Drug abuser patients (n=104), age ranging from 19 to 42 years, were randomly recruited to investigate the serum levels of trace elements (Cu, Zn, Fe, and Mg), malondialdehyde (MDA), and immunoglobulin (IgG, IgA, and IgM) before and after clinical intervention. Control group also included 104 healthy individuals. Blood samples were analyzed for determining trace elements, MDA, and immunoglobulin using atomic absorption spectroscopy, Ultraviolet-Visible (UV-VIS) spectroscopy, and turbidimetry method, respectively. For serum level of Zn and Fe, the differences between the groups (before intervention, after intervention, and control) were not significant (p>0.05). However, significant differences were found in serum copper levels between control group, drug abuser patients, and before and after intervention (p<0.05). The concentration of Mg was found to be significantly higher (p=0.007) in drug abuser patients than the controls, and after intervention, the level was restored to control value. A displacement of elemental homeostasis was observed in drug abuser patients compared to control, and it was improved after intervention. An increase in serum concentration of MDA was found in drug abuser patients compared to control subjects (p>0.05) but was not statistically significant. After intervention, the concentration was restored to control value (p>0.05). The serum concentrations of IgA and IgM were found to be significantly higher (p<0.05) in drug abuser patients before intervention than the controls, and the level tended to be restored to control level after clinical intervention. Serum IgG level was found to be lower in drug abuser patients compared to controls and further declined significantly (p<0.05) after intervention. These findings may suggest a possible imbalance in the levels of micronutrients, antioxidants, and immunoglobulin in drug abuser patients, which tend to be restored to control values after detoxification.