IGF-1
Insulin-like Growth Factor-1
The hormone GH actually works through
The primary anabolic mediator of growth hormone. Most of GH's effects on muscle, tissue repair and growth are actually carried out by IGF-1, produced mainly in the liver. Native IGF-1 is short-acting and tightly regulated by binding proteins — making the IGF axis one of the most genetically variable in the body.
- Half-life
- ~10–12 min (native)
- Route
- Subcutaneous injection
- Typical dose
- Research-dependent
- Availability
- Research-only
Key Benefits
Direct anabolic signaling for muscle and repair
Carries out most of growth hormone's effects
Supports tissue regeneration and recovery
Well-characterized biology and receptor pathway
Pairs naturally with GH-axis peptides
Mechanism of Action
How IGF-1 works
IGF-1 is the downstream effector of the growth hormone axis:
- IGF-1 receptor (IGF1R) activation — binds IGF1R to trigger the PI3K/Akt/mTOR pathway that drives protein synthesis, cell growth and repair.
- GH-dependent production — GH signals the liver to produce IGF-1, so most of GH's anabolic effect is really IGF-1's. The GHR d3 genotype sets how efficiently this conversion runs.
- Binding-protein regulation — native IGF-1 is mostly bound to IGFBP-3, with only a small free, active fraction and a short half-life — unlike the engineered LR3 analog.
- Shared insulin signaling — IGF1R overlaps with insulin signaling, giving IGF-1 glucose-lowering effects that depend on individual metabolic genetics.
Your Genetics & IGF-1
Genetic variants that affect your response
These SNPs determine how effectively IGF-1 works for you specifically. A genetic peptide report identifies your variants before you start.
This promoter variant sets your baseline circulating IGF-1. Low-expressers run a lower IGF-1 set point, which shapes both their GH response and how supplemental IGF-1 layers on.
Variants in the IGF-1 receptor gene change signaling efficiency at the direct target. Receptor sensitivity sets how strongly the anabolic cascade fires for a given IGF-1 level.
The -202 A/C variant determines IGFBP-3 levels — the main carrier of IGF-1. This sets the bound-versus-free balance and therefore how much active IGF-1 is available.
The GHR d3 polymorphism governs how efficiently GH is converted to IGF-1 in the liver, setting your endogenous IGF-1 baseline.
Which variants do you carry?
Upload your DNA data or order a kit to find out.
Evidence & Research
45+
Published studies
Published human or robust animal studies with clear mechanistic rationale
Sourcing & access
Where to buy IGF-1
IGF-1 is sold as a research compound, not a licensed medicine, so quality and legal status vary widely by country and vendor. If you're sourcing it, treat independent purity testing as non-negotiable.
- Insist on a recent third-party Certificate of Analysis (COA) for the exact batch — labs like Janoshik verify purity and identity.
- Check the legal status where you live before ordering — it differs from country to country.
- Reconstitute correctly with bacteriostatic water and start at a conservative dose.
Swiss Chems is a US research-chemical supplier that publishes third-party Certificates of Analysis. Sold for research use only — check your local laws.
Before you buy: see whether your DNA actually responds to IGF-1, and at what dose. Analyze my DNA — $99 →
Educational information only, not medical advice. Some outbound links are affiliate links (disclosed, at no extra cost to you), and providers we partner with are listed first. Most peptides are not FDA-approved — consult a qualified professional and check your local laws before purchasing.
Common Stacks
IGF-1 is commonly combined with:
CJC-1295
GH/IGF Axis StackModerate EvidenceCJC-1295 (Modified GRF 1-29)
A 29-amino-acid growth hormone releasing hormone (GHRH) analog with enhanced stability. CJC-1295 extends the duration of natural GH pulses without disrupting pulsatile release patterns, providing sustained elevation of growth hormone and IGF-1 for recovery, body composition, and anti-aging.
4
Gene variants
30+
Studies
BPC-157
Recovery StackModerate EvidenceBody Protection Compound 157
A 15-amino-acid peptide derived from human gastric juice. The most-researched peptide for tissue repair, gut healing, and injury recovery. Works through nitric oxide signaling, angiogenesis, and collagen stimulation.
4
Gene variants
100+
Studies
Frequently Asked Questions
What is the difference between IGF-1 and IGF-1 LR3?
Native IGF-1 is the body's own hormone — short-acting (minutes) and mostly bound to binding proteins. IGF-1 LR3 is an engineered analog that resists those binding proteins and lasts for hours, making it far more potent. Both act on the same IGF-1 receptor; the difference is duration and free-fraction.
Why is IGF-1 tied so closely to growth hormone?
Growth hormone exerts most of its anabolic effects indirectly — by telling the liver to produce IGF-1. So your IGF-1 level is the practical readout of GH activity, and the GHR d3 genotype, which sets GH-to-IGF-1 conversion efficiency, strongly shapes both.
Does genetics affect IGF-1 response?
Yes. IGF1 promoter variants set your baseline, IGF1R variants determine receptor sensitivity, IGFBP3 status sets the free-versus-bound balance, and GHR d3 governs GH-to-IGF conversion. A genetic peptide report profiles the whole axis for you.
Learn More About IGF-1
Your next move
Two ways forward with IGF-1.
Not sure it's for you?
Will IGF-1 work for your genes — and at what dose?
Your report scores IGF-1 against your receptor, CYP and pathway variants — likely responder, non-responder, and a sensible starting dose — in minutes.
Analyze my DNA — $99Already decided?
Get IGF-1 from Swiss Chems.
A US research-chemical supplier with third-party Certificates of Analysis. Sold for research use only — check your local laws before ordering.
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