RESEARCH PEPTIDE FUNDAMENTALS / COLOPHON
About This Desk
A citation-anchored survey of five research peptides sitting at very different rungs of the evidence ladder. Nothing sold here, nothing prescribed, no clinic behind it.
What Research Peptides US is
Research Peptides US is a plain survey of five compounds that dominate US research-peptide conversation for different reasons: BPC-157 (tissue repair), KPV (gut inflammation), NAD+ (cellular energy and longevity), retatrutide (investigational metabolic triple-agonist), and tirzepatide (approved dual-agonist, the lead compound here). The organizing idea is blunt by design: sort what the published literature actually shows from what a supplier's landing page or a forum thread claims.
These five sit at genuinely different points on the same evidence ladder, and that's precisely why they're grouped together. Reading them side by side — rather than one at a time on five different vendor sites — makes the gap between hype and evidence maturity impossible to miss. Tirzepatide has a full FDA-approved, multi-trial record. Retatrutide has strong Phase 2 numbers and zero approvals. NAD+ has solid human dosing trials but unproven downstream benefit. BPC-157 has one two-person human safety pilot on top of decades of rat data. KPV has no human trial data whatsoever. The survey holds all five to the same editorial discipline, whatever stage they're actually at.
How the survey is built
Three rules run the survey.
First, every specific claim carries a numbered citation. Percentages, trial sizes, half-lives, and dose figures all trace to a peer-reviewed article, a registered clinical-trial publication, or a peer-reviewed clinical-reference chapter, gathered on the references page with DOIs and PubMed links where available.
Second, evidence is stated at the strength it actually has. A finding from a 338-person Phase 2 trial is called exactly that — not stretched into a universal claim. A rat study stays a rat study. Community-reported effects are marked anecdotal and never pinned to a specific dose.
Third, the five compound pages cross-reference each other. Because the same threads recur — receptor mechanisms, GI side effects, gray-market sourcing risk, the animal-to-human gap — the pages link to one another and to the comparison page, so a reader can trace a theme across the whole survey instead of reading one compound alone.
What the survey is not
Research Peptides US runs no pharmacy, clinic, telehealth platform, or storefront. It sells, sources, and brokers none of the compounds discussed here, and holds no affiliate tie to any research-chemical supplier, drug company, or telehealth provider. It diagnoses nothing, prescribes nothing, and recommends no dose, schedule, or route of administration for anyone.
Tirzepatide is an approved prescription medicine available only through a licensed provider. Retatrutide is investigational and legally available only inside registered clinical trials. BPC-157 and KPV are unregulated research chemicals with no approved human use. NAD+ and its precursors are supplements or compounded products, not FDA-approved drugs. Readers seeking clinical guidance should consult a licensed healthcare provider. Notes on citation corrections or newly published research can go through the contact page — but the survey cannot answer requests for medical advice.