Dermorphin vs Glepaglutide
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2, Frog juice
Dermorphin is a seven-amino-acid opioid peptide (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) first found in the skin of South American Phyllomedusa frogs. It is a strong, highly selective mu-opioid agonist, the same receptor morphine and fentanyl hit, and in mouse brain-injection studies it was hundreds of times more potent than morphine. It is not approved anywhere for human use. Its main claim to fame is doping: it was caught in dozens of American racehorses in 2012, where it was nicknamed 'frog juice'. This is an opioid, and it should be treated like one.
Also: ZP1848, Zeydovio
Glepaglutide is Zealand Pharma's long-acting GLP-2 analog for short bowel syndrome, built to be injected once or twice a week instead of daily like teduglutide. Its path has been bumpy. The FDA rejected it in December 2024 because the single phase 3 trial only worked at the twice-weekly dose, but Europe went the other way: in September 2026 the EMA's CHMP recommended approval under the name Zeydovio. As of late October 2026 the final European Commission decision is still pending, and the US needs another trial.
Key Comparison Insights
- Both peptides belong to the Healing category, suggesting similar primary applications.
- Glepaglutide has stronger research evidence (Human Trials) compared to Dermorphin (Animal Studies).
Detailed Comparison
| Attribute | Dermorphin | Glepaglutide |
|---|---|---|
| Category | Healing | Healing |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | Dermorphin binds the mu-opioid receptor with very high affinity and selectivity. In rat brain binding work it had a Ki of 0.7 nM at mu receptors versus 62 nM at delta and over 5,000 nM at kappa receptors, a selectivity on par with the reference lab mu-agonist DAMGO. It is unusual for a natural peptide because its second amino acid is a D-alanine, which protects it from the enzymes that normally chew up opioid peptides within seconds. Mu activation blocks pain signaling in the spinal cord and brain, and it also drives the classic opioid problems: euphoria, sedation, slowed breathing, constipation, tolerance and dependence. There is no special 'safe' mechanism here. Claims that it is less addictive than morphine are mostly marketing and horse-racing talk, not proven in people. | Glepaglutide activates the GLP-2 receptor in the intestine, the same target as teduglutide, which makes the gut lining grow and absorb more fluid and nutrients. What is different is the delivery. After a subcutaneous injection it forms a depot and is slowly released, mostly as two active metabolites rather than the parent molecule. In a healthy-volunteer study the effective half-life was roughly 88 to 124 hours, long enough to make weekly or twice-weekly dosing plausible. The flip side is the same as the rest of the GLP-2 class: anything that makes gut tissue grow raises questions about polyps and tumors over the long run. |
| Common Dosing | No safe human dose established Not established | 10 mg twice weekly (trial dose) Twice weekly |
| Administration | Intravenous infusion (human study); intravenous or intramuscular (horse study) | Subcutaneous injection (prefilled pen in the EU filing) |
| Typical Duration | Single administrations in research settings | 24 weeks in EASE-1, with longer-term extension studies |
| Best Time to Take | Not applicable | Same days each week (trial schedule) |
Possible Side Effects May vary by individual |
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| Research Summary | Most of the science is animal pharmacology and drug-testing chemistry. A 1990 rat-brain study confirmed dermorphin as a near-specific mu 'super-agonist' and found that, injected into the brains of mice, it was up to 670 times more potent than morphine as a painkiller, with higher doses causing catalepsy. The human data are tiny: a 1986 Brain Research study gave an intravenous infusion of 0.16 mg/kg to healthy volunteers and found a marked, long-lasting rise in the threshold of a spinal pain reflex; naloxone only reversed about half the effect. No modern clinical trials exist. In horses, a 2015 pharmacokinetic study (about 9 mcg/kg IV or IM) found an elimination half-life under an hour, excitation with a raised heart rate after IV dosing, and detection in urine for 48 to 72 hours. The doping story is the reason most people have heard of it: around 30 positive tests turned up in Southern US racing in 2012, including 11 horses tied to nine trainers in Louisiana, which led to suspensions of up to 10 years, and racing labs in Australia, the US and Hong Kong have since built sensitive tests for dermorphin and its synthetic analogs. A 2017 federal indictment charged a Louisiana veterinarian with supplying it to trainers. | The main evidence is EASE-1, published in Gastroenterology in April 2025 (Jeppesen and colleagues). It randomized 106 adults with SBS and intestinal failure to glepaglutide 10 mg twice weekly, 10 mg once weekly, or placebo for 24 weeks. Twice weekly cut weekly parenteral support by 5.13 L versus 2.85 L on placebo (p=0.0039), and 65.7% were responders versus 38.9% on placebo. Once weekly (3.13 L) did not reach significance. A handful of patients came off IV support completely, none on placebo. On 19 December 2024 the FDA issued a complete response letter saying there was not enough evidence at the to-be-marketed dose and asked for another trial; Zealand is running EASE-5 to support a US resubmission. Zealand filed in Europe in June 2025 and the CHMP gave a positive opinion on 17 September 2026 for adults with SBS (10 mg prefilled pen). Common side effects listed by the EMA are injection site reactions, abdominal pain, nausea, and vomiting. Bottom line: real phase 3 data, but from a single trial with one of two doses positive, which is exactly why the two regulators disagreed. |
Frequently Asked Questions: Dermorphin vs Glepaglutide
What is the difference between Dermorphin and Glepaglutide?
Dermorphin is a healing peptide that dermorphin is a seven-amino-acid opioid peptide (tyr-d-ala-phe-gly-tyr-pro-ser-nh2) first found in the skin of south american phyllomedusa frogs. it is a strong, highly selective mu-opioid agonist, the same receptor morphine and fentanyl hit, and in mouse brain-injection studies it was hundreds of times more potent than morphine. it is not approved anywhere for human use. its main claim to fame is doping: it was caught in dozens of american racehorses in 2012, where it was nicknamed 'frog juice'. this is an opioid, and it should be treated like one. Glepaglutide is a healing peptide that glepaglutide is zealand pharma's long-acting glp-2 analog for short bowel syndrome, built to be injected once or twice a week instead of daily like teduglutide. its path has been bumpy. the fda rejected it in december 2024 because the single phase 3 trial only worked at the twice-weekly dose, but europe went the other way: in september 2026 the ema's chmp recommended approval under the name zeydovio. as of late october 2026 the final european commission decision is still pending, and the us needs another trial. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Dermorphin or Glepaglutide?
Neither is universally "better" - the choice depends on your specific goals. Dermorphin is typically used for healing purposes, while Glepaglutide is used for healing. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Dermorphin and Glepaglutide be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Dermorphin and Glepaglutide together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.