Objective:

To map the main GH–IGF-1–modulating peptides used off-label (i.e., for purposes not approved by regulatory agencies), summarise pharmacokinetic/pharmacodynamic and human evidence, synthesise endocrine–metabolic adverse effects, and compare clinical evidence with patient self-administration protocols.

Approach:

Key Findings:

• Performance-enhancing drugs marketed as 'research compounds' include unregulated peptides targeting the GH–IGF-1 axis, such as GHRH analogues (e.g., sermorelin, tesamorelin), GHS (e.g., GHRP-2, GHRP-6), GH fragments (e.g., AOD9604), and IGF-1 analogues (e.g., PEG-MGF).
• Adverse effects reported include endocrine and metabolic disturbances, fluid retention, musculoskeletal symptoms, and injection-site reactions.
• The review highlights the uncertainty around performance benefits due to the lack of regulatory approval and variability in product composition.

Interpretation:

Clinicians require a pragmatic framework to interpret symptoms and laboratory abnormalities in patients using these compounds, given the absence of robust long-term data and the need for clinical guidelines.

Limitations:

• The evidence on GH–IGF-1-axis PEPs is highly heterogeneous regarding compounds, populations, endpoints, and study design, and the review is limited to English-language sources, which may impact the comprehensiveness of the findings.

Conclusion:

The review aims to support clinicians in recognizing potential harms and framing risk in the absence of robust long-term data, emphasizing the importance of awareness regarding the risks of unregulated use.

Attribution Notice

This content is an AI-generated, fully rewritten summary based on a published scholarly article. It does not reproduce the original text and is not a substitute for the original publication. Readers are encouraged to consult the source for full context, data, and methodology.