Research
Peptide Evidence Index 2026
A standardised comparison of the human evidence, clinical-trial status and regulatory status of every compound in the PeptideIndex database.
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What the Peptide Evidence Index is
The Peptide Evidence Index is a structured synthesis of publicly available evidence for the 20 compounds in the PeptideIndex peptide research database. It is not original clinical research and it reports no new data. Its value is the standardised comparison: the same questions asked of every compound, so peptide evidence grades, human studies, clinical trials and regulatory status can be read side by side rather than assembled from scattered sources.
We built it because peptide clinical evidence is unevenly distributed. A few compounds are approved medicines backed by large randomised trials; most rest on animal or mechanistic work, and some have no meaningful direct human evidence at all. Popularity is a poor proxy for evidence, and marketing rarely makes the distinction.
An evidence grade on this site summarises how strong and how directly applicable the body of published research is for a compound. Human randomised evidence carries more weight than observational human data, which carries more weight than animal or in-vitro findings, because only controlled human research can show that an effect seen in a dish or a rodent translates to people at a realistic dose.
Evidence strength is not safety, and it is not suitability for any individual. A well-studied compound can still be unsafe for a given person, and a poorly studied one is not thereby safe — it is simply unknown. Nothing here is medical advice.
Summary statistics
- Compounds indexed
- 20
- Strong evidence grade
- 5
- Moderate evidence grade
- 4
- Emerging evidence grade
- 5
- Limited evidence grade
- 6
- With controlled human trial evidence
- 9
- Approved medicine for at least one indication
- 6
- Primary source links catalogued
- 27
The index
Category
Evidence grade
Human evidence
| Peptide | Category | Evidence grade | Human evidence | Clinical-trial status | Regulatory status | Primary sources |
|---|---|---|---|---|---|---|
| BPC-157Evidence review | Recovery & repair | Emerging | Limited human studies — a registered phase 1 safety/pharmacokinetics study in healthy volunteers; efficacy evidence is predominantly animal | Registered phase 1 trial; no completed positive efficacy programme identified | Not approved as a medicine; research-compound status in most jurisdictions |
|
| TB-500Evidence review | Recovery & repair | Emerging | No direct human trials of marketed TB-500 identified; randomised human trials exist for thymosin beta-4 formulations, which are a different product | Human trials are of topical thymosin beta-4 (RGN-259), not TB-500 | Not approved for human use; sold for research purposes only |
|
| CJC-1295Evidence review | Growth hormone | Moderate | Early human evidence on GH and IGF-1 secretion; clinical-outcome data limited | Early-phase human research; no current approval programme identified | Not approved as a medicine; prohibited in sport |
|
| IpamorelinEvidence review | Growth hormone | Moderate | Early human evidence on GH secretion; no established clinical-outcome evidence | Early-phase human research; no approved indication | Not approved as a medicine; prohibited in sport |
|
| TesamorelinEvidence review | Growth hormone | Strong | Multiple controlled human trials supporting a specific approved indication | Approved medicine with a completed clinical-trial programme | Approved for a specific medical indication; other uses are off-label |
|
| SemaglutideEvidence review | Metabolic | Strong | Multiple large controlled human trials | Approved medicine with an extensive phase 3 programme | Approved, prescription-only medicine for specific indications |
|
| TirzepatideEvidence review | Metabolic | Strong | Multiple large controlled human trials | Approved medicine with an extensive phase 3 programme | Approved, prescription-only medicine for specific indications |
|
| RetatrutideEvidence review | Metabolic | Strong | Peer-reviewed randomised phase 2 trials; phase 3 outcomes so far company-reported with peer-reviewed publication pending | Phase 3 programme ongoing; phase 2 completed and published | Investigational; not approved as a medicine |
|
| MOTS-cEvidence review | Metabolic | Emerging | Human data largely observational (endogenous levels); interventional evidence is animal, so this is not human efficacy evidence | No substantial direct clinical-trial programme identified | Research compound; not approved as a medicine |
|
| AOD-9604 | Metabolic | Limited | Limited human evidence; no established clinical outcomes | Early-phase human research reported; no approved indication | Not approved as a medicine; permitted as a food additive in some jurisdictions |
|
| 5-Amino-1MQ | Metabolic | Limited | No meaningful direct human evidence identified | No substantial direct clinical-trial programme identified | Not an approved medicine or dietary supplement |
|
| EpitalonEvidence review | Longevity | Limited | Russian clinical reports have not been independently confirmed; no confirmatory controlled trials identified | No independently confirmed clinical-trial programme identified | Not approved outside Russia/CIS research contexts |
|
| SS-31Evidence review | Longevity | Moderate | Randomised phase 3 trial in primary mitochondrial myopathy (primary endpoints not met) — a disease population, not an ageing or lifespan outcome | Phase 3 completed; primary endpoints not met | Investigational; not approved for general use |
|
| NAD+Evidence review | Longevity | Emerging | Randomised human trials of NAD+ precursors with biomarker endpoints; no lifespan or clinical-outcome evidence | Human trials with biomarker endpoints; no approval programme for ageing | Not an approved medicine for ageing; compounded and sold in clinics |
|
| SemaxEvidence review | Cognitive | Limited | Human use is based largely on Russian clinical literature with limited international replication | No internationally replicated clinical-trial programme identified | Approved medicine in Russia; unapproved elsewhere |
|
| SelankEvidence review | Cognitive | Limited | Human use is based largely on Russian clinical literature with limited international replication | No internationally replicated clinical-trial programme identified | Registered in Russia; research-only status elsewhere |
|
| GHK-CuEvidence review | Skin & hair | Moderate | Limited human evidence for topical/cosmetic use; no trials of injectable use identified | No substantial clinical-trial programme identified for injectable use | Widely used as a cosmetic ingredient; injectable use is unapproved |
|
| Melanotan II | Skin & hair | Limited | Early human evidence only, alongside documented safety concerns | No approved clinical-development programme identified | Not approved anywhere; illegal to sell for human use in the UK, EU and US |
|
| PT-141 | Sexual health | Strong | Multiple controlled human trials supporting a specific approved indication | Approved medicine with a completed clinical-trial programme | Approved (Vyleesi) for premenopausal HSDD; other uses are off-label |
|
| Kisspeptin-10 | Sexual health | Emerging | Randomized controlled human study in healthy men showing endocrine activity; therapeutic efficacy for a clinical indication remains unestablished | Controlled human studies published; therapeutic clinical efficacy remains investigational | Research compound; not approved for human use |
|
How the Peptide Evidence Index works
The index applies the evidence hierarchy PeptideIndex already uses across the site, strongest first:
- Human randomised or controlled evidence
- Observational human evidence
- Animal research
- In-vitro and mechanistic evidence
- Anecdote and self-report
No new scoring system was created for this page. Grades are read directly from the existing compound profiles, and trial and regulatory descriptors state only what can be verified from catalogued sources. Where no verified primary source is yet catalogued, the row says so rather than implying completeness. Read the full editorial methodology. The index is a structured synthesis of the available evidence, not medical advice.
What the evidence grades mean
- Strong
- Consistent controlled human evidence, usually with an approved medicine behind it.
- Moderate
- Some human evidence, but limited in size, scope or outcome quality.
- Emerging
- Early or indirect human evidence; the bulk of the research is preclinical.
- Limited
- Little or no reliable human evidence identified for the compound itself.
Full definitions live in the editorial methodology.
Questions this dataset answers
Which peptides have the strongest human evidence?
5 compounds carry the site's highest existing grade: Tesamorelin, Semaglutide, Tirzepatide, Retatrutide, PT-141. That reflects controlled human trial programmes rather than any ranking created for this page. Retatrutide is included on published phase 2 evidence; its phase 3 outcomes are so far company-reported with peer-reviewed publication pending.
Which peptides have limited human evidence?
11 of 20 compounds rely predominantly on early-phase, indirect or preclinical research. TB-500 is a clear example: the randomised human trials in this area studied topical thymosin beta-4 formulations, not marketed TB-500, so they are not direct evidence for it.
Does an evidence grade mean a peptide is safe?
No. Evidence strength and safety are related but separate questions. A grade describes how well an effect has been studied, not whether a compound is safe for a particular person, dose, duration or combination.
Does regulatory approval mean every use is proven?
No. Approval applies to specific products, specific indications and specific jurisdictions. An approved peptide medicine used for an unapproved purpose is not covered by the evidence that secured that approval.
Do longevity peptides have human lifespan evidence?
Not in this dataset. Where human trials exist for longevity-associated compounds, they measure biomarkers, mitochondrial or metabolic outcomes, or disease endpoints. Those are not demonstrations of extended human lifespan.
Citing the Peptide Evidence Index
This page may be cited freely. Publisher: PeptideIndex. Year: 2026.
PeptideIndex. Peptide Evidence Index 2026. A structured comparison of the human, clinical and regulatory evidence across 20 peptide compounds. https://peptide-index.org/research/peptide-evidence-index
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