How we grade evidence

This page explains the labels used across PeptideSciences101. The framework is designed to separate validated clinical evidence from preclinical, mechanistic, and anecdotal information. It is editorial methodology, not medical advice.

Every peptide profile is described along four axes: its regulatory status, an evidence grade, the level of human evidence available, and a safety-visibility label. Each axis has a fixed, plain-language vocabulary so that the same words mean the same thing on every page, in comparisons, and in search.

Evidence grades

The evidence grade summarizes the strength and type of support for a compound, from FDA-approved human use (Grade A) down to insufficient or conflicting evidence (Grade X).

Grade	Meaning	What it does not imply
Grade A	Supported by FDA approval or clinical-practice guidelines for human use.	Applies to specific approved indications; does not generalize to off-label or research uses.
Grade B	Human clinical-trial evidence exists, but the compound is not FDA-approved for this use.	Clinical-trial evidence is not the same as regulatory approval or established practice.
Grade C	Evidence is mainly animal or preclinical, with limited or no human trials.	Preclinical and limited human data do not establish safety or efficacy in people.
Grade D	Support is mechanistic, theoretical, or speculative rather than outcome-based.	Mechanistic plausibility is not evidence of a real-world clinical effect.
Grade X	Evidence is insufficient, conflicting, or unreliable to characterize this compound.	There is not enough trustworthy evidence to support any conclusion.

Regulatory status

Regulatory status records how a compound is treated by regulators — most importantly, whether it is FDA-approved. It is independent of the evidence grade: a compound can have human-trial evidence and still not be approved.

Status	Meaning
FDA Approved	Approved by the U.S. Food and Drug Administration for one or more labeled indications.
Approved (ex-U.S.)	Approved by a regulator outside the United States; not FDA-approved.
Investigational	Under active clinical investigation; not yet approved for marketing.
Research-stage	Studied primarily in laboratory or preclinical settings; not approved for human therapeutic use.
Preclinical	Evidence is limited to cell or animal models; no meaningful human data.
Not FDA-approved	Not approved by the FDA for any indication. Regulatory handling varies.
Withdrawn	Previously available but withdrawn or discontinued from the market.
Status unknown	Regulatory status has not been determined or confirmed for this profile.

Human evidence level

Human evidence is tracked separately from animal and mechanistic data. Where a precise clinical-trial phase is not documented, the most conservative honest label is used rather than an assumed phase.

Level	Meaning
Approved clinical use	Used clinically under regulatory approval.
Phase 3	Evaluated in large confirmatory human trials.
Phase 2	Evaluated for efficacy and dosing in human trials.
Phase 1	Early human testing focused on safety and tolerability.
Observational human data	Human data from observational, non-randomized studies.
Case reports	Limited human evidence from individual case reports.
No meaningful human evidence	No reliable human evidence is currently catalogued.
Unknown	Human-evidence level has not been determined.

Safety visibility

Safety visibility describes how much is known about a compound’s safety — not a verdict that it is safe. Research-stage compounds carry a research-only safety profile because their safety has not been characterized for approved human use.

Label	Meaning
Established label safety profile	A characterized safety profile exists in approved prescribing information.
Known serious risks	Documented serious risks or warnings. Review primary sources and labeling.
Limited human safety data	Some human safety data exists, but it is limited or preliminary.
Research-only safety profile	Safety information comes from research settings, not approved human use.
Insufficient safety data	There is not enough data to characterize safety.

Citation source types

Citations are labeled by source type so readers can weigh them. Primary regulatory and clinical sources rank above secondary summaries and manufacturer communications.

Source type	Meaning
FDA label	Official FDA-approved prescribing information.
DailyMed	NIH DailyMed structured product labeling.
ClinicalTrials.gov	Registered clinical-trial record.
PubMed — human study	Peer-reviewed human study indexed in PubMed.
PubMed — animal study	Peer-reviewed animal/preclinical study indexed in PubMed.
Clinical guideline	Professional or regulatory clinical-practice guideline.
Regulatory agency notice	Notice or communication from a regulatory agency.
Conference abstract	Abstract presented at a scientific conference (not peer-reviewed in full).
Manufacturer press release	Manufacturer or sponsor communication; not independent evidence.
Secondary source	Review article, textbook, or other secondary summary.
Unknown	Source type has not been classified.

Limitations

Grades and labels are derived from the best information currently catalogued and are refined as profiles are reviewed. They summarize available evidence; they do not establish safety, efficacy, dosing, or medical use. Research-stage profiles are not treatment recommendations. Nothing on this site is a substitute for advice from a licensed healthcare professional.