Cyclic Glycine-Proline (cGP): Research Overview

What is Cyclic Glycine-Proline?

Endogenous cyclic dipeptide found in plasma, breast milk, and cerebrospinal fluid. Functions as metabolite of IGF-1, regulating its bioavailability through competitive binding to IGFBP-3. Demonstrates neuroprotective, cognitive-enhancing, and cardioprotective properties supported by clinical trials.

What is Cyclic Glycine-Proline researched for?

• Higher cGP levels correlate with improved memory retention in elderly populations
• Protects neural stem cells from oxidative stress; efficacy demonstrated in stroke models
• Mouse studies show reduced amyloid plaque load and improved spatial memory
• Clinical study showed increased CSF cGP and reduced anxiety/depression scores
• Clinical trial improved vascular complications and normalized HbA1c%
• Demonstrated systolic blood pressure reduction in clinical observations
• Higher cGP/IGF-1 ratios associated with favorable clinical outcomes
• Maintained ratios correlate with preserved cognitive function with age

How does Cyclic Glycine-Proline work?

Competes with IGF-1 for IGFBP-3 binding, normalizing bioavailable IGF-1 levels. Acts as positive allosteric modulator of AMPA and GABA-A receptors. Increases BDNF levels via Akt/MDM2-p53 pathway activation.

References

1. IGF-1 Homeostasis Regulation Study Scientific Reports

   2014

   cGP regulates IGF-1 bioavailability through IGFBP-3 competitive binding

2. Alzheimer's Mouse Model

   Study PMC · 2023

   Significantly improved spatial memory; reduced hippocampal plaques 42.3→14.5 per mm²

   Animal study

3. Parkinson's Disease Clinical

   Study PMC · 2018

   Blackcurrant supplementation increased CSF cGP 74%; reduced anxiety/depression

4. Stroke Recovery & Cognitive Function

   Review PMC · 2023

   Higher cGP/IGF-1 ratios associated with favorable stroke outcomes

Common questions