# Peptide R Lab — Recovery & Tissue Repair research peptides > Peptide R Lab is a lab-notebook style research digest on four Recovery & Tissue Repair research peptides: BPC-157, KLOW, KPV, and TB-500 — mechanism, evidence, and cited cautions, with no products and no medical advice. A briskly clinical read-through of BPC-157, KLOW, KPV, and TB-500 — what each is shown to do, what is reported anecdotally, and what remains unverified in humans. ## The short version Peptide R Lab reads like a lab notebook, not a marketing page. It tracks four research peptides that keep coming up in conversations about **recovery and tissue repair**: BPC-157, KLOW, KPV, and TB-500. Each is a short chain of amino acids — the same building blocks that make up every protein in the body, just much smaller — that laboratory researchers have studied for how the body rebuilds itself after injury: the gut lining, tendons and ligaments, skin, and blood vessels. None of these four is an approved medicine. Three of them — BPC-157, KPV, and TB-500 — are individual research peptides, mostly tested in cells and animals, with only a couple of small human safety pilots between them. The fourth, KLOW, is not a single peptide at all — it is a pre-mixed research vial containing the other three plus a fourth compound, GHK-Cu, sold as a combination product that has never itself been tested in any controlled study. This notebook cites its sources, flags what is anecdotal, and never recommends a human dose. ## How this notebook is organized This site is organized as **a lab-notebook tour of the tissue-repair peptides** — four entries, each read in the same order: what it is, what mechanism researchers propose, what the primary literature actually reports, what people using it for research purposes say anecdotally, and what cautions the cited evidence supports. [TB-500](/tb-500) leads the notebook, because its parent molecule (full-length thymosin beta-4) carries the deepest human trial record of the four, even though the fragment sold as "TB-500" itself has not been tested in a completed human trial. [BPC-157](/bpc-157) follows as the angiogenesis and gut-mucosa entry. [KLOW](/klow) is the combination-product entry — a chart note more than a peptide summary, since it packages BPC-157 and TB-500 together with two additional compounds. [KPV](/kpv) closes the tour as the anti-inflammatory tripeptide with the thinnest human evidence base of the four. A [side-by-side comparison](/compare) lines all four up on the same dimensions. ## What are research peptides? Peptides are short chains of amino acids, the molecular building blocks that also make up full proteins — just far smaller, usually somewhere between three and forty amino acids long. The four entries in this notebook are described in the literature as **research peptides**: laboratory compounds studied mainly in cell cultures and animal models for their effects on wound healing, connective-tissue repair, gut-lining integrity, and blood-vessel growth (angiogenesis). None of the four is an FDA-approved drug. They are sold by research-chemical suppliers labeled for laboratory use only, not for human consumption, and none carries an established human dose. Where this notebook reports a dose, it reports the exact amount used in a specific cited study, in a specific species, never as a recommendation. Human evidence for this group ranges from thin (BPC-157: one two-person IV safety pilot [1]) to essentially nonexistent (KPV: zero published human trials) to borrowed from a related but distinct molecule (TB-500: most human data describe the full-length parent protein studied in a Phase 1 trial [16], not the fragment sold under that name). ## Reading the evidence honestly Every claim on this notebook traces to a numbered source on the shared [references page](/references) — PubMed-indexed studies, structural biology papers, and one Phase 1 human trial, cited by bracketed number throughout. Where an entry's evidence is preclinical only, the notebook says so directly rather than implying otherwise. Where community-reported effects appear, they are labeled anecdotal and kept separate from anything a controlled study measured. Two patterns recur across all four entries. First, angiogenesis (new blood-vessel growth) shows up as a proposed mechanism for BPC-157, TB-500, and by extension KLOW, which is why a theoretical cancer caution appears on each of those pages. Second, the human evidence gap is real: across all four compounds combined, the entire published human-trial record amounts to a two-person BPC-157 safety pilot [1] and a 40-person thymosin beta-4 Phase 1 trial [16] — nothing more. The [comparison page](/compare) puts these gaps side by side. --- Peptide R Lab keeps a citation-anchored bench log on tissue-repair peptides — a research chart, not a treatment plan.