Dermorphin Research & Listing Availability

How it works

Dermorphin is a seven-amino-acid peptide — tyrosine-D-alanine-phenylalanine-glycine-tyrosine-proline-serine with a C-terminal amide — originally isolated from the skin of *Phyllomedusa* tree frogs by Vittorio Erspamer's group in the early 1980s.[1][4] Two features of the structure are pharmacologically unusual. First, the D-alanine residue at position 2 is one of the only known naturally occurring D-amino-acid residues in a vertebrate peptide; the inverted stereochemistry blocks aminopeptidase cleavage at the most metabolically labile position and gives dermorphin a substantially longer in-vivo half-life than its all-L-amino-acid backbone would otherwise produce. Second, the molecule binds the mu-opioid receptor with both very high affinity and very high mu-selectivity — substantially more mu-selective than morphine, with binding constants in the sub-nanomolar range and analgesic potency roughly 1000× greater than morphine on a molar basis in rodent tail-flick and hot-plate assays.[2][4] Negri and colleagues characterised the molecule's ability to activate two mu-opioid receptor subtypes with different effects on antinociception and catalepsy, which is the basis of its continued use as a research tool for dissecting mu-receptor pharmacology.[2] Despite the unusually clean pharmacological profile, dermorphin has had no serious human therapeutic development; the molecule is unstable enough that oral dosing is impractical, and the field moved toward synthetic mu-selective ligands designed from first principles rather than from amphibian-skin peptide leads.

Active research areas

• Mu-opioid receptor pharmacology (research tool)
  Dermorphin remains a standard research tool for high-affinity, high-selectivity mu-opioid receptor pharmacology — used for mu-receptor binding-site mapping, mu-receptor desensitisation kinetics, and mu-vs-delta receptor selectivity benchmarking.[1][2][5]
• Horse-racing doping (dominant real-world use)
  Dermorphin came to broad public attention in 2012 when extensive positive tests across multiple US racetracks — Mongongu et al. characterised the LC-MS/MS analytical method used in the equine doping-control program[3] — led to ARCI enforcement actions, the molecule's formal classification under racing rules, and trainer suspensions.[6] Equine analgesia and behavioural-suppression effects make it attractive for race-day administration despite its lack of any approved veterinary use.
• No human therapeutic program
  Despite the extraordinary potency and selectivity, dermorphin has had **no human therapeutic development.** Modern opioid drug discovery has favoured synthetic small-molecule mu agonists with better oral bioavailability and manufacturing tractability than amphibian-skin peptides.