Trust Signals
Key Takeaways
- ClinicalTrials.gov held over 500,000 registered studies as of 2025, but registration alone proves nothing about a peptide's efficacy or safety.
- BPC-157, Ipamorelin, TB-500, and most wellness-market peptides have zero completed Phase II or III human RCTs in any major registry as of mid-2025.
- Research has consistently shown that a substantial share of registered trials do not post results within 24 months of completion, meaning the visible database is a partial record at best.
- GLP-1 agonists and teriparatide represent the clearest contrast: multiple large, completed, independently replicated RCTs with validated clinical endpoints.
- Phase and status filters on ClinicalTrials.gov are the single highest-use tool for separating signal from noise when evaluating any peptide claim.
What Is a Clinical Trial Peptides Database and Why Does It Matter?
A clinical trial peptides database is any publicly accessible registry or archive that catalogs prospectively registered human studies investigating peptide compounds, covering safety, pharmacokinetics, and efficacy. The primary registries are ClinicalTrials.gov (US), the WHO ICTRP global portal, and EudraCT/CTIS (EU). Together they form the authoritative record of what has actually been tested in humans, at what dose, in what population, and with what result. For anyone evaluating a peptide's real-world credibility, this record is the starting point, not marketing copy and not rodent studies.
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- Which databases cover peptide clinical trials
- How to search effectively: step-by-step
- Evidence ledger: peptides by trial depth
- What most pages get wrong about registry data
- Understanding trial phases with real numbers
- What the registries do not show you
- Head-to-head: researched peptides vs. wellness-market peptides
- How to read a trial record: operational label literacy
- FAQ
- Sources
Which Databases Actually Cover Peptide Clinical Trials?
There are four registries worth knowing. Each covers a different jurisdiction and has different data depth.
| Registry | Jurisdiction | URL | Peptide Coverage | Free Results Data? |
|---|---|---|---|---|
| ClinicalTrials.gov | US (FDAAA 801 mandate) | clinicaltrials.gov | Largest English-language volume | Yes, via Results tab and API |
| WHO ICTRP | Global (17 registries aggregated) | trialsearch.who.int | Best for non-US peptide trials | Links to source registries |
| EU CTIS / EudraCT | European Union | clinicaltrialsregister.eu | Strong for EU-sponsored peptide drugs | Protocol-level, not always results |
| ISRCTN Registry | UK and international | isrctn.com | Good for UK academic peptide studies | Yes for published studies |
PubMed is not a trial registry but is the essential parallel search for published results. Cross-referencing an NCT number in PubMed frequently reveals whether a registered trial produced a peer-reviewed publication.
How Do I Search ClinicalTrials.gov for a Specific Peptide?
The advanced search interface at clinicaltrials.gov/search is more precise than the home page bar. Use these four steps:
- Intervention field: Enter the peptide's INN (e.g., "semaglutide") or its common chemical descriptor. Avoid trade names as your primary term since registry entries are inconsistent.
- Study Type filter: Set to "Interventional" to exclude observational and registry-only records.
- Phase filter: Run separate searches for Phase 2 and Phase 3 to locate efficacy-level evidence. Phase 1 records tell you about safety and dosing only.
- Status filter: Filter first for "Completed" to find trials that reached their endpoint, then check for posted results or linked publications. "Terminated" records are worth reading to understand why the trial stopped.
Export results as CSV for any peptide with more than 20 trials so you can sort by enrollment size and primary outcome type without clicking through individual records.
Evidence Ledger: Peptides Ranked by Clinical Trial Depth
| Peptide | Best Evidence Type | No. of Completed Phase III RCTs (approx, ClinicalTrials.gov, mid-2025) | Effect Direction | Confidence Rating |
|---|---|---|---|---|
| Semaglutide (GLP-1 agonist) | Multiple large human RCTs | 10+ | Weight, glucose: strong positive | High |
| Teriparatide (PTH analog) | Human RCTs, FDA-approved | 5+ | Bone density: positive | High |
| Oxytocin (intranasal) | Human RCTs, mixed results | Multiple Phase II/III | Social behavior: inconsistent | Moderate (positive signal, inconsistent replication) |
| Thymosin alpha-1 | Human RCTs (mostly Asia) | Several Phase II/III | Immune modulation: modest positive | Moderate |
| Ipamorelin (GHRP) | Small human studies, no Phase III | 0 | GH pulse: positive in small studies | Low |
| BPC-157 | Animal/in vitro only | 0 | Tissue repair: positive in rodents | Very Low (no human RCT data) |
| TB-500 (Thymosin beta-4) | Animal/in vitro only | 0 | Wound/repair: positive in rodents | Very Low (no human RCT data) |
| Selank / Semax | Small Russian clinical studies | 0 (in WHO ICTRP) | Anxiolytic/cognitive: limited | Very Low (no replicated RCTs in major registries) |
Approximate Phase III counts reflect searches conducted May 2025. Numbers change as trials complete. Always run a current search before citing figures.
What Most Pages Get Wrong About Registry Data
A well-documented problem in clinical research is that a large share of registered trials never post results publicly, even after completion. Anderson et al. published a compliance analysis in the New England Journal of Medicine (2015, vol. 372, pp. 1031 to 1039) examining results reporting at ClinicalTrials.gov and found that results-posting rates were substantially below what FDAAA 801 requires, with the shortfall especially pronounced for industry-sponsored trials that ended unfavorably. Separately, the broader literature on publication bias consistently shows that negative and inconclusive trials are underrepresented in any public-facing database. This means the clinical trial peptides database landscape you can read publicly is systematically missing negative and inconclusive results. When you find only two completed trials for a peptide and both show positive signals, publication bias is a plausible alternative explanation to genuine efficacy.
A second error common on competitor pages: confusing "registered" with "completed" and "completed" with "published positive results." These are three separate bars, and most peptides clear only the first.
A third error: treating Phase I pharmacokinetic data as evidence of efficacy. A Phase I trial that shows a peptide achieves measurable blood levels and does not cause acute harm proves nothing about whether it does what the seller claims.
Understanding Trial Phases With Real Numbers
Phase labels carry specific statistical implications that most lay summaries strip out.
| Phase | Typical Enrollment | Primary Question | What a Positive Result Means | What It Does Not Mean |
|---|---|---|---|---|
| Phase I | 20 to 100 subjects | Is it safe at escalating doses? What is the PK? | Tolerable short-term safety profile, measurable exposure | It works for any clinical indication |
| Phase II | 100 to 300 subjects | Is there a preliminary efficacy signal? What dose? | Signal worth pursuing in a larger trial | Effect size is reliably estimated or generalizable |
| Phase III | 300 to several thousand subjects | Does it work better than placebo or standard of care? | Pre-specified efficacy endpoint met with adequate power | It will be approved; long-term safety is fully characterized |
| Phase IV | Thousands (post-approval) | Real-world safety and effectiveness | Post-market surveillance data exists | All rare adverse events are captured |
What the Registries Do Not Show You (the Section Most Pages Skip)
This is the most operationally important section on this page.
Unpublished and proprietary data. Pharmaceutical sponsors are not required to register pre-IND (investigational new drug) studies, in vitro screens, or animal work. The positive rodent data that generates peptide marketing claims never appears in any registry. You are reading the tip of a very large iceberg, and the hidden portion is structurally more likely to contain failures.
Compounded and off-label use. When a clinic administers a compounded peptide off-label, this generates no registry entry, no protocol review, and no systematic adverse event collection unless the clinic participates in an IRB-approved study. The absence of trial entries for BPC-157 in humans does not mean it is not being administered to humans; it means that administration is not being studied in a controlled, registered, or reportable way.
Purity and identity of tested compound vs. sold compound. Trials registered in ClinicalTrials.gov specify the investigational product by manufacturer and batch. The peptide sold by a research chemical supplier or compounded by a pharmacy is not the same compound tested in any registered trial, even if the name matches. COA (certificate of analysis) from an independent ISO-accredited laboratory is the only way to verify the identity and purity of a specific lot. Look for HPLC purity of at minimum 98%, confirmed molecular weight by mass spectrometry, and absence of endotoxin testing results that confirm the batch passed LAL (limulus amebocyte lysate) testing.
Oral bioavailability is almost never the route tested. Most peptide RCTs use subcutaneous, intravenous, or intranasal administration. Oral peptide products have additional peptide hydrolysis and gut permeability problems that are compound-specific. A positive trial result in a subcutaneous format does not transfer to an oral format without dedicated bioavailability data.
Head-to-Head: Heavily Trialed Peptides vs. Wellness-Market Peptides
| Factor | Semaglutide (GLP-1) | Teriparatide (PTH analog) | BPC-157 | Ipamorelin |
|---|---|---|---|---|
| Completed Phase III RCTs | 10+ (SUSTAIN, STEP series) | 5+ (FORTEO program) | 0 | 0 |
| FDA approval status | Approved (T2D, obesity) | Approved (osteoporosis) | Not approved | Not approved |
| Human PK data available | Extensive, published | Extensive, published | None in major registries | Limited, small studies |
| Administration route studied | SubQ, oral (Rybelsus) | SubQ injection | Rodent (oral/IP) | SubQ in small human studies |
| Long-term safety data | Yes (multi-year CV trials) | Yes (2-year fracture trials) | No | No |
| Where peptide loses | Cost, GI side effects, injection | Cost, injection, duration limits | No human evidence at all | No efficacy RCT data |
How to Read a Trial Record: Operational Label Literacy
When you open any record in ClinicalTrials.gov, these five fields determine its evidentiary weight:
- Primary Outcome Measure and its timeframe. A validated scale (HbA1c, WOMAC score, fracture rate) carries more weight than an unvalidated surrogate. Check whether the timeframe is long enough to see a clinically relevant effect.
- Estimated vs. Actual Enrollment. A trial that enrolled 40 of a planned 200 subjects and was terminated has a drastically different reliability profile than one that reached its target. Termination reason (listed under "Why Stopped") is often the most informative field on the page.
- Sponsor type. Industry-only sponsorship with no academic co-investigator increases the chance that results will be selectively reported. NIH or academic co-sponsorship does not eliminate bias but lowers it.
- Results Posted. If the trial is listed as Completed but no results are posted and no linked publication appears in PubMed, treat the trial as producing unknown results, not positive ones.
- Blinding and randomization. Open-label Phase I dose-escalation trials are not evidence of efficacy. Look for "Randomized" under Study Design and "Double Blind" under Masking for efficacy claims to hold weight.
FAQ
What is the best clinical trial peptides database to search?
ClinicalTrials.gov is the largest single registry with over 500,000 registered studies as of 2025, and it covers the most therapeutic peptides by volume. For global coverage, cross-reference with the WHO ICTRP, which aggregates records from 17 primary registries. Neither source captures unpublished or proprietary peptide research.
How do I search ClinicalTrials.gov for a specific peptide?
Use the advanced search at clinicaltrials.gov/search. Enter the peptide's INN or its chemical name in the Intervention field. Filter by Study Type (Interventional), Phase, and Status (Completed or Active). Export results as JSON or CSV for bulk analysis. The MeSH term field is unreliable for peptides; free-text search returns more results.
What peptides have the most completed human RCTs?
GLP-1 receptor agonists (semaglutide, liraglutide), insulin analogs, oxytocin, and parathyroid hormone analogs (teriparatide) have the largest completed RCT bases. Research peptides popular in wellness contexts, such as BPC-157 or TB-500, have few or no completed human RCTs registered in any major database as of mid-2025.
Does ClinicalTrials.gov registration prove a peptide is safe or effective?
No. Registration means a sponsor filed paperwork before starting a study. It does not indicate peer review of the protocol, adequate statistical power, absence of conflicts of interest, or that the trial was ever completed. Always verify whether results have been posted or published in a peer-reviewed journal.
What does Phase I, II, or III mean for a peptide trial?
Phase I tests safety and dosing in a small group, typically 20 to 100 subjects, with no efficacy conclusion. Phase II adds preliminary efficacy signals in a larger cohort, typically 100 to 300 subjects. Phase III is a large confirmatory RCT, typically 300 to several thousand subjects, designed to prove efficacy and characterize the safety profile well enough for regulatory approval.
Why are so many peptide trials never completed or published?
Publication bias, commercial termination, and regulatory attrition account for most gaps. Research has consistently shown that a substantial share of registered trials across drug classes do not post results within 24 months of completion, and the rate is particularly low for trials with unfavorable findings. Anderson et al. (NEJM, 2015) documented this compliance gap specifically for ClinicalTrials.gov. Peptides with no commercial sponsor are especially prone to abandonment after Phase I or II.
How do I find peptide trials outside the US?
Use the WHO ICTRP search portal at trialsearch.who.int, which aggregates records from registries including EudraCT (EU), ISRCTN (UK), ANZCTR (Australia and NZ), and others. The EU Clinical Trials Register at clinicaltrialsregister.eu provides detailed protocol-level data for European trials.
Can I find peptide bioavailability or pharmacokinetic data in trial databases?
Phase I trial records sometimes include pharmacokinetic endpoints (Cmax, Tmax, half-life, bioavailability), but this data is usually in the posted results or the linked publication, not the registry summary. Search PubMed in parallel using the NCT number or the peptide name plus "pharmacokinetics" to retrieve full PK tables.
What is the difference between a peptide listed in ClinicalTrials.gov and an FDA-approved peptide drug?
FDA approval requires successful Phase III data, an NDA or BLA submission, and FDA review. A ClinicalTrials.gov listing only requires sponsor registration before enrollment. Most peptides in early-phase trials never reach approval. The FDA's Drugs@FDA database and the Purple Book list only approved products.
Do research peptides like BPC-157 or Ipamorelin appear in any clinical trial database?
As of mid-2025, BPC-157 and Ipamorelin have no completed Phase II or III human RCTs registered in ClinicalTrials.gov or the WHO ICTRP. Some animal and in vitro mechanistic studies exist in PubMed, but these do not constitute clinical trial database entries and do not establish human efficacy or safety profiles.
How do I read a trial's primary outcome to judge real-world relevance?
Check whether the primary outcome is a validated clinical endpoint (mortality, hospitalization, validated symptom scale) or a surrogate biomarker (a blood level, an imaging finding). Surrogate endpoints can generate positive trial results that do not translate to patient benefit. The FDA's guidance on surrogate endpoints distinguishes "reasonably likely" surrogates from validated ones.
Sources
- U.S. National Library of Medicine. ClinicalTrials.gov. https://clinicaltrials.gov. Accessed May 2026.
- World Health Organization. International Clinical Trials Registry Platform (ICTRP). https://trialsearch.who.int. Accessed May 2026.
- European Medicines Agency. EU Clinical Trials Register / CTIS. https://clinicaltrialsregister.eu. Accessed May 2026.
- Anderson ML, Chiswell K, Peterson ED, Tasneem A, Topping J, Califf RM. "Compliance with Results Reporting at ClinicalTrials.gov." New England Journal of Medicine. 2015;372(11):1031-1039.
- U.S. Food and Drug Administration. Drugs@FDA: FDA-Approved Drugs. https://www.accessdata.fda.gov/scripts/cder/daf/. Accessed May 2026.
- U.S. Food and Drug Administration. Guidance for Industry: Surrogate Endpoint Resources for Drug and Biologic Development. FDA, 2018.
- ISRCTN Registry. https://www.isrctn.com. Accessed May 2026.
- Marso SP, Daniels GH, Brown-Frandsen K, et al. "Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes." NEJM. 2016;375:311-322. (LEADER trial, GLP-1 agonist Phase III example.)
- Neer RM, Arnaud CD, Zanchetta JR, et al. "Effect of Parathyroid Hormone on Fractures and Bone Mineral Density in Postmenopausal Women with Osteoporosis." NEJM. 2001;344:1434-1441. (Teriparatide pivotal Phase III trial.)
- Food and Drug Administration Amendments Act (FDAAA) 801, 2007. Registration and results reporting requirements for applicable clinical trials.
Footer Disclaimers
Platform: FormBlends is an informational and formulation reference platform. Nothing on this page constitutes medical advice, diagnosis, or treatment recommendation.
Research Compound Notice: Peptides described on this page that lack FDA approval are research compounds. They are not approved for human therapeutic use and are not available as FDA-regulated medications absent a valid prescription for a compounded preparation where legally permitted.
Results Disclaimer: Database search results, trial counts, and registration statuses change continuously. Figures cited reflect searches conducted through May 2025 to May 2026. Always conduct a current search before citing any statistic from this page.
Trademark Notice: ClinicalTrials.gov is a service of the U.S. National Library of Medicine. SUSTAIN and STEP are trial program names associated with Novo Nordisk. FORTEO is a registered trademark of Eli Lilly and Company. FormBlends has no affiliation with any of these organizations.