Dermorphin
A naturally occurring heptapeptide from frog skin and one of the most potent mu-opioid receptor agonists known, approximately 40 times more potent than morphine.
What is Dermorphin?
Dermorphin is a naturally occurring heptapeptide (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) first isolated in 1981 by Vittorio Erspamer's research group from the skin secretions of South American tree frogs of the genus Phyllomedusa (P. sauvagei and P. bicolor). It is one of the most potent and selective naturally occurring mu-opioid receptor agonists ever discovered, with 30-40 times the analgesic potency of morphine by weight and up to 2,170 times the potency when administered intracerebroventricularly. Dermorphin is notable for containing a D-amino acid (D-alanine at position 2), an extremely rare feature in vertebrate peptides that confers resistance to enzymatic degradation. It has no approved medical use and remains a research compound. It gained notoriety in the 2010s due to its illegal use as a performance-enhancing drug in horse racing.
Why People Talk About It
Potent mu-opioid receptor research tool
ModeratePotential for novel pain management approaches
EmergingIntrathecal analgesia for postoperative and palliative pain
PreliminaryHorse racing doping scandals
ModerateHow It Works
Dermorphin locks onto mu-opioid receptors — the same pain-relief receptors targeted by morphine — but with far greater potency and selectivity. Because it contains an unusual D-amino acid, the body's enzymes break it down much more slowly than typical peptides, so its pain-relieving effects last longer. Unlike morphine, it largely ignores delta and kappa opioid receptors, which may explain why animal studies show somewhat fewer side effects at equivalent pain-relief doses.
Common Questions
Safety Information
Common Side Effects
Cautions
- • Extremely potent opioid — microgram-level dosing errors can be fatal
- • No approved human formulation — purity and dosing are uncontrolled
- • Banned substance in equine and human sport (ARCI Class I, WADA prohibited)
- • Potential for physical dependence with repeated use
- • Respiratory depression can be life-threatening
- • No established human safety profile from large clinical trials
What We Don't Know
Long-term safety in humans is entirely unknown. Only one small clinical trial (intrathecal route, 1985) has been conducted. Abuse potential, chronic toxicity, immunogenicity, and organ-specific effects have not been characterized in humans. The peptide's interactions with other medications are unstudied.
Published Research
16 studiesDermorphin: A Missed Palliative Care Opportunity for Intrathecal Therapy in Oncological Patients?
Argues that dermorphin's favorable intrathecal profile merits revisiting for cancer pain palliation.
Rediscovery of old drugs: the forgotten case of dermorphin for postoperative pain and palliation
Reviews the 1985 clinical trial showing intrathecal dermorphin outperformed morphine for postoperative pain, and argues for renewed clinical investigation.
Detection, quantification, and identification of dermorphin in equine plasma and urine by LC-MS/MS for doping control
Developed the first LC-MS/MS method for detecting dermorphin in horse samples, enabling anti-doping enforcement with limits of detection at 10 pg/mL in plasma.
Dermorphin tetrapeptide analogs as potent and long-lasting analgesics with pharmacological profiles distinct from morphine
Demonstrated that dermorphin analogs produce potent analgesia with less tolerance development than morphine.
Opioid peptide-derived analgesics
Reviews opioid peptide-based drug design including dermorphin-derived analogs as templates for novel analgesics.
Glycodermorphins: opioid peptides with potent and prolonged analgesic activity and enhanced blood-brain barrier penetration
Glycosylated dermorphin analogs showed improved BBB penetration and prolonged analgesia, highlighting potential for drug design.
The dermorphin peptide family
Comprehensive review of the dermorphin peptide family including naturally occurring variants and synthetic analogs, covering structure-activity relationships.
Tolerance and cross-tolerance to the antinociceptive effects of [D-Arg2]-dermorphin tetrapeptide analogue and morphine
Found asymmetric cross-tolerance: morphine-tolerant animals still responded to dermorphin, suggesting distinct receptor interaction profiles.
Amino acid composition and sequence of dermorphin, a novel opiate-like peptide from the skin of Phyllomedusa sauvagei
Landmark 1981 paper by Montecucchi et al. reporting the isolation and structural characterization of dermorphin from frog skin.
Pharmacological data on dermorphins, a new class of potent opioid peptides from amphibian skin
Early pharmacological characterization showing dermorphin is 39 times more potent than morphine on guinea-pig ileum opioid receptors.
Intrathecal dermorphine in postoperative analgesia
1985 clinical trial showing intrathecal dermorphin produced analgesia lasting 43 hours vs 34 hours for morphine, without respiratory depression.
D-Alanine in the frog skin peptide dermorphin is derived from L-alanine in the precursor
Science paper demonstrating that D-Ala in dermorphin is produced by post-translational isomerization from L-Ala in the precursor protein.
Spinal action of dermorphin, an extremely potent opioid peptide from frog skin
Demonstrated dermorphin's spinal antinociceptive action, showing it is 3,000-5,000 times more active than morphine in certain spinal pain models.
Characterisation and visualisation of [3H]dermorphin binding to mu opioid receptors in the rat brain
Radioligand binding study confirming dermorphin's high selectivity and affinity for mu-opioid receptors in the CNS.
Respiratory and locomotor stimulation by low doses of dermorphin, a mu1 receptor-mediated effect
Showed that low doses of dermorphin stimulate respiration and locomotion via mu1 receptors, while high doses depress respiration via mu2 receptors.
Dermorphin-related peptides from the skin of Phyllomedusa bicolor and their amidated analogs activate two mu opioid receptor subtypes that modulate antinociception and catalepsy in the rat
PNAS study demonstrating dermorphin activates two MOR subtypes mediating distinct pharmacological effects (analgesia vs catalepsy).
Related Peptides
Quick Facts
- Class
- Mu-Opioid Receptor Agonist
- Evidence
- Emerging
- Safety
- Use Caution
- Updated
- Apr 2026
- Citations
- 16PubMed
Also known as
Tags
Related Goals
Evidence Score
Clinical Trials
View Clinical TrialsLinks to ClinicalTrials.gov for reference. Listing does not imply endorsement.