Cognitive
Cyclic Glycine-Proline
Longevity
0
Amino acids
Molecular weight
Peptide
Type
Cyclic Glycine-Proline (cGP) is an endogenous cyclic dipeptide and 2,5-diketopiperazine metabolite derived from the N-terminal of insulin-like growth factor-1 (IGF-1). It regulates IGF-1 bioavailability by competitively binding to IGF-binding protein-3 (IGFBP-3), normalizing IGF-1 activity in a bidirectional, homeostatic manner. Research is predominantly in animal models and observational human studies, with exploratory clinical work examining its role in aging, stroke, Alzheimer's disease, and metabolic disorders.
Top researched benefits
Overview of Cyclic Glycine-Proline
cGP competes with IGF-1 for binding to IGFBP-3, altering the ratio of bound to free IGF-1 in circulation and cerebrospinal fluid. This bidirectional regulation normalizes IGF-1 bioactivity — increasing free IGF-1 when levels are insufficient and dampening excess — while downstream effects include promotion of vascular remodeling, neurogenesis, and synaptic plasticity via IGF-1 receptor pathways.
neurological
- 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
metabolic
- Clinical trial improved vascular complications and normalized HbA1c%
- Demonstrated systolic blood pressure reduction in clinical observations
recovery
- Higher cGP/IGF-1 ratios associated with favorable clinical outcomes
- Maintained ratios correlate with preserved cognitive function with age
Typical Dose
20-100 μg daily (or 300mg blackcurrant extract 2x daily)
Frequency
Once daily, preferably in the morning
Cycle Duration
4-12 weeks
Storage
Powder: store at -20°C in a dry, desiccated environment. Soluble in DMSO (5–10 mg/mL). No established clinical reconstitution protocol; general research practice is refrigeration at 2–8°C after dissolution.
No visual available
Due to this peptide having no amino acids, there is no molecular chain to display.
Chemical Makeup
Key benefits
Normalizes bioavailable IGF-1 by competitively displacing it from IGFBP-3, restoring declining IGF-1 activity in aging and neurodegenerative conditions
Reduces amyloid plaque burden and improves spatial memory in Alzheimer's disease mouse models (APP/PS1 transgenic)
Higher plasma cGP/IGF-1 molar ratios correlate with more favorable functional outcomes in stroke patients across observational studies
Exerts neuroprotective effects against ischemic brain injury by inhibiting apoptosis, reducing neuroinflammation, and supporting neurogenesis in rodent models
Community interest
This peptide is still gaining traction in the community.
IGF-1 Modulator | Neuroprotection & Cognitive Health
This overview is informational and based on aggregated descriptions from studies and user reports.
Was it helpful?YesNoCyclic Glycine-Proline Molecular Information
View the scientifc details of Cyclic Glycine-Proline.
Molecular Weight
154.17DaChain Length
0Amino AcidsType
PeptideCyclic Glycine-Proline Protocols
Oral administration is the primary human-use route for Cyclic Glycine-Proline, supported by clinical trial data and confirmed CNS penetration following oral intake. Traneurocin (NA-831) has been tested at 10–30 mg/day in Alzheimer's disease trials; natural food-derived supplements deliver approximately 40 mcg of cGP per 100 mg of extract.
| Goal | Dosage | Frequency | Route |
|---|---|---|---|
| Improve cognitive function in mild cognitive impairment (MCI) using the lowest effective synthetic cGP dose | 10 | 1 day range | Oral |
| Slow cognitive decline and support neuroprotection in mild-to-moderate Alzheimer's disease | 30 | 1 day range | Oral |
| Prevent cognitive decline in asymptomatic high-risk individuals by restoring IGF-1 bioavailability | 10 | 1 day range | Oral |
| Support IGF-1 homeostasis and general neuroprotection using a physiological dose of natural cGP from blackcurrant extract | 0.04 | 1 day range | Oral — 40 mcg as natural cGP extract (e.g. 100 mg cGP-PRo providing ≥40 mcg cGP) |
| Facilitate cognitive rehabilitation and task-learning recovery following ischemic stroke | — | 1 day range | Oral |
| Reduce vascular complications and support IGF-1 regulation in type-2 diabetes patients | — | 1 day range | Oral (natural cGP supplementation) |
Cyclic Glycine-Proline Cycle
The Cyclic Glycine-Proline Cycle section explains how long a typical cycle lasts and what to expect during each phase. Over time, your body can become less responsive with continuous use.
Taking breaks between cycles may help maintain effectiveness and support better overall results.
- Week 1-2
- Possible subtle improvements in mental clarity
- Week 2-4
- Enhanced cognitive function and focus may become noticeable
- Week 4-8
- Neuroprotective and metabolic benefits accumulating
- Week 8-12
- Optimal IGF-1 regulation and sustained cognitive support
Dosing tools
Cyclic Glycine-Proline Peptide Dosage Calculator
Calculate peptide doses with our visual syringe guide.
mg
Enter the total amount of peptide in the vial in milligrams (as stated on the label).
The dose you want to inject per administration, in mcg or mg.
1,000 mcg = 1 mg
1 mL
2 mL
3 mL
5 mL
Custom
Volume of bacteriostatic water you add to reconstitute the powder. Use BAC water for preservation.
Injection Results
Based on your vial and dilution inputs.
Cyclic Glycine-Proline
SINGLE COMPOUNDVolume per injection
0.05
mL
Concentration
10.00
mg/mL
Doses per vial
20
doses
Total injections per vial
20 injections
How it works
Based on a 10 mg Cyclic Glycine-Proline vial diluted with 1 mL of bacteriostatic water, each 500 mcg injection equals 0.05 mL.
1mL / 100 units
5 units
0.050 mL
Reference Guide
Dosing Cycle
- Peptide
- Cyclic Glycine-Proline
- Dosing
- 20-100 μg daily (or 300mg blackcurrant extract 2x daily)
- Dosing Frequency
- Once daily, preferably in the morning
- Cycle Duration
- 4-12 weeks
- Storage
- Powder: store at -20°C in a dry, desiccated environment. Soluble in DMSO (5–10 mg/mL). No established clinical reconstitution protocol; general research practice is refrigeration at 2–8°C after dissolution.
Note: Triple agonist; microdose for fewer side effects
Reconstitution Tips
- Use bacteriostatic water (BAC) — contains 0.9% benzyl alcohol for preservation
- Inject water slowly — aim down the vial wall, not directly onto powder
- Never shake — gently swirl or roll the vial until dissolved
- Store properly — refrigerate at 2-8°C after reconstitution
- Use within 28 days — most reconstituted peptides remain stable for about 4 weeks
- Keep sterile — always clean vial tops with alcohol before drawing
Peptide Interactions
Research suggestions of Cyclic Glycine-Proline interactions with other common peptides and substances.
Healing
bpc
Longevity
BPC-157
COMPATIBLE
Different pathways; BPC-157 promotes tissue repair, cGP modulates IGF-1
Cognitive
sel
Longevity
Selank
COMPATIBLE
Complementary cognitive effects; Selank addresses anxiety, cGP optimizes IGF-1
Cognitive
sema
Longevity
Semax
COMPATIBLE
Both offer neuroprotection and nootropic effects through distinct pathways
Side effects
Contraindications
Consult healthcare provider if taking IGF-1 or growth hormone medications
Limited long-term human data available
Not studied in pregnancy
Stop signs
Allergic reactions (rash, difficulty breathing, swelling)
Unexpected blood glucose changes
Unusual fatigue or weakness
Bad signs
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Frequently asked questions
What is a peptide dosage calculator?
A peptide dosage calculator is a free tool that converts your vial size, bacteriostatic water volume, and target dose into an exact syringe draw volume. Instead of doing the reconstitution math by hand, you enter three inputs and instantly get the concentration of your solution and how many milliliters or syringeunits to draw. This calculator works for single peptide compounds and multi-peptide blends.
How do I calculate peptide dosage from a vial?
To calculate your peptide dose, divide the total peptide content of your vial in micrograms by the volume of bacteriostatic water you added in milliliters. This gives you your solution concentration in mcg/mL. Then divide your target dose by that concentration to get your draw volume. For example, a 5mg (5,000 mcg) vial reconstituted with 2mL of BAC water gives a concentration of 2,500 mcg/mL. A 250 mcg dose would require drawing 0.1mL. This calculator automates all of those steps instantly.
How much Bacteriostatic water should I add to a peptide vial?
Most people add 2mL to 3mL of bacteriostatic water per vial, but the right amount depends on the dose you want to draw and the syringe size you are using. Adding 1mL to a 5mg vial gives you a concentration of 5,000 mcg/mL, making each dose very small in volume. Adding 2mL gives you 2,500 mcg/mL, which is easier to measure on a standard insulin syringe. A general guideline is to choose a volume that puts your typical dose somewhere between 10 and 30 units on a U-100 syringe. Use the calculator above to test different water volumes and find what works for your dose.
How are peptides different from proteins?
Both are made of amino acids, but peptides are much smaller than proteins. Because of their tiny size, peptides can act like tiny messengers in the body, sending specific signals to your cells to tell them exactly what to do.
Cyclic Glycine-ProlineResearch References
Cyclic Glycine-Proline is an experimental compound
Cyclic Glycine-Proline
Cyclic Glycine-Proline is an experimental compound
IGF-1 Homeostasis Regulation Study
cGP regulates IGF-1 bioavailability through IGFBP-3 competitive binding
n.d.
Alzheimer's Mouse Model Study
Significantly improved spatial memory; reduced hippocampal plaques 42.3→14.5 per mm²
n.d.
Parkinson's Disease Clinical Study
Blackcurrant supplementation increased CSF cGP 74%; reduced anxiety/depression
n.d.
Stroke Recovery & Cognitive Function Review
Higher cGP/IGF-1 ratios associated with favorable stroke outcomes
n.d.
Calculate peptide dosages
Learning how to calculate a peptide dose? Use our beginner-friendly peptide dosage, blend, and accumulation calculators. Enter vial size, reconstitution volume, and target dose to get exact draw volumes instantly. No guesswork, just clear guidance that helps prevent common mistakes.
