IGF-1 Optimal Ranges by Age: What Research Shows
IGF-1 declines with age but standard lab ranges are built on average populations. Learn what research shows about optimal IGF-1 ranges and how to track changes on peptide protocols.
Quick Summary IGF-1 (Insulin-like Growth Factor 1) is the primary downstream marker of growth hormone activity. It declines predictably with age and is the key biomarker tracked in research on GH-releasing peptides like tesamorelin, ipamorelin, CJC-1295, and sermorelin. This article explains what published research shows about IGF-1 ranges and why tracking trends matters more than single draws. Educational content only -- not medical advice.
What IGF-1 Measures
IGF-1 is produced primarily in the liver in response to growth hormone signaling. Unlike growth hormone itself, IGF-1 has a longer half-life and remains relatively stable throughout the day -- making it a far more practical lab marker.
Research consistently uses IGF-1 as the primary efficacy marker in GH peptide trials including tesamorelin HIV lipodystrophy trials and multiple ipamorelin studies.
Track your IGF-1 across draws at [myprotocolstack.com/labs](https://myprotocolstack.com/labs) to visualize how your levels are responding.
IGF-1 Research Reference Ranges by Age
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Note: Educational reference points from published literature. Your provider determines what is appropriate for your situation.
Why IGF-1 Declines With Age
Research shows growth hormone secretion declines approximately 14% per decade after age 30. The consequences studied in research include reduced muscle protein synthesis, increased visceral adiposity, decreased bone mineral density, and impaired recovery.
GH Peptides and IGF-1: What Research Shows
Tesamorelin -- FDA-approved for HIV-associated lipodystrophy. Published trials show IGF-1 increases of 60-100 ng/mL above baseline at standard research doses. See the [tesamorelin calculator](https://myprotocolstack.com/calculators/tesamorelin).
Ipamorelin + CJC-1295 -- Research shows synergistic IGF-1 elevation. See the [ipamorelin calculator](https://myprotocolstack.com/calculators/ipamorelin).
Sermorelin -- Older GHRH analogue with strong published safety record. More modest IGF-1 elevation than tesamorelin.
How to Interpret Your IGF-1 Results
Upload your lab results at [myprotocolstack.com/labs](https://myprotocolstack.com/labs) and use [StackAI](https://myprotocolstack.com/stackai) to analyze your IGF-1 in context of your full panel.
Markers to Track Alongside IGF-1
Fasting Glucose and Insulin, ALT and AST (liver enzymes), Fasting Insulin/HOMA-IR, and IGFBP-3.
FAQ
What is a good IGF-1 level?
The trend across your personal draws before and after protocol changes is more informative than any single target number.
How long does it take for GH peptides to raise IGF-1?
Published research typically shows measurable changes within 4-8 weeks of consistent use.
Does sleep affect IGF-1?
Yes. Research shows the majority of growth hormone is secreted during slow-wave sleep. Chronic sleep deprivation is associated with lower IGF-1.
Should I fast before an IGF-1 blood draw?
IGF-1 is relatively stable throughout the day. A consistent draw time is more important than fasting status.
What happens if my IGF-1 goes above the lab reference range?
Values above the standard lab range are worth discussing with your provider. Research protocols include periodic IGF-1 monitoring.
*This article is for educational purposes only. Consult a licensed healthcare provider before starting any peptide protocol.*
*Written by the MyProtocolStack team. Last updated: January 2026.*
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