Cyclic Glycine-Proline vs Selank
Moderate Research vs Well Studied
compatible Complementary cognitive effects; Selank addresses anxiety, cGP optimizes IGF-1
Molecular Data
Cyclic Glycine-Proline Selank
Weight 154.17 Da 751.89 Da
Half-life Extended stability (more stable than linear GPE precursor) 2-10 minutes
Chain 2 amino acids (cyclic) 7 amino acids
Type Cyclic dipeptide (2,5-diketopiperazine) Tuftsin analog
Key Benefits
Cyclic Glycine-Proline
01 Neuroprotection and cognitive enhancement
02 IGF-1 optimization
03 Cardiovascular support
04 Metabolic health improvement
05 Blood-brain barrier penetration
06 Convenient oral administration
Selank
01 Rapid onset anxiolytic effects
02 Enhanced BDNF expression (30% increase)
03 Improved stress resilience
04 Cognitive enhancement
05 Immune modulation
06 No tolerance or withdrawal
07 Neuroprotective effects
Dosing Protocols
Cyclic Glycine-Proline
20-100 μg daily (or 300mg blackcurrant extract 2x daily) / Once daily, preferably in the morning
Selank
250-500mcg per dose / 1-2x daily (morning and/or evening)
Mild anxiety relief 250mcg 1x daily
Moderate anxiety/cognitive 250mcg 2x daily (morning & evening)
Intensive anxiety support 500mcg 1x daily (divided doses)
Cognitive enhancement 250-350mcg 1x daily (morning)
PTSD support 250mcg 2x daily
Immune support 250mcg 1x daily for 2-4 weeks
Side Effects
Cyclic Glycine-Proline
Selank
Minimal side effects - excellent safety profile
No sedation or cognitive impairment
No tolerance, dependence, or withdrawal
Contraindications
Consult healthcare provider if taking IGF-1 or growth hormone medications
Limited long-term human data available
Not studied in pregnancy
Known peptide allergies
Pregnancy or breastfeeding
Consult healthcare provider with multiple psychiatric medications
Research Evidence
Cyclic Glycine-Proline Selank
Status Moderate Research Well Studied
References 4 studies 4 studies
Latest — March 2024
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.