What is IGF-1 LR3 (Receptor Grade)?
is a synthetic long-acting analog of insulin-like growth factor-1 (IGF-1) designed for research into cell growth signaling.
“Receptor grade” is a vendor classification, not an official medical or regulatory standard. It usually means:
- Higher claimed purity (often ~99%)
- Intended for strong IGF-1 receptor binding studies
- Used in lab or in-vitro research contexts
Example listings describe it as a modified IGF-1 variant used to study:
- Cellular proliferation
- PI3K/Akt and MAPK signaling pathways
- Growth factor receptor activation (Peptides Sciences Store)
What “1mg vial” actually means
A listing like:
👉 IGF-1 LR3 (receptor grade) 1mg
typically refers to:
- 1 milligram of freeze-dried peptide powder
- Stored in a sealed vial
- Sold as research-use-only material
Common vendor wording:
“For laboratory research use only, not for human consumption” (Core Peptides)
What “receptor grade” really means (important)
Despite the name sounding advanced, it is not a regulated pharmaceutical grade.
It usually indicates:
- Higher purity batch testing (vendor-defined)
- Marketing tier above “media grade”
- Not an official scientific or FDA classification
So:
👉 “Receptor grade” = marketing + internal quality label, not a clinical certification.
What IGF-1 LR3 does in research
In experimental settings, IGF-1 LR3 is studied for:
Growth signaling
- Activates IGF-1 receptors (IGF-1R)
- Stimulates anabolic cell pathways (PI3K/Akt)
Cellular metabolism
- Protein synthesis pathways
- Glucose uptake signaling
Tissue growth models
- Muscle cell proliferation
- Repair/regeneration studies
Why it’s heavily marketed online
It’s popular in “biohacking” spaces because it is associated (in theory, not clinical use) with:
- Muscle growth signaling
- Recovery pathways
- Anti-aging research themes
But most human claims online are extrapolated from lab or animal studies, not approved clinical use.
Important reality check
Even though it’s widely sold:
- ❌ Not FDA-approved
- ❌ Not a prescription medication
- ❌ No standardized human dosing
- ❌ Not regulated for consumer use
- ✔ Classified as a research peptide
Key takeaway
(including “receptor grade” versions) is a lab-research growth factor analog used to study cellular growth signaling, but “1mg receptor grade” products sold online are unregulated laboratory materials—not approved medicines or safe consumer products.
