Sermorelin, a laboratory-made peptide given by injection, copies the brain signal that tells the pituitary gland to release growth hormone and is used to raise the body's own growth hormone, which falls with age. It reliably does so in older adults, but health benefits remain largely unproven: better thinking-task scores come from one research group, sleep did not improve, and blood sugar and cancer questions remain open. (Full Review)
| Marker | Target | Why |
|---|---|---|
| IGF-1 | Within the age- and sex-adjusted reference range, below its upper limit | Expected to change; safety check for growth hormone excess |
| Fasting glucose | Below 100 mg/dL | Safety check for blood sugar rises |
| HbA1c | Below 5.7% | Safety check for blood sugar rises |
| TSH and free T4 | TSH 0.4–4.0 mIU/L; free T4 0.8–1.8 ng/dL | Safety check for unmasked hypothyroidism |
| Fasting triglycerides and LDL cholesterol | No established target; track change from baseline | Safety check for lipid rises |
| PSA (men) | No established target; track change from baseline | Safety check; persistent rise stops use |
| Lean mass and fat mass by DEXA | No established target; track change from baseline | Expected to change |
Cadence: Baseline before starting; IGF-1 at 4–6 weeks and after any dose change, then every 3–6 months; fasting glucose, HbA1c and thyroid tests every 3–6 months; lipids and PSA every 6–12 months; repeat body-composition scan at 6 months