Peptide claims on social media, commercial sites, and even PubMed carry very different levels of support. The atlas uses a six-level grade — A, B, C, D, E, and X — applied to a precise claim rather than to the whole molecule. This post walks through each grade with real examples from the monographs.
The full system is documented in Evidence grading. If you are new to the atlas, start with How to read peptide evidence for the broader reading framework.
Grade A — established for a specific labeled use
A grade A claim is supported by current regulatory approval, adequate controlled trials, and post-market context. It is the highest confidence the atlas assigns, but it remains bounded by the label: the claim covers a defined product, population, indication, and jurisdiction.
The semaglutide monograph shows multiple grade A rows. Glycemic control in type 2 diabetes carries grade A based on the SUSTAIN program (>10,000 participants). Chronic weight management also carries grade A from the STEP program. Cardiovascular risk reduction — supported by SELECT (N=17,604) — is another A. In each case the grade reflects the exact claim, not a blanket endorsement of semaglutide for every purpose.
Grade B — moderate human evidence
Grade B means multiple controlled studies or a strong pivotal study exist, but the claim does not have current approval or still carries a material confirmation gap.
The retatrutide monograph illustrates B across the board. Chronic weight management is grade B from TRIUMPH-1 (28.3% mean weight loss at 80 weeks), glycemic control in type 2 diabetes is B from TRANSCEND-T2D-1, and knee osteoarthritis with obesity is B from TRIUMPH-4. All these claims are supported by Phase 3 data, but retatrutide has no marketing authorization identified in any major regulator database as of August 2026. Strong development-stage evidence and regulatory approval are different facts.
Semaglutide itself carries one grade B row: the MASH accelerated approval is graded B because confirmatory evidence is still required.
Grade C — preliminary human evidence
Grade C covers small, uncontrolled, early-phase, or surrogate-endpoint studies. Human observations exist, but they are insufficient for a confident conclusion about efficacy.
In the BPC-157 monograph, interstitial cystitis is graded C — supported by a single-arm pilot study (n=12) reporting 80–100% symptom resolution. The safety and pharmacokinetics row is also graded C, based on a Phase 1 infusion study (n=2). Neither row can support a claim of established efficacy.
Grade D — preclinical only
Grade D means in vitro or animal evidence without adequate human efficacy data. No controlled human trial directly tests the claim.
BPC-157's musculoskeletal healing claim is grade D — supported by only a retrospective, uncontrolled chart review (17 records, 12 BPC-157-only). Inflammatory bowel disease, wound healing, and other widely marketed uses are also grade D, relying entirely on animal models.
Grade E — anecdotal or marketing claim
Grade E covers testimonials, extrapolation, or marketer assertions that lack adequate scientific support. The atlas assigns E when a claim circulates widely but no verifiable human evidence directly supports it.
A claim becomes grade E not because it is disproven, but because the available evidence cannot justify a stronger conclusion. The distinction between D and E is whether human observation exists at all; between C and E is whether the human observation is structured enough to evaluate.
Grade X — evidence contradicts the claim
Grade X signals an affirmative conflict rather than mere absence of support. It applies when adequate evidence contradicts a claim, a development program failed, or the claim is inconsistent with the studied material. X is not a weaker version of E — it means the available evidence points against the claim. No monograph in the current catalog carries an X row, but the category exists precisely so the system can record negative findings without ambiguity.
The study-level fields that support each grade
The Evidence grading methodology defines the fields recorded for every study in the evidence table: population, comparator, sample size, route, duration, endpoint, result, and important limitations. Statistical significance is not treated as clinical importance, and biomarker changes are not silently converted into patient benefit.
Common bias checks applied during grading include: randomization and blinding status, attrition and selective reporting, multiplicity and post-hoc analyses, small-study and sponsor bias, short follow-up for chronic-benefit or safety claims, and the non-equivalence of the tested pharmaceutical product and marketed research material.
Reading grades together with status tables
A grade and a regulatory status answer different questions. Retatrutide's grade B claims reflect strong Phase 3 data; its status table says no marketing authorization was identified. BPC-157's grade D and C claims reflect limited human data; its status table records no FDA-approved or EMA-authorized product. WADA lists BPC-157 as prohibited under class S0, a fact that belongs in the status table rather than the evidence grade. The methodology page explains how the two dimensions work together.
Before treating any grade as a final verdict, identify the exact claim being graded, check whether the human evidence directly tests it, and verify the current regulatory status in the relevant jurisdiction. A lower grade is not proof that an effect is impossible. It says the available evidence cannot justify a stronger conclusion. Likewise, an A does not mean risk-free, appropriate for everyone, or established outside the labeled context.