Improving productivity, reducing complexity and mitigating risk is the goal of every Process Development Scientist. For over 20 years, LONG®R3IGF-I (LONG R3) has been a proven cGMP cell culture growth factor used by industry leading biotech companies for commercial biologic processes. 200 times more potent than insulin, available as a lyophilized powder or an easy to use liquid – no other growth factor provides the potency, safety or flexibility for streamlined process development and manufacturing peace of mind.

Better ScienceCompatibilityRegulatory ComplianceSecure Supply

and Repligen

SAFC is Repligen’s exclusive worldwide distributor for LONG®R3 IGF-I in Industrial Cell Culture Applications. Click here for more information.

To learn more about the use of LONG®R3 IGF-I in Stem Cell and Cell Therapy applications, please contact Repligen at

Key benefits - LONG®R3IGF-I

  • Increased cell density, higher viability and extended culture duration
  • 200 times more potent than Insulin and 3 times more stable in cell culture
  • Available as lyophilized powder or ready-to-use liquid formulation
  • cGMP and Animal-free manufacturing process for consistency and regulatory
  • acceptance
  • Security supply backed by comprehensive supply chain risk management.

Better Science

Specificity is the key to increased productivity
Unlike insulin, LONG®R3IGF-I specifically targets and activates the type I IGF Receptor (IGF-IR) resulting in greater activation of downstream signaling cascades responsible for proliferation and inhibiting apoptosis. Greater activation of these key pathways results in increased cell density, higher viability and extended cell culture productivity.

Reduce process complexity through increased potency and stability
LONG®R3IGF-I is more than 200 times more potent than insulin and up to 3 times more stable in cell culture for longer efficacy. Easy cell culture addition with reduced feeding, simplifies process complexity while maintaining optimal performance.

A distinct biological advantage
All mammalian cells secrete IGF Binding Proteins (IGFBPs) which bind to and inhibit native IGF-I. The substitution of an arginine for glutamic acid at position three in LONG®R3IGF-I, in conjunction with the 13 amino acid N-terminal extension peptide, results in > 1000 fold reduced affinity for IGFBPs, thus enhancing its bioavailability and effectiveness in comparison to native IGF-I.


Plug and play with multi cell type compatibility
LONG®R3IGF-I is compatible with multiple cell types including CHO clones, HEK 293, Vero, PerC6, MDCK and fibroblasts. Any mammalian cell type that responds to insulin in cell culture has the potential to respond to LONG®R3IGF-I.

Regulatory Compliance

cGMP and animal-free, with quality and regulatory support straight from the source
LONG®R3IGF-I is manufactured by Repligen according to cGMP following ICH Q7 guidelines ensuring product quality and consistency. In addition, no animal derived substances are used in the production of LONG®R3IGF-I or in the manufacture of the raw materials used to produce LONG®R3IGF-I.

LONG®R3IGF-I has been used in the production of marketed biologics for over 20 years. Currently there are several FDA, EMEA and the Japanese MHW approved therapeutics on the market that use LONG®R3IGF-I, with many more in late-phase clinical trials. Dedicated Product Specialist support is available to guide you through your evaluation and on-going use of LONG®R3IGF-1. Repligen is your partner to provide specialized support to assist with quality, regulatory and audit requirements.

Add it your way - user-friendly formulations for greater flexibility
LONG®R3IGF-I is the only growth factor available as both a lyophilized powder and an easy to use liquid, both stable at 2-8°C. The liquid formulation is ready to use, there is no need to thaw or reconstitute, just open and dilute directly into cell culture media for streamlined supplementation in small or large-scale cell culture processes. LONG®R3IGF-I can also be milled into cell culture media for additional flexibility and convenience.

Save money and time by simplifying inventory and supply chain management
LONG®R3IGF-I is the most stable growth factor on the market. Shipped at ambient conditions and stored at 2-8°C, LONG®R3IGF-I avoids costly coldchain shipping and storage requirements. In addition, LONG®R3IGF-I is 200 times more potent than insulin, requiring less product and a smaller supply chain footprint. ICH Q7 compliant stability trials have confirmed a 5 year shelf life for lyophilized and 3 years (on-going) for the liquid product, allowing customers to purchase large batch sizes and decrease QC costs.

Secure Supply

Supply you can count on backed by a comprehensive risk management strategy
LONG®R3IGF-I has one of the most comprehensive risk mitigation strategies for any cell culture raw material. Repligen manages a global inventory safety stock of over 2 years forecasted demand. This inventory, together with Repligen's multi-site cGMP manufacturing capability, ensures an uninterrupted supply to customers.


LONG®R3 IGF-I is neither approved nor permitted for use in any human application. Repligen provides LONG®R3 IGF-I only to qualified customers expressly for use in cell culture supplementation or for other research purposes.

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