Laboratory Monitoring Reference
Bloodwork Reference Guide
Research-relevant biomarkers organized by compound class. Shows which labs are used as endpoints in published studies, expected direction of change, units, and reference ranges from standard laboratory medicine.
Research reference only. Reference ranges reflect standard clinical laboratory values and published research endpoints. This is not medical or clinical guidance. Laboratory monitoring should be supervised by a qualified investigator or clinician. Full disclaimer.
Growth Hormone Secretagogues
Category: Growth Hormone Secretagogue
| Biomarker | Abbrev. | Why Monitor | Direction | Reference Range |
|---|---|---|---|---|
| Insulin-like Growth Factor 1 | IGF-1 | Primary downstream marker of GH activity; rises with sustained GH elevation | ↑ Monitor for elevation | 115–307 ng/mL (adult) |
| Growth Hormone (fasting) | GH | Baseline and peak GH pulse measurement; elevated by secretagogues | ↑ Monitor for elevation | <1 ng/mL fasting (adult) |
| Fasting Glucose | FBG | GH elevation can induce transient insulin resistance; monitor glycemic impact | ↕ Monitor for any change | 70–100 mg/dL |
| Fasting Insulin | F-Insulin | GH reduces insulin sensitivity; elevated fasting insulin signals resistance | ↑ Monitor for elevation | 2–20 µIU/mL |
| HbA1c | HbA1c | Long-term glycemic marker; important in prolonged GH secretagogue protocols | ↑ Monitor for elevation | <5.7% |
| Total Testosterone (male) | T (total) | GH axis interacts with HPG axis; baseline recommended | ↕ Monitor for any change | 300–1000 ng/dL (male) |
| Prolactin | PRL | Non-selective GHRPs (GHRP-2, GHRP-6, Hexarelin) elevate prolactin; selective agents (Ipamorelin) do not | ↑ Monitor for elevation | 4–15 ng/mL (male) |
| Thyroid-Stimulating Hormone | TSH | GH axis interacts with thyroid axis; monitor in extended protocols | ↕ Monitor for any change | 0.4–4.0 mIU/L |
Research Notes
IGF-1 is the most commonly used endpoint in published GH secretagogue research. Supraphysiological IGF-1 elevation is associated with insulin resistance and potentially acromegalic features with chronic exposure.
↑ Elevation expected or relevant↓ Reduction expected or relevant↕ Any directional change relevant