Cognitive
Cyclic Glycine-Proline
Cyclic glycine-proline (cGP) is an endogenous cyclic dipeptide metabolite derived from the N-terminal tripeptide of insulin-like growth factor-1 (IGF-1). It modulates IGF-1 bioavailability by competing for binding with IGF-binding proteins, thereby increasing free IGF-1 concentrations. Research has focused on its neuroprotective properties and potential applications in neurodegenerative conditions.
Quick Facts
Also known ascGP
CategoryCognitive
Routesoral, intranasal
Molecular weight154.17 Da
Chain length2 amino acids
Sequencecyclo(Gly-Pro)
FDA statusNot approved
StorageRoom temperature (15-25°C). Reconstituted: 90 days.
Dosing Protocols
| Goal | Dose | Frequency | Route | Cycle | Notes |
|---|---|---|---|---|---|
| General Cognitive Support | 30 mcg | 1x/day | oral | 8 weeks | 20-40mcg once daily oral capsule. 4-12 week cycle. |
| Neuroprotection / Anti-Aging | 45 mcg | 1x/day | oral | 8 weeks | 40-50mcg once daily oral capsule. 4-12 week cycle. |
| Metabolic / Cardiovascular | 70 mcg | 1x/day | oral | 8 weeks | 40-100mcg once daily oral capsule. 4-12 week cycle. |
| Via Blackcurrant Extract | 2x/day | oral | 8 weeks | 300mg blackcurrant extract twice daily. Natural source of cGP. 4-12 week cycle. Dose is extract weight, not cGP mcg. |
Protocols shown are for informational purposes only. Consult a healthcare provider before starting any peptide protocol.
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Start Tracking — FreeCommon Questions
What is the typical dose of Cyclic Glycine-Proline?
A common dose for Cyclic Glycine-Proline is 30 mcg 1x/day via oral. 20-40mcg once daily oral capsule. 4-12 week cycle.
How should I store Cyclic Glycine-Proline?
Store Cyclic Glycine-Proline at Room temperature (15-25°C). Cyclic dipeptide with high oral bioavailability and good chemical stability. Available in capsule form. Found naturally in some foods. Once reconstituted, use within 90 days.
Is Cyclic Glycine-Proline FDA approved?
Cyclic Glycine-Proline is not FDA approved and is available for research purposes only. It has not been evaluated by the FDA for safety or efficacy in humans.
Related Calculators
References
- cGP treatment improved spatial memory and reduced amyloid plaque density in APP/PS1 mice (2023) (pubmed)
- Higher cGP/IGF-1 ratios in stroke patients correlate with favorable outcomes (2023) (pubmed)
- Increased CSF cGP by 74% and reduced anxiety/depression in Parkinson's patients (2018) (pubmed)
- cGP regulates IGF-1 bioavailability through competitive binding to IGFBP-3 (2014) (article)
- Natural cGP supplementation improved protective foot sensation and normalized HbA1c% in type-2 diabetes (2025) (article)
- Oral cyclic glycyl-proline facilitated task learning and functional recovery in stroke rats (2021) (pubmed)
- cGP attenuates hydrogen peroxide-induced cellular damage in neural stem cells via MDM2-p53 pathway (2022) (pubmed)
- NNZ-2591 (cGP Analog) in Phase 2/3 trials for Phelan-McDermid, Rett, Fragile X syndromes (2024) (article)