---
title: "How We Grade Peptide Evidence: A, B, C, D and U"
description: "One published scale for every claim: Approved, then A to D by the kind of human, animal or cell studies that exist, and U for user reports only. Per claim, never per peptide."
canonical: https://plainlygraded.com/evidence-grading/
breadcrumb: "Home > How we grade evidence"
publisher: Plainly Graded
policy: "No dosing, no sourcing, no vendor links. Every claim cites a public source."
---

> We collect and compare information from public, cited sources. We cannot guarantee that it is complete, current or correct. This is not medical advice. Only a doctor can prescribe, and a doctor should confirm anything you read here before you act on it.

# How we grade evidence

- ApprovedAn FDA-approved drug, for the approved use only. We name the approval.

**Evidence grade A** Consistent randomized controlled trials in people, for this use.

**Evidence grade B** At least one adequate human trial, or mixed trial results.

**Evidence grade C** Small human pilots, case series or uncontrolled reports only.

**Evidence grade D** Animal or cell studies only.

**Evidence grade U** User reports only, or no published study at all.

## How grades are applied

-   **Per claim, not per peptide.** A peptide can be B for one use and D for another.
-   **A blend is graded as a blend.** Good evidence for each ingredient does not transfer to the mix.
-   **Every grade links to the studies behind it,** and changes to a grade are logged in the page's grade history.
-   **Animal and cell results are never written as effects in people.** We write "in rats" rather than "it heals".

---

We collect and compare information from public, cited sources. We cannot guarantee that it is complete, current or correct. This is not medical advice. Only a doctor can prescribe, and a doctor should confirm anything you read here before you act on it.

Canonical page: https://plainlygraded.com/evidence-grading/