How much human trial data exists for research peptides
It varies by roughly two orders of magnitude, and the variation is not where a casual reader of vendor catalogues would expect it. Counting indexed PubMed records for eighteen compounds on 31 August 2026 using one consistent query per compound, the number of records carrying a clinical-trial or randomised-controlled-trial publication type ran from 141 at the top to zero at the bottom. Several compounds that appear constantly in research-peptide discussion have no trial-tagged records at all, while the compounds with substantial trial literatures are mostly the ones that went through conventional pharmaceutical development. Volume of discussion and volume of controlled human evidence are close to unrelated quantities, and the point of counting them side by side is to make that gap visible rather than to rank compounds.
How was this counted, and what does the count miss?
Each compound was searched in title and abstract fields with its common synonyms, then filtered two ways: once by humans[mh], and once by publication type randomized controlled trial[pt] OR clinical trial[pt]. Same method, same day, same database.
Four limitations matter enough to state before the numbers.
Publication types are assigned by MEDLINE indexers and are imperfect: a genuine trial can go untagged, and a review discussing trials is not itself tagged as one. Second, records are not trials, since one trial commonly generates several publications. Third, some queries over-collect. "melanotan" retrieves work on afamelanotide, an approved α-melanocyte-stimulating hormone analogue, and on melanotan-I, neither of which is melanotan-II. "thymosin beta 4" retrieves a large literature on the endogenous protein and on the ophthalmic formulation RGN-259, which is full-length thymosin β4 rather than the TB-500 fragment sold under that name. Fourth, title-and-abstract searching misses papers that use only an alternative designation.
The counts are therefore an order-of-magnitude indicator, not a census. They are reported here because the differences between compounds are far larger than the error the method introduces.
| Compound | All records | Human-tagged | Trial-tagged |
|---|---|---|---|
| Tirzepatide | 2426 | 1319 | 141 |
| Tesamorelin | 94 | 75 | 23 |
| PT-141 / bremelanotide | 112 | 82 | 16 |
| Cagrilintide | 94 | 57 | 14 |
| Melanotan (all analogues) | 249 | 81 | 8 |
| Retatrutide | 170 | 103 | 7 |
| MOTS-c | 253 | 142 | 5 |
| Thymosin β4 / TB-500 | 622 | 342 | 4 |
| Semax | 207 | 46 | 4 |
| Selank | 68 | 15 | 3 |
| Ipamorelin | 50 | 24 | 2 |
| CJC-1295 | 33 | 21 | 2 |
| GHK-Cu | 130 | 47 | 1 |
| Epithalon | 116 | 37 | 1 |
| BPC-157 | 219 | 51 | 0 |
| AOD-9604 | 22 | 18 | 0 |
| KPV | 17 | 6 | 0 |
| 5-Amino-1MQ | 3 | 3 | 0 |
Which compounds carry a substantial controlled literature?
The upper rows are dominated by compounds developed through conventional regulatory pathways. Tirzepatide's 141 trial-tagged records reflect a completed phase 3 programme published in general medical journals (for the obesity programme, see New England Journal of Medicine, 2022;387(3):205–216; PMID 35658024, DOI 10.1056/NEJMoa2206038). Tesamorelin and bremelanotide follow the same pattern at smaller scale, both having reached approval for defined indications; the bremelanotide phase 3 work was published as two randomised trials in Obstetrics and Gynecology, 2019;134(5):899–908 (PMID 31599840, DOI 10.1097/AOG.0000000000003500).
This is not a statement that these compounds are better in any respect. It is a statement about how much independent, controlled, published human evidence exists to argue from — which is a different property, and the only one being counted here.
Which have almost none, and what does that mean?
Four compounds returned no trial-tagged records at all. Their situations are not equivalent.
BPC-157 returns 219 indexed records, 51 human-tagged, and zero with a trial publication type. The 219 is real, but it is overwhelmingly preclinical, and a substantial share of it comes from a single research programme. A 2026 narrative review assessing the compound from a drug-development perspective concluded that despite more than three decades of preclinical work, its pharmaceutical development remains rudimentary, with no approved formulation and no completed phase 2 clinical trial, and reported that the available clinical data derive from fewer than 30 subjects across three uncontrolled pilot studies, none using standardised pharmaceutical preparations (Pharmaceutics, 2026;18(5):625; PMID 42198317, DOI 10.3390/pharmaceutics18050625). Earlier work refers to trials in inflammatory bowel disease conducted under the designations PL-10, PLD-116 and PL 14736 (Inflammopharmacology, 2006;14(5–6):214–21; PMID 17186181, DOI 10.1007/s10787-006-1531-7), which is why the compound is sometimes described as having been in clinical trials. Both things are true at once: a clinical programme was begun, and no completed controlled trial has been published.
AOD-9604 returns 22 records, of which the substantive metabolic characterisation is animal work in obese Zucker rats (Hormone Research, 2000;53(6):274–8; PMID 11146367, DOI 10.1159/000053183). Much of the more recent literature concerns analytical detection and in vitro metabolism in an anti-doping context (Drug Testing and Analysis, 2015;7(1):31–8; PMID 25208511, DOI 10.1002/dta.1715). I could not locate a peer-reviewed publication reporting a completed human obesity trial for this compound, and have not asserted one.
5-Amino-1MQ returns three records in total. The preclinical case for inhibiting its target enzyme, nicotinamide N-methyltransferase, rests largely on work with other inhibitors — for instance a small-molecule NNMT inhibitor characterised in diet-induced obese mice, ob/ob and db/db mice, and NNMT knockout controls (Scientific Reports, 2018;8(1):3660; PMID 29483571, DOI 10.1038/s41598-018-22081-7). That is a literature about a mechanism, not about this molecule in humans. KPV returns 17 records on the same pattern.
A near-zero count is not evidence that a compound does nothing. It is evidence that the question has not been asked in a form that produces controlled human data, and that any confident claim about human effects is therefore running ahead of the record.
Where a trial does exist, how large is it?
Small enough that the trial-tagged column flatters several compounds.
GHK-Cu's single trial-tagged record is a randomised study of copper tripeptide skin-care products following carbon dioxide laser resurfacing, in which thirteen patients completed. Computer analysis and blinded evaluators found no statistically significant difference between groups for resolution of erythema, and objective evaluation found no significant improvement in wrinkles or overall skin quality; a difference appeared only in patient-reported questionnaire scores (Archives of Facial Plastic Surgery, 2006;8(4):252–9; PMID 16847171, DOI 10.1001/archfaci.8.4.252). The thymosin β4 entry includes a phase 2 randomised trial in severe dry eye with nine patients enrolled (Cornea, 2015;34(5):491–6; PMID 25826322, DOI 10.1097/ICO.0000000000000379) — and that trial studied full-length thymosin β4 in an ophthalmic formulation, not the TB-500 fragment.
MOTS-c illustrates a different pattern again: 253 records and 142 human-tagged, but the human-tagged work is largely observational, measuring circulating peptide concentrations in cohorts. The originating characterisation was mechanistic and rodent-based (Cell Metabolism, 2015;21(3):443–54; PMID 25738459, DOI 10.1016/j.cmet.2015.02.009).
The melanotan row deserves its own caution. Its eight trial-tagged records are substantially afamelanotide's, and a review of the unregulated use of α-MSH analogues notes that afamelanotide is the only such analogue approved for any indication, while describing case reports of melanocytic changes and reporting that four case reports have described melanomas emerging from existing moles during or shortly after melanotan use (International Journal of Dermatology, 2017;56(10):975–980; PMID 28266027, DOI 10.1111/ijd.13585).
Why does this matter when reading a supplier catalogue?
Because a catalogue is organised by availability, and availability is uniform in a way the evidence is not. Eighteen compounds presented in the same format, with the same certificate structure and specification fields, can imply eighteen comparable evidence bases. They are not comparable.
Analytical data and evidentiary weight are also separate things, and worth keeping separate. A certificate establishes what is in a particular vial from a particular batch — see, for example, BPC-157 batch 2026-03, GHK-Cu batch 2026-03, MOTS-c batch 2026-03, NAD+ batch 2026-03 and Retatrutide batch 2026-03. A well-attributed certificate on a compound with no controlled human literature is exactly that: a reliable statement about the material, and no statement whatever about what the compound does.
Veridian Research supplies these materials strictly for in-vitro laboratory research. They are not drugs and are not approved for human or veterinary use.
The short version
Across eighteen compounds counted the same way on the same day, trial-tagged records ranged from 141 to zero, and four compounds had none. The compounds with substantial controlled literatures are largely those taken through conventional development. Several of the most-discussed compounds have literatures that are large, preclinical, and in places concentrated in a single research programme. Where trials exist they are often very small, and in at least one case the published objective endpoints were null. Anyone reasoning from this catalogue should check which column their compound sits in before deciding how much weight the literature can carry.