A clearer way to read the evidence.
Five editorial classifications, applied to a specific claim, outcome, and population.
- 01
Strong Evidence
Substantial, high-quality human evidence supports a clearly defined conclusion for the specified outcome and population.
- 02
Moderate Evidence
Meaningful human evidence supports a conclusion, but an important uncertainty remains.
- 03
Early Human Evidence
Research in people addresses the claim, but it cannot yet support a dependable clinical conclusion.
- 04
Preclinical Evidence
Relevant findings come from animal, cell, laboratory or other nonclinical models, without adequate human evidence for the claim.
- 05
Insufficient Evidence
Reliable, relevant evidence is too limited or too compromised to draw a meaningful conclusion about the claim.
Evidence and approval answer different questions. A grade describes the research supporting a claim. Approval applies to a particular medicine, use, and jurisdiction. An unassessed claim remains review pending.
Research is a pathway, not a promise.
Inside Peptides distinguishes observations in a model from outcomes measured in people. Preclinical findings can motivate human research; they cannot replace it. [1][2]
- 01
In vitro
Cells, tissues or laboratory systems.
- 02
Animal / preclinical
Biology and safety questions in nonhuman models.
- 03
Early human
Initial research in people.
- 04
Controlled human trials
Compare outcomes between study groups.
- 05
Multiple high-quality human studies
Assess consistency and applicability across studies.
- 06
Regulatory evaluation
Evaluate a specific medicine and use, where applicable.
Start with the right question.
Human clinical evidence
Ask who was studied, what was measured and whether there was a credible comparison. Human research ranges from early exploratory studies to multicenter trials. [4]
Explore human research →Preclinical evidence
Laboratory and animal findings help explore biological mechanisms. A model may not reproduce the complexity of human disease. [5]
Review preclinical peptides →Clinical trials
A registry describes a study; completed results answer a research question. Listing on ClinicalTrials.gov is not government approval of a treatment. [6]
Check trial registries →Regulatory evidence
Regulators evaluate medicine applications, not online popularity. Authorisation has a product and use-specific scope. [7][8]
View approved medicines →Experimental classifications
An investigational compound or use is being studied. Approved medicines can also be investigated for new uses; record authorization separately from research stage. [9][10]
Understand experimental status →Peptide research database
Search a selected index of published clinical trials and nonclinical experiments, with direct citation links and study-specific limitations.
Search research database →Look beyond the study label.
A trial phase or publication count is only a starting point. Confidence depends on the quality and relevance of the findings.
How we assess a claimStudy design
Was there a credible comparison, and how were participants assigned?
Relevant outcomes
Was a meaningful outcome measured in the people the claim concerns?
Consistency & precision
Do findings agree, and how much uncertainty surrounds the estimate?
Transparent reporting
Can the methods, results, limitations, and funding be traced?
Popular doesn’t mean proven.
Search volume, social-media discussion, influencer attention, clinic marketing and anecdotes are not inputs to our evidence classifications.
Our editorial rule is to follow the studies and their limitations. A convincing story cannot take the place of a credible comparison or a relevant measured outcome. [4][10]
See how this changes our wording →Go directly to the source.
These resources answer different questions. External websites are marked ↗.
PubMed (external website)
Find biomedical papers and abstracts. Read the study design and full text when available, not just the headline.
ClinicalTrials.gov (external website)
Look up study protocols, recruitment status and posted results. A registration is not proof that a treatment works.
Drugs@FDA (external website)
Check U.S. drug approvals, official labeling and FDA review documents. Search by ingredient, product or application number.
FDA Human Drug Compounding (external website)
Read official compounding policies and risk information. Compounding and product approval are different.
PubChem (external website)
Explore chemical identity, structures and linked records. Molecular information alone does not establish clinical benefit.
WADA Prohibited List (external website)
Check the applicable list and effective year for sport restrictions. Anti-doping status is not a medicine approval or evidence grade.
EMA medicines (external website)
Find European public assessment reports and product information for medicines evaluated by EMA.
Research reading guides
- Orforglipron, Retatrutide and CagriSema: Where the Next Weight-Loss Drugs Stand
- GLP-1 Drugs Beyond Weight Loss: What’s Proven, Promising or Failed
- How to Read a Clinical Trial Results Table
- How to Check Whether a Peptide Study Has Been Peer Reviewed
- How to Evaluate a Peptide Systematic Review or Meta-Analysis
References
Official source destinations checked 2026-10-06. External links are marked ↗.
- FDA: Step 2: Preclinical research (external website)
Laboratory and nonclinical testing; evaluation before testing in people.
Back to citation ↑ - FDA: Step 3: Clinical research (external website)
Human study design, trial phases and investigational research.
Back to citation ↑ - Cochrane Handbook, chapter 10: Meta-analysis (external website)
Evidence synthesis, heterogeneity and limitations of pooling.
Back to citation ↑ - Cochrane Handbook, chapter 8: Risk of bias in randomized trials (external website)
Randomization, allocation concealment, missing outcomes and selective reporting.
Back to citation ↑ - NIH / NIEHS: Alternatives to animal testing (external website)
Research models include cells, animals and computer models; human relevance can be uncertain.
Back to citation ↑ - ClinicalTrials.gov: Official disclaimer (external website)
Registration is not government endorsement; sponsors supply study records.
Back to citation ↑ - FDA: Step 4: Drug review (external website)
FDA reviews submitted evidence and labeling in approval decisions.
Back to citation ↑ - EMA: Authorisation of medicines (external website)
EMA evaluates centrally authorised medicines; the European Commission grants authorisation.
Back to citation ↑ - Cochrane Handbook, chapter 14: Grading certainty of evidence (external website)
Outcome-specific certainty, five uncertainty domains; formal GRADE has four levels.
Back to citation ↑ - Cochrane Handbook, chapter 15: Interpreting results (external website)
Effect size, confidence intervals, clinical relevance and applicability.
Back to citation ↑