The article is a review of how labs look for new performance‑enhancing substances, including the peptide AOD‑9604, in athletes' blood or urine. It talks about the lab techniques needed to spot these tiny molecules, but it doesn't give any advice on how to use the peptide or its benefits.

The number and diversity of potentially performance-enhancing substances is continuously growing, fueled by new pharmaceutical developments but also by the inventiveness and, at the same time, unscrupulousness of black-market (designer) drug producers and providers. In terms of sports drug testing, this situation necessitates reactive as well as proactive research and expansion of the analytical armamentarium to ensure timely, adequate, and comprehensive doping controls. This review summarizes literature published over the past 5 years on new drug entities, discontinued therapeutics, and 'tailored' compounds classified as doping agents according to the regulations of the World Anti-Doping Agency, with particular attention to analytical strategies enabling their detection in human blood or urine. Among these compounds, low- and high-molecular mass substances of peptidic (e.g. modified insulin-like growth factor-1, TB-500, hematide/peginesatide, growth hormone releasing peptides, AOD-9604, etc.) and non-peptidic (selective androgen receptor modulators, hypoxia-inducible factor stabilizers, siRNA, S-107 and ARM036/aladorian, etc.) as well as inorganic (cobalt) nature are considered and discussed in terms of specific requirements originating from physicochemical properties, concentration levels, metabolism, and their amenability for chromatographic-mass spectrometric or alternative detection methods.