F

F tier · safety concern

A mu-opioid agonist reported at roughly 30 to 40 times the potency of morphine by weight, with no approved human medical use anywhere, no human safety database, and a public record consisting chiefly of racehorse doping enforcement; the overdose and respiratory-depression risk is real and unmitigated.

dermorphin

ULTRA-POTENT MU-OPIOID HEPTAPEPTIDE

also: frog juice · sapo · Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2

Dermorphin is a naturally occurring opioid heptapeptide from the skin of South American Phyllomedusa frogs whose D-alanine residue confers protease resistance and extreme mu-opioid receptor selectivity. It has no approved human medical use and is known publicly almost entirely through horse-racing doping enforcement, where it is classified among the most severe prohibited agents.

// we supply this one

available as a research reagent

≥ 98% HPLC · lyophilised powder · batch certificate published. Grade F above is our own and is not adjusted because we stock it.

from £26.95

per 2 mg

view product →

the explanation

Dermorphin is a painkilling chemical originally found in the skin of South American tree frogs, and it is reported to be roughly 30 to 40 times stronger than morphine for the same weight. It is not an approved medicine anywhere, it became known mainly because trainers were caught giving it to racehorses, and like any strong opioid it can stop a person breathing.

regulatory status

No approved human medical use; Class 1 prohibited substance in horse racing

Dermorphin has no marketing authorisation for human use in any jurisdiction and no recognised investigational medicinal product status. The Association of Racing Commissioners International added dermorphin to its Class 1 category, the most severe classification, in 2011, with recommended first-offence penalties of at least a one-year suspension and a fine of USD 10,000 or ten percent of the purse, whichever is greater.

how it works · proposed mechanism

Dermorphin is a high-affinity, highly selective agonist at the mu-opioid receptor.

Mu-opioid receptor agonism

Dermorphin binds the mu-opioid receptor with high affinity and marked selectivity over delta and kappa subtypes. Receptor activation produces the full canonical opioid profile including analgesia, sedation, euphoria and respiratory depression.

D-alanine protease resistance

The D-alanine residue at position 2 is not a substrate for mammalian aminopeptidases, which would otherwise rapidly degrade the N-terminal tyrosine. This unusual stereochemistry is the structural reason the peptide survives long enough to act at high potency.

Potency without a safety margin

Reported potency of roughly 30 to 40 times morphine by weight means that the mass differences separating an analgesic effect from respiratory arrest are correspondingly compressed. No human dose-ranging or therapeutic-window data exist to define where those boundaries lie.

together → The pharmacology is well characterised and is precisely what makes the compound dangerous outside a controlled clinical setting.

what’s reported

~30-40x morphinereported potency by weight in analgesia assays
0approved human medical uses worldwide
31+US racehorse positives reported across three states in 2012

evidence shape

5 sources

The composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.

official / regulatory1
randomised trials0
observational3
reviews0
preclinical1

⚠ the catch

There is no human clinical literature to grade because dermorphin has never been developed as a human medicine; the entire public evidence base is chemistry, animal pharmacology and doping enforcement. Anything with mu-opioid agonism at tens of times morphine's potency and no established human dosing carries a genuine risk of fatal respiratory depression, and that risk is not hypothetical.

key published findings

  • Structure and origin (in vitro / chemistry): dermorphin is the heptapeptide H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2 (C40H50N8O10, 802.89 g/mol, CAS 77614-16-5) isolated from the skin of South American frogs of the genus Phyllomedusa and described in a 1981 publication as a new class of potent opioid peptides.
  • Preclinical pharmacology (rodent): dermorphin is reported to be approximately 30 to 40 times more potent than morphine by weight, an effect attributed to high mu-opioid receptor selectivity combined with the protease resistance conferred by the D-alanine at position 2.
  • Doping enforcement (equine, observational): during the 2012 US racing season 15 horses tested positive in Oklahoma, more than 10 runners in Louisiana (7 Quarter Horses and 3 Thoroughbreds) between mid-May and early June, and 6 samples in New Mexico; the first confirmed positive involved the horse Dashin Forward in May 2012.
  • Regulatory classification (official): the Racing Commissioners International added dermorphin to its Class 1 drug category in 2011, with recommended minimum first-offence penalties of a one-year suspension and a USD 10,000 fine or ten percent of the race purse, whichever is higher.
  • Analytical detection (equine, method development): LC-MS/MS methods for the detection, quantification and identification of dermorphin in equine plasma and urine were developed and published for doping control, which is what made the 2011 to 2012 wave of positives detectable at all.

limitations of the evidence

  • There are no human clinical trials of dermorphin at all, so no human efficacy, tolerability, pharmacokinetic or therapeutic-window data exist to evaluate.
  • Potency figures relative to morphine derive from animal analgesia assays and vary by model, route and endpoint, so the 30 to 40 fold range should not be treated as a fixed conversion.
  • The doping-case record documents detection and enforcement rather than physiological outcomes, so it says little about dose-response or toxicity thresholds.

documented safety signals

  • Mu-opioid agonism produces dose-dependent respiratory depression; at reported potencies of 30 to 40 times morphine, the absolute mass separating effect from respiratory arrest is very small and has never been characterised in humans.
  • Full opioid agonism carries the standard risks of physical dependence, tolerance, withdrawal and addiction.
  • Combined central nervous system depression with alcohol, benzodiazepines, gabapentinoids or other opioids substantially increases the risk of fatal respiratory depression.
  • No pharmaceutical-grade human product exists, so material in circulation has unverified identity, purity, concentration and sterility, and a concentration error translates directly into an overdose.
  • The compound is a Class 1 prohibited substance in horse racing, the most severe category, reflecting both its potency and its abuse potential.
  • No human antidote protocol has been established for dermorphin specifically, although it is a mu-opioid agonist and opioid-receptor antagonism is the established pharmacological countermeasure for this receptor class.

identity

full nameDermorphin
categoryOther
modalitypeptide
formulaC40H50N8O10
molar mass802.89 g/mol
cas77614-16-5
sequenceH-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2

laboratory handling

storageLyophilised peptide is typically stored desiccated at -20 C and protected from light. Handling information only; this compound has no approved human use.
solubilitySoluble in water and aqueous buffers; the amidated C-terminus and Tyr/Ser residues give it good aqueous solubility.
co-studied withNo combination data exist. Documented pharmacology indicates that co-exposure with other central nervous system depressants compounds respiratory depression risk, which is the principal reason this compound is graded F.

Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.

the receipts

5 cited
Dermorphin

Wikipedia · 2026 · reference

The Tree Frog Drug: Combating the Latest Racetrack Cocktail

Paulick Report · 2012 · investigative journalism

Rash of Dermorphin Positives in Ruidoso Futurity Qualifying

Paulick Report · 2012 · investigative journalism

Illegal 'Frog Juice' Detected in Racehorses

Kentucky Equine Research (Equinews) · 2012 · industry technical report

others in Other

Research use only. dermorphin is catalogued here as a research reagent. Nothing on this page is medical advice, a treatment recommendation, or a dosing protocol. This compound is not for human consumption.