A five-amino-acid peptide that prompts a short burst of growth hormone without the stress-hormone rise older compounds in its family produce. Human study stopped after brief hospital use; no trial has measured muscle, fat, bone, sleep or lifespan. No lawful pharmaceutical supply exists in the United States, gray-market material is often a different molecule, and it is banned in sport. (Full Review)
| Marker | Target | Why |
|---|---|---|
| IGF-1 | Mid-range of the age- and sex-adjusted reference interval; never above the upper limit | Confirms the peptide is producing a real biological effect and caps mitogenic exposure |
| IGFBP-3 | Upper half of the reference range | Interprets IGF-1 by indicating how much is bioavailable rather than protein-bound |
| Fasting glucose | 75–90 mg/dL | Detects the counter-regulatory glycemic drift that is the most likely adverse effect |
| Fasting insulin | 2–5 µIU/mL | Detects insulin resistance well before fasting glucose moves |
| HOMA-IR | Below 1.0 | Single summary index of insulin sensitivity, the metabolic variable most at risk |
| HbA1c | 4.8–5.3% | Captures cumulative glycemic drift that spot fasting values can miss |
| Fasting lipid panel with ApoB | ApoB below 80 mg/dL; triglycerides below 80 mg/dL | Growth hormone alters lipolysis and lipid handling; triglycerides also track the insulin-resistance shift |
| Thyroid-stimulating hormone and free thyroxine | Thyroid-stimulating hormone 0.5–2.0 mIU/L; free thyroxine in the upper half of range | Growth hormone increases peripheral thyroid hormone conversion and can unmask marginal central hypothyroidism |
| Morning cortisol | 10–15 µg/dL at 8 a.m. | Tests directly whether the compound's selectivity claim is holding in this individual under chronic use |
| Prolactin | Below 15 ng/mL in men; below 20 ng/mL in women | Second check on pituitary selectivity, since related peptides raise it |
| Prostate-specific antigen (men aged 40 and over) | Below 1.0 ng/mL at age 40–49; below 2.5 ng/mL thereafter, with velocity below 0.35 ng/mL per year | Screens the tissue most plausibly responsive to IGF-1 elevation |
| Complete blood count and complete metabolic panel | Within reference range | Baseline organ function; growth hormone axis stimulation affects renal sodium handling |
| Blood pressure | Below 120/80 mmHg | Fluid retention from growth hormone raises blood pressure before visible swelling appears |
| Body composition by DXA | Individual trajectory: rising lean mass with stable or falling fat mass | The endpoint the intervention is actually taken for, and the only way to distinguish lean gain from fluid and fat |
Cadence: Baseline fasting panel within 4 weeks of starting, paired with cancer screening current within 6 months; the core panel repeated at 4 weeks, again at 12 weeks or the end of the first cycle, and thereafter every 3–6 months for as long as use continues. Any dose escalation resets the clock and calls for a repeat panel 4 weeks later.