A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding: a critical review.
This critical review examines the emerging use of peptides and peptide analogues as performance-enhancing drugs in both competitive sport and recreational bodybuilding. The authors survey a range of compounds — including growth hormone secretagogues (e.g., Ipamorelin), growth hormone-releasing hormone analogues (e.g., CJC-1295, Sermorelin), and synthetic peptide fragments (e.g., Frag 176-191, KPV) — which are promoted in bodybuilding communities for purported benefits in muscle growth, fat loss, recovery, and anti-inflammation. The review notes that these compounds are attractive partly due to their enhanced receptor selectivity and stability compared to older anabolic agents. However, the authors conclude that clinical evidence supporting their use in sport contexts is limited; most existing research addresses therapeutic applications under controlled medical settings, not the high-dose or stacked protocols typical in bodybuilding. The review identifies potential risks including cardiovascular strain, insulin resistance, dyslipidemia, and psychiatric instability. It also highlights the dangers posed by an unregulated supply chain prone to mislabeling and contamination. Anti-doping detection remains challenging due to peptides' structural similarity to endogenous hormones and short half-lives. A key gap identified is the near-complete absence of population-level prevalence data, particularly for recreational users. The authors characterize peptide use in sport as high-risk and ethically problematic pending longitudinal safety evidence.
Why this grade: This is a narrative critical review synthesizing existing literature rather than generating original experimental or clinical data, so its evidence grade reflects the review study type rather than direct human trial evidence.
The pursuit of pharmacological enhancement in sport has evolved from the widespread use of anabolic-androgenic steroids (AAS) to novel agents such as peptides and peptide analogues. Marketed as more selective and ostensibly safer alternatives, peptides-including growth hormone secretagogues (e.g., Ipamorelin), growth hormone-releasing hormone analogues (e.g., CJC-1295, Sermorelin), and synthetic fragments (e.g., Frag 176-191, KPV)-are promoted for muscle growth, fat metabolism, recovery, and anti-inflammatory effects. Their pharmacological profiles, including enhanced stability and receptor selectivity, have made them attractive in both medical research and bodybuilding communities. Despite their growing popularity, the clinical evidence supporting peptide use in sport is limited. Most published studies examine therapeutic applications under controlled dosing regimens, not the supraphysiological or combined protocols common in bodybuilding. Emerging data highlight potential risks: cardiovascular strain, insulin resistance, dyslipidemia, and psychiatric instability. The largely unregulated supply chain exacerbates these dangers, as products are often mislabeled or contaminated. Regulatory bodies such as the World Anti-Doping Agency (WADA) have responded by expanding detection technologies, yet analytical challenges remain due to peptides' structural similarity to endogenous hormones and short half-lives. Beyond elite sport, the extent of peptide use in the general population is unknown. Anecdotal reports and widespread promotion on social media suggest growing uptake among recreational gym-goers, including younger individuals, but prevalence studies are lacking. This represents a critical gap in current knowledge. In conclusion, peptides represent a new phase in performance enhancement but remain experimental substances with poorly defined long-term risks. Until longitudinal data clarify their safety and prevalence, peptide use in both competitive and recreational settings should be considered high-risk and ethically problematic.
Educational summary of published research — not medical advice. Full text is shown only where licensing permits.