Is a IGF-1 (Insulin-like Growth Factor) worth it?
What it costs, whether to test at home or at Quest or Labcorp, and how to read your results.
Medically reviewed by Youmna DiStefano, MD — updated August 2026
The short answer
Worth it if you're monitoring growth-hormone-axis therapy (GH, secretagogues, or GH-releasing peptides) or investigating a possible GH excess or deficiency with your clinician. IGF-1 is the standard proxy for growth hormone activity because it's stable through the day - one $37.99 draw, no special timing.
Who should order it (and who can wait)
Worth it if you...
- •Anyone using GH secretagogue or GH-releasing peptide therapy who wants objective evidence of what it's doing - IGF-1 is THE marker that moves
- •Baseline-then-retest around any intervention targeting the GH axis (the baseline is what makes the retest interpretable)
- •Working up symptoms of adult GH deficiency or excess (acromegaly) alongside a clinician
- •Biohackers tracking recovery/anabolic status who want a number instead of a feeling
You can probably wait if you...
- •You expect it to diagnose anything alone - IGF-1 is a screening/monitoring marker; confirmation of deficiency or excess involves stimulation/suppression testing a clinician orders
- •You want a general 'aging' readout - IGF-1 declines with age normally, and chasing a young reference range with therapy is a clinical decision, not a lab goal
- •You're on high-dose biotin - pause it 48 hours before the draw (assay interference)
We would rather you order the right test than the most expensive one.
At-home vs Quest vs Labcorp
The most common question we get. The short version: the lab and the result are the same - you are choosing where the blood is drawn.
Walk into a lab
Get drawn at any Quest or Labcorp location - thousands nationwide, often same-day. Best for speed and lowest cost.
At-home draw
Not recommended for this test - it needs a lab-based collection to be accurate.
Same result
Whichever you pick, it is run on the same CLIA-certified analyzers with the same reference ranges.
Standard venous draw at Quest or Labcorp - IGF-1 is stable through the day (unlike growth hormone itself, which pulses), so no fasting and no timing requirements. $37.99 self-pay vs $50 at Quest's consumer store; results in 3-5 business days.
How to read your results
The markers that matter most and what an out-of-range value can mean. Reference ranges vary by lab, age, and sex.
| Marker | Typical range | What it means |
|---|---|---|
| IGF-1 | Age-dependent - labs report an age-adjusted range | IGF-1 naturally peaks in adolescence and declines steadily with age, so results only mean something against your age bracket's range (the report shows it). Within-range and feeling fine = the GH axis is doing its job. Persistently high warrants clinical evaluation (GH excess); low with symptoms is a conversation with a clinician about whether formal GH-deficiency workup makes sense. |
Frequently asked questions
Ready to order your IGF-1 (Insulin-like Growth Factor)?
$37.99, physician-authorized, results in 3–5 business days. No insurance or doctor's visit required.
About this guide
Reviewed August 4, 2026. This is general health information, not medical advice, diagnosis, or treatment. Reference ranges vary by laboratory, age, sex, and clinical context - always interpret results with a qualified healthcare provider. Lab analysis is performed at CLIA-certified Quest Diagnostics and Labcorp facilities.