Introduction: Substance use health challenges are reported by a large number of Canadians and are responsible for substantial personal suffering and societal costs. Digital and peer support interventions have been recommended to address barriers to care and support long-term health. This study presents preliminary findings from an evaluation of an online cognitive behavioural therapy (Breaking Free Online [BFO]), peer support, or both for adults with substance use disorder (SUD). The primary objective was to assess changes in health outcomes at week 8 across all three treatment groups. The secondary objective was to examine how patients gave meaning to their experience of the supports. Methods: Participants were assigned to one of three groups: (1) BFO alone, (2) BFO + individual peer support, or (3) clinical monitoring (CM) with group peer support. SUD diagnoses were confirmed using the Structured Clinical Interview for DSM-5. Participants completed self-report measures, including the Alcohol Use Disorder Identification Test (AUDIT), Drug Use Disorders Identification Test (DUDIT), Severity of Dependence Scale (SDS), Patient Health Questionnaire (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), World Health Organization Disability Assessment Schedule 2.0 (WHODAS) and World Health Organization Quality of Life – BREF (WHOQOL). Qualitative interviews were also conducted post-treatment. Results: A total of 198 participants have been randomized to treatment, primarily with alcohol, cannabis, or stimulant use disorder. Mixed effects models revealed significant reductions in AUDIT, DUDIT, and SDS scores at week 8. Mixed effects models also revealed significant improvements in disability at week 8, indicating reduced functional impairment. Similarly, mixed effects models revealed significant improvements across all quality of life domains (physical, psychological, environmental, social) at week 8. Thematic analysis revealed several barriers and facilitators to access and benefit from services and supports. Participants highlighted the accessibility, convenience, and relevance of all supports, but particularly the value of peer support to provide encouragement, accountability, and guidance in progressing towards individual substance use health goals. Participants also highlighted specific features of each intervention, such as progress reports of their substance use and mental health, alongside risk alert features, in facilitating their use of the intervention. Conclusions: Findings suggest self-reported reductions in substance use health challenges, including overall SUD severity across all types of services and supports. These early findings suggest that online support shows promise in improving substance use and functional outcomes. Moreover, qualitative interviews revealed strategies to optimally deliver support during the care journey to facilitate a patient-centred approach.