Monthly injectable treatments for opioid addiction face significant real-world challenges that controlled trials often miss. This Ukrainian experience reveals how implementation barriers can undermine even promising pharmaceutical innovations designed to improve treatment adherence. The 12-month trial tracked 181 patients across 10 Ukrainian cities who switched from daily sublingual buprenorphine tablets to monthly CAM2038 injections. Despite theoretical advantages of extended-release formulations, uptake proved disappointing - only 273 of approximately 2,300 eligible patients agreed to switch. Treatment persistence showed concerning patterns: while 80% received at least two injections, retention dropped sharply over time. By the 13th month, just 44% remained on the monthly injection protocol, with 30% switching back to daily tablets and 26% discontinuing opioid treatment entirely. The study identified distinct risk factors for each dropout pathway, suggesting different underlying causes. Dose optimization emerged as a critical factor - 74% of patients starting on the lowest 64mg dose required increases, and 13% needed supplemental daily medication alongside their monthly injections. This Ukrainian data contrasts sharply with more optimistic results from controlled trials in high-income countries, highlighting how socioeconomic context, healthcare infrastructure, and patient preferences shape treatment outcomes. The findings underscore a broader challenge in addiction medicine: translating controlled research into effective real-world interventions. For clinicians considering extended-release formulations, this study suggests careful patient selection and robust support systems are essential for success, particularly in resource-constrained settings where treatment disruption carries higher stakes.