by week 6 and week 26), and body appreciation (+ 0.2 ± 0.3 by week 6 and + 0.3 ± 0.3 by week 26). LLLT twice weekly for 6 weeks could be proposed as the optimal frequency and duration for the management of body weight. Trial registration: https://clinicaltrials.gov/ ct2/show/NCT02877004. Registered August 24, 2016.