Recovery ⏱ Half-life: Not established for the blend; rodent and dog work reports under 30 minutes for BPC-157 Experimental

KLOW

Vendor-coined trade name for a four-peptide blend; no official INN assigned

Updated July 24, 2026
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Evidence at a Glance

Regulatory statusExperimental
Unstudied fixed blend of GHK-Cu, BPC-157, TB-500 and KPV; sold research-use-only.
Human evidenceNone
Animal evidenceNone

KLOW is a fixed research-use-only blend of GHK-Cu, BPC-157, TB-500 and KPV that has never been tested as a combination in humans or animals, so its safety and efficacy are unknown.

What the research does not support

  • No study has ever tested this four-peptide combination in humans or animals, so its benefits are extrapolated, not demonstrated.
  • Its components BPC-157 and TB-500 are themselves unapproved and lack human efficacy data, so bundling them adds no proven benefit.
  • It is not an approved or clinically validated healing, recovery or anti-aging therapy.
  • Combining peptides does not guarantee additive effects and may alter absorption, stability or risk in unknown ways.
Half-Life
Not established for the blend; rodent and dog work reports under 30 minutes for BPC-157
Mol. Weight
Not applicable to a blend — components span 340.38 to approximately 4963 g/mol
Form
Lyophilized powder

What is KLOW?

KLOW is not a single compound. It is a trade name for a research blend of four peptides, sold most often as an 80 mg lyophilized vial divided roughly into 50 mg GHK-Cu, 10 mg BPC-157, 10 mg TB-500 and 10 mg KPV. That split is what suppliers market; no regulated or standardized composition exists, and ratios may differ by source. The name has no chemical or pharmacological standing, and appears to extend an earlier three-peptide blend by adding KPV. Being a mixture rather than a molecule, KLOW has no sequence and no molecular weight of its own.

The components are genuinely peptides but otherwise unrelated in origin, size and mechanism. GHK-Cu is the copper(II) complex of glycyl-histidyl-lysine (Gly-His-Lys), a sequence occurring endogenously in human plasma; the free tripeptide is 340.38 g/mol and the neutral 1:1 complex 401.91 g/mol, though quoted values are representation-dependent (~403.9 g/mol is common). BPC-157 is a synthetic 15-residue peptide, GEPPPGKPADDAGLV, 1419.5 g/mol, corresponding to the N-terminal region of body protection compound, a protein present in human gastric juice, first described by Sikiric and colleagues in 1993. No residue numbering is established in the primary literature, it shows no homology with known intestinal peptides, and no free BPC-157 fragment is known to occur naturally in humans. KPV is Lys-Pro-Val, 342.43 g/mol, the C-terminal tripeptide of alpha-melanocyte-stimulating hormone.

What “TB-500” actually refers to

FDA names the substance “Thymosin beta-4, fragment (LKKTETQ), also known as TB-500”: the synthetic acetylated heptapeptide Ac-LKKTETQ, about 889 g/mol, residues 17–23 of mature thymosin beta-4. In practice much of the research-supply market ships full-length thymosin beta-4, a 43-residue peptide of approximately 4963 g/mol, under the same label. These are chemically distinct molecules with different molar content per milligram, different pharmacokinetics and regulatory histories, and a vial labelled only “TB-500” does not disclose which is present — an ambiguity that carries into the blend.

The evidence base for the blend is empty: no published study has administered these four compounds together, and the rationale for combining them is mechanistic plausibility rather than tested effect. Regulatory status is frequently misstated: all four were previously in Category 2 of FDA’s interim bulk-substances policy, but on the listing current 22 April 2026 none remains there, each appearing instead under bulk substances nominated but withdrawn — withdrawn by the nominators, which is not approval or endorsement. None is approved for human use by FDA or any comparable regulator; these materials are handled as research chemicals for laboratory investigation only.

How KLOW Works

KLOW has no mechanism of its own in the published literature; it is a physical co-formulation, and any account of how it acts extrapolates from four separately studied molecules. GHK-Cu acts chiefly as a copper(II)-binding vehicle, associated by Pickart and Margolina with shifts in collagen, antioxidant and angiogenic gene expression — a signature-level observation, not demonstrated control. BPC-157's reported mechanism centres on nitric-oxide signalling, its rodent effects abolished by the NOS inhibitor L-NAME. Thymosin beta-4 and its LKKTETQ motif sequester monomeric G-actin; the motif is the minimal actin-binding element and the site linked to angiogenic activity. KPV is mechanistically unrelated, entering cells through the transporter PepT1 and inhibiting NF-kappaB intracellularly, an effect lost in PepT1-knockout animals (Dalmasso et al., 2008). Whether these pathways interact additively, synergistically or antagonistically has never been tested.

Research Findings

There is no published research on KLOW itself. PubMed and ClinicalTrials.gov return no pharmacokinetic, safety, efficacy or stability study of the four-peptide combination or the three-peptide blend it extends, and nothing establishes that the components are chemically compatible co-lyophilised in one vial. Component evidence is very uneven. Only thymosin beta-4 has meaningful human data: completed Phase 1 intravenous safety studies and mixed Phase 3 ophthalmic results, one trial positive for corneal healing while the European SEER-3 trial missed its primary endpoint. BPC-157 has no completed controlled human efficacy trial; a 2025 systematic review found 35 of 36 musculoskeletal studies preclinical, the literature concentrated in one patent-holding group. FDA reports no identified human exposure data for KPV by any route, and controlled human data for injectable GHK-Cu are limited. Regulatory status is widely misreported. All four were previously in Category 2 of FDA's interim bulk-substances policy, but on the listing current 22 April 2026 none remains there: each sits instead under bulk substances nominated but withdrawn — withdrawn by the nominators, which is not approval or endorsement. FDA's Pharmacy Compounding Advisory Committee met on 23 July 2026 to weigh BPC-157-, KPV- and TB-500-related substances for the 503A Bulks List (GHK-Cu was not on that agenda), with no outcome published at the time of writing. WADA prohibits BPC-157 (S0) and thymosin beta-4 derivatives including TB-500 (S2.3) at all times.

Dosage & Administration

No dosing protocol for the KLOW blend exists in any published study. The combination has never been administered in a registered trial, so there is no reference regimen, no rationale for the marketed ratio and no pharmacokinetic profile for the mixture. The figures below come from published research on the individual components, in the species and by the routes actually studied, and are reproduced only as a pointer to the primary literature.

  • Thymosin beta-4 — the only component with human dose-ranging data. A first-in-human randomised, double-blind Phase 1 study gave single intravenous doses of recombinant human thymosin beta-4 to 54 healthy volunteers across seven cohorts at 0.05, 0.25, 0.5, 2.0, 5.0, 12.5 and 25.0 µg/kg. A separate Phase 1a/1b programme gave intravenous single doses of 42, 140, 420 and 1260 mg to 40 healthy volunteers, the Phase 1b arm repeating those doses daily for 14 days. Ophthalmic work used a 0.1% topical solution rather than systemic dosing.
  • BPC-157 — rodent studies characteristically use intraperitoneal or intragastric administration, with 10 µg/kg and 10 ng/kg typical of that literature rather than verified per study. Pharmacokinetic work in rats and beagle dogs reports linear kinetics and an elimination half-life under 30 minutes after intravenous or intramuscular dosing. No controlled human dose-finding study has been published.
  • KPV — published work is confined to cell culture and rodent colitis models (DSS- and TNBS-induced) using oral and luminal delivery, including nanoparticle-encapsulated formulations. Specific milligram-per-kilogram figures vary between studies and are best read directly from the source papers. FDA states it has identified no human exposure data for KPV by any route.
  • GHK-Cu — in vitro studies typically work in the nanomolar to micromolar range, and dermatological research has largely used topical formulations. For endogenous context, Pickart and Margolina report plasma GHK of approximately 200 ng/mL at age 20, declining to approximately 80 ng/mL by age 60. Controlled human data for injectable GHK-Cu are limited.

No standardized human dosing exists for KLOW or for any of its four components. None is approved by FDA or any comparable regulator for human use, and the figures above describe what investigators administered in published experiments, not a protocol for use. Research use only; not for human or veterinary administration.

Safety & Side Effects

There is no adverse-event data for the KLOW blend. No study has administered these four compounds together, so the safety profile of the combination — including any interaction between the copper(II) load of GHK-Cu and the other three peptides — is entirely uncharacterised. What follows is what has been reported for the components individually.

  • Thymosin beta-4 — the component with the most human exposure. Phase 1 intravenous studies in healthy volunteers reported adverse events of mild to moderate intensity, with no dose-limiting toxicities and no serious adverse events across the ranges tested; ophthalmic Phase 3 work reported no significant treatment-attributed effects. This reflects short-duration, controlled, pharmaceutical-grade administration in small populations, not chronic use.
  • BPC-157 — rodent studies have generally not reported overt toxicity, but no human safety dataset exists. FDA has flagged immunogenicity risk for certain routes, complexities of peptide-related impurities and active-ingredient characterisation, and that it identified no, or only limited, safety-related information. Theoretical concern centres on angiogenic activity, since a compound promoting new blood-vessel formation has not been shown to distinguish wanted from unwanted tissue growth; this remains unresolved in any species.
  • KPV — no human adverse-event data exists; FDA states it has not identified any human exposure data for KPV by any route. Rodent colitis studies reported no significant toxicity, but these were short efficacy experiments, not toxicology studies.
  • GHK-Cu — topical dermatological use has a long record of generally mild local effects, but injectable use is a different matter, with limited human data and flagged aggregation and impurity risk. Cumulative copper exposure from repeated administration has not been quantified.

Immunogenicity and peptide-related impurities have been raised by FDA for several of these substances. Because research-grade material is not manufactured to pharmaceutical standards, impurity content, endotoxin load and the actual identity of vial contents are unverified independently of the supplier's own certificate. In sport, BPC-157 (WADA S0) and thymosin beta-4 and its derivatives including TB-500 (WADA S2.3) are prohibited at all times, in and out of competition.

Important: All safety information is derived from published research, primarily animal studies. No controlled human clinical trial data exists unless explicitly noted. This compound is sold for research purposes only.

Quick Facts

Sequence Blend — no single sequence; see the component sequences in the Overview
Molecular Weight Not applicable to a blend — components span 340.38 to approximately 4963 g/mol
Half-Life Not established for the blend; rodent and dog work reports under 30 minutes for BPC-157
Form Lyophilized powder
Available Sizes 80mg
Storage Lyophilized: −20°C long-term, protected from light and moisture; reconstituted with bacteriostatic or sterile water: 2–8°C with short working stability, avoiding repeated freeze-thaw — the copper(II) content makes this blend more oxidation- and light-sensitive than a single-peptide vial, a chemical inference rather than a published finding for this product.

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