How REGEN Grades Peptide Evidence
Every compound in this library carries one letter. This is what the letter means, and what it deliberately refuses to take into account.
The principle
A grade here answers one question: how well has this been measured in humans? It does not answer whether the compound is effective, whether it is safe, or whether it is worth taking. Those are different questions, and conflating them is how reference sites end up ranking a rodent study alongside a phase 3 trial.
The result is that the grades often disagree with the popular ranking. BPC-157 is one of the most searched compounds in this field and grades a Cgrade because no completed randomised human trial exists for it. That is not a criticism of the compound. It is a description of the literature.
The six tiers
| Grade | What it requires | In this library |
|---|---|---|
| Sgrade Regulatory approval | Approved by the FDA or an equivalent regulator for a named indication, on the strength of phase 3 trials. Approval is a statement about a specific indication at a specific dose. It does not transfer to off-label use of the same molecule. | hCG (Human Chorionic Gonadotropin), Exenatide, Liraglutide |
| Agrade Randomised human trials | Multiple randomised, controlled human trials with consistent results, but no approval for the use described here. This is the strongest grade an unapproved compound can reach, and very few do. | Retatrutide, MK-677, Thymosin Alpha-1 |
| Bgrade Controlled human data | At least one randomised or well-controlled human trial, or a body of consistent controlled work in a related indication. Enough to say an effect has been measured in people, not enough to say how reliably it reproduces. | BPC-157 + TB-500 Blend, GLOW Blend, Tesamorelin + Ipamorelin Blend |
| Cgrade Uncontrolled human data | Small human pilots, open-label series, or case reports, usually alongside a substantial animal literature. Where most of the popular research peptides sit. A C is not a verdict that the compound fails, it is a statement that the trial to answer the question has not been run. | BPC-157, CJC-1295 (no-DAC) + Ipamorelin Blend, Ipamorelin |
| Dgrade Preclinical only | Animal or in-vitro work only, with no human data of any design. Mechanism can be well characterised at this grade. Dose translation from a rodent model is the part that does not carry over. | CJC-1295 (DAC), TB-500, AHK-Cu (Copper Tripeptide-3) |
| Fgrade No usable evidence | No published study of the compound in any model, or evidence that has been retracted or withdrawn. Includes compounds whose headline result was later retracted, which is worse than never having been studied. | Adamax, Dihexa, Follistatin-344 |
What a grade ignores
- Anecdote and community consensus. Both are useful signals about what to study. Neither is evidence of an effect.
- Mechanism plausibility. A convincing pathway is a reason to run a trial, not a substitute for one.
- Vendor claims and marketing copy. This library carries no affiliate offers and links to no sellers, which is why the grades can say what they say.
- Search volume. The most searched compounds in this field are frequently the least evidenced, and the ordering on our category pages puts grade ahead of popularity for exactly that reason.
When a grade changes
Grades move when the literature moves: a trial reads out, a compound is approved, a result is retracted. They do not move because a compound became popular. The library currently covers 54 compounds across 270 cited sources, and each compound page shows the date it was last reviewed alongside the sources it rests on.
Frequently asked questions
Does a low grade mean a peptide does not work?
No. The grade describes the quality of the evidence, not the size of the effect. A compound graded D may well do what people report; it means no human trial has been run to check. Popularity, anecdote, and mechanism plausibility do not move a grade.
Why is an FDA-approved drug graded higher than a well-studied research peptide?
Approval requires phase 3 trials powered for a defined endpoint, plus a regulator reviewing the full dataset including the failures. No amount of preclinical work substitutes for that, so approval is its own tier.
Do you grade a compound differently for different uses?
The headline grade reflects the strongest evidence for the use the compound is best known for. Where the evidence differs by claim, the evidence table on each compound page grades each claim separately.
Who writes and reviews these grades?
Grades are assigned by REGEN editorial from the published literature and re-checked when new trials appear. Every grade on a compound page links back to the sources it rests on, so the reasoning is auditable rather than asserted.