Unregulated Gains: A Comprehensive Review of Illicit And Amateur use of Unconventional Performance- Enhancing Drugs—Pharmacology, Classification, and Health Risks

Background: The use of image and performance-enhancing drugs (IPEDs), including anabolic androgenic steroids (AAS), selective androgen receptor modulators (SARMs) and advanced synthetic agents has spread beyond professional sports into recreational bodybuilding and fitness subcultures. Despite their continued use, serious gaps remain in our knowledge and understanding of them, including the various health harms. IPEDs are often obtained through unregulated channels and used without medical oversight, raising serious concerns about safety and misuse. Their growing popularity further compounds these concerns, with the broader public impact of IPED use poorly understood. Objective: Responding to this apparent gap in understanding, this review outlines lesser-known IPEDs for muscle enhance-ment, their mechanisms, and associated health risks. Methodology: A non-systematic review of the past 40 years of literature (PubMed, Scielo, Google Scholar) examined SARMs, designer steroids, and other IPEDs, grouping them by pharmacology, toxicity, and health risks. Twenty-four dis-tinct compounds were explicitly documented and reviewed. Results: Various IPEDs were identified and were categorized into four main groups based on health risk and chemical structure: (1) SARMs (e.g., S-23), (2) designer steroids (e.g., superdrol), (3) ultra-potent designer steroids (e.g., fluoxyme-sterone), and (4) high-risk substances (e.g., 2,4-Dinitrophe-nol). IPEDs promise muscle and performance gains but car-ry risks of organ damage, hormonal disruption, and psychiatric effects, made worse by unregulated supply. Conclusion: This study underscores the importance of up-to-date research, to foster awareness and understanding of potential health harms, of lesser known IPEDs. As different IPEDs continue to emerge through underground markets, where unregulated use and misinformation pose major health risks, this study holds great importance, providing much needed insight to help support and protect this population.