---
title: "What is the molecular weight of IGF-1 LR3? | Sable Peptides"
description: "The molecular weight of IGF-1 LR3 is 9111.0 g/mol on the registry record used for identity. It is classed as a recombinant protein analogue (83 residues)."
canonical: https://www.sablepeptides.co.uk/questions/igf-1-lr3-molecular-weight
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# What is the molecular weight of IGF-1 LR3?

The molecular weight of IGF-1 LR3 is 9111.0 g/mol on the registry record used for identity. It is classed as a recombinant protein analogue (83 residues). Synonyms include Long R3 IGF-I. Laboratories use this mass when confirming identity by mass spectrometry.

Mass. The expected average mass for identity confirmation is 9111.0 g/mol.

Analytical note. Sable's release specification is ≥99% by HPLC with identity confirmed against the expected mass (quality page). Research use only. Not a medicine. Not for human or veterinary use.

## Sources

-   [https://www.sigmaaldrich.com/GB/en/product/sigma/i1271](https://www.sigmaaldrich.com/GB/en/product/sigma/i1271)

## IGF-1 LR3: reference facts

4 IGF-1 LR3 values, each linked to its public source; see the [IGF-1 LR3 reference page](/ref/igf-1-lr3).

| Synonyms | Long R3 IGF-I (sigmaaldrich.com) |
| --- | --- |
| Compound class | recombinant protein analogue (83 residues) (sigmaaldrich.com) |
| Molecular weight | 9111.0 g/mol (sigmaaldrich.com) |
| Storage (lyophilised) | -20 °C, dry, protected from light (sigmaaldrich.com) |

## Sizes and prices at Sable

| Vial | Price | Per mg | UK same-size check (2026-10-16) |
| --- | --- | --- | --- |
| 0.1 mg | £10.23 | £102.30 | lowest other £30.00 across 1 UK sellers |
| 1 mg | £32.98 | £32.98 | lowest other £34.95 across 13 UK sellers |

Multi-vial pricing on the same item: 3+ vials 10% off, 5+ vials 15% off, 10+ vials 20% off. Every lot has a certificate of analysis: [CoA library](/coa).

## Typical analytical method

| HPLC column | C18 reversed-phase (300 A pore, C4/C8 suitable for large/lipidated) |
| --- | --- |
| Mobile phase | A: water + 0.1% TFA; B: acetonitrile + 0.1% TFA; linear gradient (e.g. 5-65% B over 20-30 min) |
| Detection | 214-220 nm (peptide bond) |

General literature method. The lot CoA records the method actually used. [How to read an HPLC chromatogram](/learn/how-to-read-an-hplc-chromatogram).

## Lyophilised storage on file: IGF-1 LR3

From the Sable storage reference (lyophilised material only; temperature, light, moisture). Literature basis is linked per row. See [peptide storage](/learn/peptide-storage-and-solubility).

| Compound | Lyophilised storage | Light / notes |
| --- | --- | --- |
| IGF-1 LR3 | -20 C long term (-80 C acceptable), sealed and desiccated; 2-8 C for weeks | protect from light; no specific sequence liabilities identified from sequence data on file (source) |

## Typical analytical method: IGF-1 LR3

Reference HPLC and MS conditions from the Sable analytical-methods file; a lot's CoA states the method actually used. See [how to read a CoA](/guides/how-to-read-a-coa).

| Compound | HPLC column / detection | MS / expected ion |
| --- | --- | --- |
| IGF-1 LR3 | C18 reversed-phase (300 A pore, C4/C8 suitable for large/lipidated); 214-220 nm (peptide bond) | ESI-MS (positive mode); LC-MS for identity; [M+3H]3+ ~3038.0; [M+4H]4+ ~2278.8; [M+5H]5+ ~1823.2; [M+6H]6+ ~1519.5 |

Research use only. Not a medicine. Not for human or veterinary use.