PEG-MGF is a laboratory-made copy of a fragment muscle appears to release for repair, joined to a chemical chain meant to make it last longer. The case rests on cell and animal work; no human study has been published. Supportive research comes largely from the patent-holding laboratory, one paper was withdrawn, it is banned in sport; no lawful supply exists. (Full Review)
| Marker | Target | Why |
|---|---|---|
| IGF-1 | 100–160 ng/mL in adults over 40 | Detects growth-axis stimulation; flags a mislabelled product |
| IGFBP-3 | 3.0–4.5 mg/L | Contextualises IGF-1; most of it is bound, not free |
| Prostate-specific antigen | Below 1.0 ng/mL, with velocity under 0.35 ng/mL per year | Key safety marker; proliferative activity shown in prostate cancer cells |
| Fasting glucose and HbA1c | Glucose 75–90 mg/dL; HbA1c 4.8–5.4% | Detects disordered glucose handling in this peptide class; flags insulin-like contamination |
| Comprehensive metabolic panel | ALT/AST below 25 U/L; creatinine age-appropriate; eGFR above 90 mL/min/1.73 m² | Detects liver or kidney injury; tracks polyethylene glycol clearance |
| Creatine kinase | 50–200 U/L | Separates training damage from drug-related muscle injury |
| High-sensitivity C-reactive protein | Below 1.0 mg/L | Detects systemic inflammatory or immune response, or injection-site infection |
| Complete blood count with differential | Within reference range; eosinophils below 5 percent | Detects injection-site infection and the eosinophil rise of hypersensitivity |
Cadence: Baseline within two weeks before starting, after 72 hours without heavy training; repeat at 8 weeks, at the end of any cycle, then every 6 months. Prostate-specific antigen in men also at 3 and 12 months.