How we
grade evidence.

We grade peptide × outcome pairs, not molecules. A peptide can hold an A grade for one studied use and a D for another. The grade attaches to a specific clinical claim, not to the chemical itself.

An outcome appears on a peptide page if it has been the subject of at least one peer-reviewed publication indexed in PubMed, Embase, or a comparable scientific database. We do not grade outcomes that exist only in marketing copy.

Every grade is a roll-up of six weighted sub-scores, each rated 1–5 with a written justification visible on the page.

• Mechanism understood — Do we know how the molecule produces the claimed effect at a molecular and physiological level?
• Human studies (count + quality) — How many controlled studies in humans exist, and what are they powered for?
• Effect vs placebo — Among trials with a placebo arm, how big and consistent is the placebo-adjusted effect?
• Long-term safety data — What is the longest published exposure window in humans?
• Side effect profile — What adverse events have been reported, at what rates, and how serious?
• Regulatory status — Has it been reviewed by FDA, EMA, or another major agency? Is it banned by sport governing bodies?

The first three sub-scores carry more weight in the roll-up. Efficacy and mechanism are what the grade is fundamentally about. Safety is necessary but not sufficient — a perfectly safe molecule with no demonstrable effect still earns a low grade.

We weight evidence in the following descending order of credibility:

1. Multiple replicated, well-powered Phase 3 RCTs in the target population, published in major peer-reviewed journals.
2. A single well-powered Phase 3 RCT with consistent Phase 2 supporting evidence.
3. Multiple Phase 2 RCTs converging on a finding.
4. A single Phase 2 RCT or a Phase 3 in a non-target population.
5. Open-label or single-arm human trials, case series, and pilot studies.
6. Animal models, in vitro, and computational studies.

Replication matters. A single-lab finding — even a strong one — counts for less than two independent labs producing consistent results.

Peptigrade is funded by member subscriptions and institutional licenses. We do not sell peptides. We do not accept industry sponsorships. We do not run display advertising. We do not earn affiliate commissions on peptide vendors.

The editorial board is still being seated. Board members’ names, credentials, and any commercial affiliations will be published on the About page as each seat is filled. No advisor with an undisclosed financial relationship to a peptide vendor will review grades for that vendor’s products.

Each peptide page may include a single “Where to research further” section linking to a supplier we track. Inclusion of a supplier requires:

• Batch-level certificates of analysis (HPLC purity, mass spec)
• Documented manufacturing facility and quality program
• Transparent country of origin
• Clear research-use-only labeling

Listing is editorial, not paid. Suppliers do not pay to appear here and cannot influence which peptide pages they are listed on. We disclose any commercial relationship with a listed supplier on the relevant page.

Each peptide page shows its last-updated date. The canonical, per-trigger SLAs — same-day, 7-day, 30-day, quarterly, annual — are defined in the Reassessment triggers section of the internal grading-and-reassessment protocol. The short version:

• Same day when an FDA action, WADA listing change, retraction, or major safety signal is announced.
• Within 7 days when a cited paper is flagged on PubPeer or a reader-submitted evidence challenge is received.
• Within 30 days of any new RCT, systematic review, or meta-analysis appearing in PubMed for that peptide × outcome.
• Quarterly for housekeeping (links, regulatory status, wording).
• Annual review even if no trigger has fired.

Errors of fact are corrected as soon as we are made aware. Corrections are appended to the page with a date and a short note describing what was changed. Substantial grade changes (a letter shift up or down) are explained in writing.

To report a factual error or contest a grade, write to corrections@peptigrade.io with citations.

The target editorial process is: a staff editor drafts the page from primary literature, a second editor reviews it against the rubric, and — where the relevant advisor seat is filled — a clinical advisor with subspecialty expertise audits grade-affecting claims before publication.

Until the advisor board is fully seated, pages in specialties without a seated advisor are reviewed by the Editorial Team only and noted as such. Blog posts and methodology essays follow the same pattern.