C-peptide vs Leu-enkephalin
Head-to-head comparison of C-peptide (Connecting peptide (C-peptide)) and Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu) — benefits, dosing, side effects, research data, and where to buy.
Research Score
| Property | C-peptide | Leu-enkephalin |
|---|---|---|
| Category | Pain Management | Pain Management |
| Full Name | Connecting peptide (C-peptide) | Tyr-Gly-Gly-Phe-Leu |
| Molecular Weight | 3020.3 Da | 555.63 Da |
| Half-Life | ~20-30 min | 1-5 minutes in plasma |
| Amino Acids | 31 | 5 |
| Typical Dose | no approved analgesic dose|research-only | 0.1-5 ug per animal |
| Route | IV|subQ | Intrathecal / intracerebroventricular |
| Purity | ≥98% | ≥98% |
| Studies Count | 46 | 1000 |
| Research Status | Pre-clinical | Pre-clinical |
C-peptide Benefits
- ✓diabetic neuropathy research
- ✓nerve function support
- ✓possible analgesic effect
Leu-enkephalin Benefits
- ✓delta-opioid activity
- ✓endogenous analgesic model
- ✓receptor-selective pharmacology
- ✓nociception pathway research
C-peptide Dosing
0.5-1.0 mg/day in research|route varies by protocol
Leu-enkephalin Dosing
Intrathecal 0.1-5 ug per animal|Intracerebroventricular 0.1-2 ug per animal|In vitro 1-100 nM
C-peptide Side Effects
- ⚠injection-site reactions
- ⚠unknown long-term safety
Leu-enkephalin Side Effects
- ⚠sedation
- ⚠constipation-like opioid effects
- ⚠very short plasma stability
Research Overview
C-peptide
C-peptide is not an approved analgesic, but multiple studies have examined its effects on peripheral nerve blood flow and neuropathy outcomes. The strongest relevance is in diabetic neuropathic pain rather than migraine.
Leu-enkephalin
Leu-enkephalin is a standard tool in opioid receptor and pain-transmission research because it helps distinguish delta- from mu-preferring signaling. Its research value is high, but its clinical utility is limited by rapid enzymatic breakdown and delivery challenges.
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