The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing pharmacology literature and clinical guidance without a systematic review methodology
PubMed 42395176 · doi:10.3389/fendo.2026.1822475
What was done
This narrative review evaluated unregulated performance-enhancing peptides that modulate the growth hormone–insulin-like growth factor-1 (GH-IGF-1) axis, including GHRH analogues (e.g., sermorelin, tesamorelin, CJC-1295), growth hormone secretagogues (e.g., GHRP-2, GHRP-6, hexarelin, ipamorelin), GH fragments (AOD9604), and IGF-1 analogues (e.g., PEG-MGF, IGF-1 LR3). The authors contrasted peer-reviewed pharmacokinetic, pharmacodynamic, and clinical evidence against online self-administration protocols, stratified agents into evidence tiers based on human study availability, reviewed adverse effect profiles, and developed a clinical assessment algorithm for patient evaluation.
What was found
The abstract reports no quantitative effect estimates, sample sizes, or statistical values. Qualitatively, the review identified documented adverse effects including endocrine and metabolic disturbances (elevations in prolactin and cortisol, dysglycaemia, altered appetite), fluid retention syndromes, musculoskeletal symptoms (myalgia and arthralgia), injection-site reactions, and theoretical mitogenic concerns. The authors noted significant uncertainty regarding proposed physique and performance benefits due to the lack of human clinical trials for many agents and unregulated supply chain variables.
Why it matters
With increasing unsupervised use of unregulated GH-IGF-1 secretagogues and analogues, this work gives clinicians an evidence-based assessment framework to evaluate patient exposure, triage symptoms, and communicate health risks without validating unapproved regimens.
Limits
This is a narrative review rather than a systematic review or meta-analysis, with no standardized inclusion criteria or quality assessments reported. The abstract provides no primary human trial data, exact study counts, or quantitative safety/efficacy metrics, and much of the discussed usage is based on unregulated, unverified online self-administration practices.
Cited by
- context Tesamorelin combined with ipamorelin can increase IGF-1 levels into the 380s or 390s ng/mL.