Method
How to evaluate peptide research
Most claims about research peptides rest on cell or animal studies. Those studies are useful for generating hypotheses, but most findings in animals do not hold up in human trials. Knowing what kind of study sits behind a claim is the fastest way to judge it.
The evidence ladder
Each profile in our library carries one of five labels, based on the strongest evidence available:
- Approved medicine. A regulator reviewed controlled trial data and approved it for at least one use. Approval for one use does not transfer to others.
- Human RCTs. Randomized controlled trials exist, but not an approval for the use being discussed.
- Early human data. Small, uncontrolled or pharmacology-only studies in people.
- Animal studies. The main evidence is from rodents or other animals.
- Cell studies. The main evidence is from cultured cells or biochemical assays.
Why animal results often fail
Mice differ from people in metabolism, lifespan, immune function and drug handling. Animal studies often use young, genetically identical animals, a single sex, and injuries induced in a standardized way. Doses are frequently far higher, relative to body weight, than anything tested in people. Reviews of translation from animal studies to human trials have found that a minority of positive animal findings are later confirmed in humans.
Single-lab literatures
Two of the most discussed peptide literatures come largely from one group each: BPC-157 from the University of Zagreb, and the short peptide bioregulators from the St. Petersburg Institute of Bioregulation and Gerontology. A body of work from one group can be consistent without being independently confirmed. Look for replication by unrelated laboratories.
Surrogate endpoints
A surrogate is a measurement that is expected to predict a clinical outcome, such as IGF-1 levels for growth hormone activity or telomere length for ageing. Changes in surrogates do not guarantee clinical benefit. Ipamorelin raised GH convincingly, but did not speed bowel recovery after surgery in a phase 2 trial.
Press releases versus papers
Companies often announce topline results months before publication. These are real data, but without the full methods, every endpoint and the safety tables, they cannot be checked in the same way. We label such results as company-reported.
Questions to ask of any claim
- Was it studied in people, animals or cells?
- Was there a control group, and was it randomized and blinded?
- How many participants or animals, and for how long?
- Was the outcome something that matters to people, or a surrogate?
- Who funded and ran the study, and has anyone else reproduced it?
- Was the compound tested the same as the one being sold?
Related profiles
- Synthetic pentadecapeptide BPC-157 BPC-157 is a synthetic 15-amino-acid peptide studied mainly for tendon, ligament, muscle and gut healing in rodents. Animal studies
- Short peptide bioregulator Epitalon Epitalon is a four-amino-acid peptide developed by Vladimir Khavinson’s group as a synthetic version of a pineal gland extract. Animal studies
- Selective ghrelin-receptor agonist Ipamorelin Ipamorelin is a five-residue ghrelin-receptor agonist described in 1998 as the first selective growth hormone secretagogue. Human RCTs
Questions
If a peptide works in mice, will it work in people?
Often not. Animal results are a starting point. Many promising compounds fail in human trials for lack of effect or for safety reasons.
Is a Russian approval evidence that a peptide works?
It means a regulator accepted the evidence presented to it. Standards and trial designs differ between countries, and many such approvals rest on small trials that have not been replicated elsewhere.
References
- Hackam DG, Redelmeier DA. (2006). Translation of research evidence from animals to humans. JAMA.