Nandrolone decanoate, a synthetic form of the testosterone hormone, is misused by some bodybuilders and adolescents to gain muscle mass. We investigated its effect on the prostate during postpubertal age and evaluated the reversibility of these effects after a period of cessation. Thirty albino rats were utilized and categorized into three distinct groups: Control group, a treated group that received nandrolone decanoate weekly by intramuscular injection with 10 mg/kg for 4 weeks while recovery group received nandrolone, similar to the treated group, followed by an additional recovery period of 4 weeks. In the treated group, there were significant elevation in IL-1β, IL-18, IL-6, TNF-α, COX2, MDA, BAX, PSA, and miRNA-155 expression and decreased in SOD, GST, bcl2, and testosterone hormone compared to the control group. Prostatic acini showed marked epithelial stratification, weak PAS positive reactions, excess collagen depositions, and negative ARs nuclear immunoexpression. Ultrastructrally, cytoplasm contained vacuoles and dilated cisterna of RER. In the recovery group, insignificant differences were observed between the recovery and control groups, and most of the acini appeared normal except for minimal changes. Nandrolone-induced structural and functional impairment of the prostate at cellular and molecular basis and cessation of it in the recovery group ameliorated the impairment.