Ibutamoren mesylate is an unapproved oral medication, sold to build muscle and slow physical decline, that prompts the body to release more of its own growth hormone, holding the growth factor it controls at young-adult levels for years. Lean tissue increases — yet strength, walking speed and function do not. Blood sugar control worsens, appetite rises, swelling and aching are common early. Nothing has been measured about cancer or death rates. (Full Review)
| Marker | Target | Why |
|---|---|---|
| IGF-1 | Upper half of the age-adjusted reference range, not above it | Confirms drug effect and caps growth-signal exposure |
| Fasting glucose | 70–85 mg/dL | Detects the principal metabolic risk |
| HbA1c | 4.8–5.4% | Shows whether a glucose drift is sustained |
| 2-hour oral glucose tolerance test | Below 120 mg/dL at 2 hours | Catches impairment while fasting glucose still reads normal |
| Fasting insulin | 2–5 µIU/mL | Quantifies the insulin resistance behind the glucose rise |
| ALT and AST | Below 25 U/L (men), below 20 U/L (women) | Detects the liver injury seen in case reports |
| Apolipoprotein B | Below 80 mg/dL | Tracks whether the lipid picture drifts unfavorably |
| Prolactin | Within the laboratory reference range | Detects the modest rise this class produces |
| Morning cortisol | 10–15 µg/dL at 08:00 | Checks the stress-axis drift reported with long-term use |
| NT-proBNP | Below 125 pg/mL | Screens the congestive heart failure signal in older users |
| Blood pressure | Below 120/80 mmHg | Fluid retention raises it, and it modified the heart-failure signal |
| Appendicular lean mass by DXA | No established target; track change from the individual's own baseline | The only benefit the trials demonstrated |
| Bone mineral density | T-score above −1.0 | Growth hormone raises bone turnover in both directions |
Cadence: Baseline panel before the first dose. IGF-1 and fasting glucose at 4 and 12 weeks, then every 3–6 months, as for liver enzymes, lipids and blood pressure. Body composition and bone density every 12 months.