Abstract
Background: Use of anabolic androgenic steroids (AAS) has been associated with adverse physical and psychiatric effects and it is known as rising problem among youth people. This study was conducted to evaluate anabolic steroids preventative intervention efficiency among gym users in Iran and theory of planned behaviour was applied as theoretical framework. Methods: Overall, 120 male gym users participated in this study as intervention and control group. This was a longitudinal randomized pretest - posttest series control group design panel study to implement a behaviour modification based intervention to prevent AAS use. Cross -tabulation and t-test by using SPSS statistical package, version 13 was used for the statistical analysis. Results: It was found significant improvements in average response for knowledge about side effects of AAS (P<0.001), attitude toward, and intention not to use AAS. Additionally after intervention, the rate of AAS and supplements use was decreased among intervention group. Conclusion: Comprehensive implementation against AAS abuse among gym users and adolescences would be effective to improve adolescents’ healthy behaviors and intend them not to use AAS.