Research Tool
IGF-1 Response
Estimator
Estimate IGF-1 % elevation from GH secretagogue stacking based on published clinical and preclinical pharmacology data. Includes GHRH analog + GHRP synergy modeling, duration modifiers, and dosing frequency adjustments. Research reference only.
⚠️ Research reference only — estimates are based on published study data and should not be used to guide human dosing decisions. All output is illustrative.
Compound Mode
Compound Selection
Mono IGF-1 elevation: 35%–50%
Half-life: 12 min
Synergy multiplier: 1.8–2.8×
Half-life: 2h
Protocol Parameters
Near-peak IGF-1 elevation
Age 40: ~100–150 ng/mL typical
Estimated IGF-1 Response
Estimated IGF-1 elevation above baseline
Estimated absolute IGF-1 at steady state
235–360 ng/mL
Based on 150 ng/mL baseline
Calculation Breakdown
GHRH Analog
View Product →Sermorelin
GHRH-R (Gs/cAMP/PKA/CREB) agonist — first 29 aa of native GHRH
📋 Pulsatile GH pattern. Pituitary reserve required. Nocturnally timed dosing optimal.
GHRP / GHS
View Product →Ipamorelin
Selective GHSR-1a agonist (D-2-Naphthylalanine structure) — no cortisol/ACTH activation at research doses
📋 Cleanest GHRP profile — no cortisol, no appetite stimulation. Preferred stack partner.
Published IGF-1 Elevation Reference — All GH Secretagogues
| Compound | Type | IGF-1 Range | Duration | Key Study |
|---|---|---|---|---|
| Sermorelin | GHRH Analog | 35%–50% | 4–12 weeks | Sigalos & Pastuszak 2018 (Sexual Medicine Reviews) |
| CJC-1295 No DAC (Mod GRF 1-29) | GHRH Analog | 35%–55% | 4–12 weeks | Alba 2006 (J Clin Endocrinol Metab) |
| CJC-1295 with DAC | GHRH Analog | 50%–80% | 4–12 weeks | Teichman 2006 (J Clin Endocrinol Metab) |
| Tesamorelin | GHRH Analog | 40%–55% | 4–12 weeks | Falutz 2007 (NEJM) |
| MK-677 (Ibutamoren) | Standalone GHS | 40%–65% | 8–24 weeks | Nass 2008 (Annals of Internal Medicine) |
| GHRH + Ipamorelin | Stack | 65–155% | 8–12 weeks | Bowers 1998; Johansen 1999 |
| GHRH + GHRP-2 | Stack | 80–195% | 4–8 weeks | Arvat 1997 |
| GHRH + Hexarelin | Stack | 90–220% | 2–4 weeks | Ghigo 1994 |
* Stack ranges assume optimal frequency (5–7×/week) and 8–12 week duration. Actual results vary by species, sex, age, pituitary reserve, and somatostatin tone.
Research Design Considerations
Pituitary Reserve
GHRH analogs require intact somatotroph function. Verify baseline GH response before attributing IGF-1 changes to the compound. Use GHRH stimulation test as inclusion criterion.
IGF-1 as Biomarker
IGF-1 has ~18-hour half-life — ideal for monitoring GH axis activity. Measure at consistent time (morning fasted) for reproducible comparisons. ELISA coefficient of variation typically 6–8%.
Somatostatin Tone
Endogenous somatostatin blunts GH pulse amplitude. GHRP co-administration partially overcomes somatostatin inhibition. High-fat diet models may have elevated somatostatin baseline.
Tachyphylaxis
GHRP compounds (especially hexarelin) show significant receptor desensitization. Build washout periods (2–3 weeks) between study arms. Rotate compounds in long-duration protocols.
Sex Differences
Female rodents typically show higher GH pulse frequency but lower amplitude vs males. Estradiol sensitizes GHRHr. Use sex-matched controls and report sex as variable.
Combination Controls
Always include: vehicle control, GHRH analog alone, GHRP alone, and GHRH+GHRP combination. This 2×2 design quantifies additive vs synergistic effects.
Related Tools
Research Use Only Disclaimer: All estimates in this tool are derived from published preclinical and clinical pharmacology studies and represent population-level ranges, not individual predictions. IGF-1 response is influenced by species, age, sex, baseline pituitary function, diet, exercise, and concomitant compounds. This tool is intended solely as a reference for qualified researchers designing study protocols. It does not constitute medical advice and should not be used to guide human self-administration decisions.