BACKGROUND: Opioid dependence, is one of the world's most critical health problems. Deaddicta is a herbal product considered an effective treatment for opioid addiction. Deaddicta's efficacy in the maintenance treatment of patients with opioid use disorder has recently been demonstrated through a double-blind randomized controlled trial (RCT). This study aimed to evaluate the permanence of Deaddicta's efficacy six months after the end of the maintenance treatment for opioid dependence. METHODS: This study was performed following the previous RCT on the maintenance treatment of opioid addicts. Out of 41 participants who completed the study for three months in the previous research, 15 from the intervention group (Deaddicta capsules, 1500 mg/day) returned for follow-up. They all previously fulfilled the DSM-IV criteria for addiction, were aged 18 to 65, and had discontinued Deaddicta for six months. The outcome measures included addiction severity, depression and anxiety levels, and craving score. The scores of each parameter were compared in three phases: before intervention; after three months of intervention; and six months after the end of the study. RESULTS: Depression, anxiety, and craving scores decreased six months after the end of the previous study. This decrease was significant in the craving score ( = 0.011). No significant increase was observed in the frequency of use. The regression analysis showed a negative relationship between craving and the progression of phases. CONCLUSION: The Deaddicta product may have desirable and effective properties in decreasing temptation and, as a result, the maintenance treatment of opioid dependence.