Cyclic Glycine-Proline
cGPIGF-1 regulating cyclic dipeptide.
Also known as: cGP, Cyclic Gly-Pro
Overview
Cyclic Glycine-Proline (cGP) is a metabolite of IGF-1 studied in neuroprotection and IGF-1 homeostasis research.
A naturally occurring diketopiperazine metabolite of IGF-1, studied for normalizing IGF-1 function — increasing it where deficient and dampening it where excessive. This homeostatic action underlies research interest in neuroprotection and cognitive aging.
Studied for normalizing IGF-1 bioavailability by modulating its binding to IGFBP-3, supporting balanced neurotrophic signaling.
Molecular information
cyclo(Gly-Pro)An endogenous metabolite of the IGF-1 N-terminal tripeptide GPE; orally stable.
Pharmacokinetics
Illustrative relative-concentration model derived from published pharmacokinetic research. Curve is normalized and provided for educational comparison only — not a dosing schedule.
Research applications
- IGF-1 homeostasis research
- Neuroprotection studies
- Vascular-cognitive investigations
Observed effects timeline
Aggregated observations reported across research literature. Timing and magnitude vary by model and are not a guarantee of outcome.
Week 1–4
IGF-1 homeostatic and neuroprotective signaling reported in study models.
Week 4–12
Cognitive and vascular changes reported in aging-related research.
Research compatibility
Describes how compounds are studied alongside one another in the literature. Not a recommendation to co-administer.
Dihexa
Complementary IGF/HGF neurotrophic pathways.
Cerebrolysin
Complementary neurotrophic mechanisms.
P21
Complementary neurogenic pathways.
Quality indicators
Consistent oral form
Research material is typically a capsule or sublingual prep; verify labeled concentration.
Dry storage
As a stable cyclic dipeptide, it does not require cold-chain handling.
Slight clumping
Small clumps that dissolve completely with gentle swirling are acceptable — shipping can cause minor compaction.
Collapsed or melted appearance
Powder that looks collapsed, melted, or stuck to the vial walls may have been exposed to heat in transit.
Cloudy after reconstitution
Persistent cloudiness, particles, or precipitate after gentle mixing can indicate a degraded or contaminated peptide.
Reported observations & safety
Safety signals reported in the research literature. Compiled for scientific awareness — not medical advice.
- Generally reported as well tolerated; as an endogenous metabolite it has a favorable theoretical profile.
- Human data are limited; most evidence is preclinical or association-based.
References & further reading
Cyclic glycine-proline and IGF-1 homeostasis (review)
Review of cGP's role in normalizing IGF-1 function and its neuroprotective implications.
View studyTopics
This entry is provided for educational and informational purposes only. It is not medical advice, a dosing protocol, or a claim of therapeutic benefit. Research compounds are supplied strictly for laboratory and research use — not for human or veterinary consumption.
Active but early-stage research; evidence still developing.
This compound is part of our educational reference and is not currently stocked. Browse the catalogue for available research-grade peptides.
Browse catalogue