Dalargin
A Soviet-developed synthetic enkephalin analog studied mainly for gastroprotective and anti-ulcer activity through peripheral opioid receptors.
Dalargin (D-Ala2-Leu5-Arg6-enkephalin) is a synthetic hexapeptide opioid receptor agonist developed in the Soviet Union as a stable enkephalin analog. A D-amino acid substitution makes it resistant to enzymatic degradation, and because it penetrates the central nervous system poorly it acts with a peripheral preference. It has been investigated for gastroprotective and analgesic properties, primarily in animal models and limited Russian clinical use, and has no approval in any Western jurisdiction.
Class
Synthetic hexapeptide (enkephalin analog / opioid receptor agonist)
Routes
Subcutaneous, Intravenous
Category
Healing & Recovery
Researched benefits
What it's studied for
Gastroprotection
Dalargin is proposed to protect the gastric mucosa through opioid receptor-mediated suppression of gastric acid secretion and stimulation of mucosal prostaglandin synthesis. In rats with indomethacin-induced injury it significantly reduced the area of erosive and ulcerative lesions.
GI mucosal repair
In preclinical work the peptide normalized epithelial cell proliferation in damaged gastric tissue, supporting a role in promoting epithelial repair after mucosal injury.
Anti-ulcer activity
The compound inhibits ulcer formation via prostaglandin-mediated pathways and has been used in Russian clinical practice for peptic ulcer disease, though without randomized controlled trials meeting current methodological standards.
Pain modulation
As an enkephalin analog binding mu and delta opioid receptors, dalargin has demonstrated central analgesic activity in preclinical studies, in addition to its peripheral gastrointestinal effects.
Reduced oxidative stress
In the indomethacin gastropathy model, dalargin decreased oxidative stress markers in gastric tissue, suggesting an antioxidant component to its mucosal protection.
Mechanism
How it works
Dalargin binds delta and mu opioid receptors. Because of its limited central nervous system penetration it acts with a peripheral preference, concentrating its effects on the gastrointestinal tract rather than producing the central opioid effects of classical enkephalins.
In the stomach, activation of these opioid receptors reduces gastric acid secretion, promotes mucosal blood flow, and stimulates mucosal prostaglandin synthesis. Together these actions defend the gastric lining against injury and inhibit ulcer formation via prostaglandin-mediated pathways.
Beyond acute protection, dalargin appears to support epithelial repair by normalizing the proliferation of gastric epithelial cells and by lowering oxidative stress in damaged tissue. Its D-amino acid substitution (D-Ala at position 2) confers resistance to enzymatic degradation, extending its activity relative to native enkephalin.
Its opioid receptor agonism also produces central analgesic activity in preclinical models, so the peptide has been characterized as both a gastroprotective and an analgesic agent.
Evidence
Research & clinical studies (1)
Gastroprotective effect of dalargin in gastropathy due to treatment with nonsteroid antiinflammatory drugs
In rats with indomethacin-induced gastric injury, dalargin significantly reduced the area of erosive and ulcerative lesions, normalized epithelial cell proliferation, and decreased oxidative stress markers, demonstrating gastroprotective and mucosal repair activity via opioid receptor pathways.
PMID 19704944Safety
Side effects & considerations
Contraindications & cautions
- Pregnancy or nursing
Dalargin is generally considered lower risk in research contexts, but its human safety profile has not been validated by independent clinical investigation. Individual response varies, and as an opioid receptor agonist its full side-effect profile in humans is not well characterized in indexed literature.
FAQ
Dalargin — common questions
What is Dalargin?
Dalargin (D-Ala2-Leu5-Arg6-enkephalin) is a synthetic hexapeptide opioid receptor agonist developed in the Soviet Union as a stable enkephalin analog. A D-amino acid substitution helps it resist enzymatic degradation, and it has been investigated for gastroprotective and analgesic properties in animal models and limited Russian clinical use.
What is Dalargin primarily studied for?
Its main studied areas are gastroprotection, GI repair, anti-ulcer activity, and pain modulation.
How does Dalargin work?
It binds mu and delta opioid receptors with a peripheral preference due to limited CNS penetration. In the stomach this suppresses gastric acid secretion, promotes mucosal blood flow, stimulates prostaglandin synthesis, and supports epithelial repair, while its opioid activity also produces central analgesia.
What does the research show about Dalargin?
The main indexed study found that in rats with indomethacin-induced gastric injury, dalargin significantly reduced erosive and ulcerative lesions, normalized epithelial cell proliferation, and decreased oxidative stress markers in gastric tissue.
What are the side effects of Dalargin?
It is generally considered lower risk in research contexts. The main reported contraindication is pregnancy or nursing. Its full human safety profile has not been validated by independent clinical trials.
Is Dalargin approved or legal?
Dalargin has no FDA approval and no regulatory approval in any Western jurisdiction. It has been used historically in Russian clinical practice for peptic ulcer disease but is otherwise an obscure research-only compound.
