With BPC-157
Complementary evidenceLv2
An exploratory rat Achilles-tendon study found improved histology versus control for the combination, but no additional benefit over either peptide alone.
Interaction evidence sourceFDA TB-500 assessment All research profiles
Blends
KLOW
Prepared by the ezGLP team. Sources last checked . Profile reviewed .
Also known as GHK-Cu + KPV + BPC-157 + TB-500
Routes represented in the knowledgebase: Subcutaneous (SubQ).
Educational overview
KLOW is listed in the ezGLP knowledgebase under Blends. Evidence and regulatory status can vary by formulation, route, and jurisdiction.
KLOW is a vendor name for a fixed-ratio compounded blend that adds KPV to the GLOW combination, and like other trade-named blends its composition varies by seller. The catalogue entry here records four components, with GHK-Cu accounting for most of the total peptide mass and BPC-157, TB-500, and KPV making up the remainder. GHK-Cu is the copper complex of glycyl-L-histidyl-L-lysine; BPC-157 is a synthetic 15-amino-acid peptide derived from a sequence in gastric juice; TB-500 is a fragment of thymosin beta-4; and KPV is the tripeptide lysine-proline-valine from the C-terminal end of alpha-melanocyte-stimulating hormone.
Fixed-ratio compounded blends carry no combined trial evidence, and no published study has examined these four peptides administered together. Evidence for the parts does not transfer to the mixture, and each part is preclinical or cosmetic. Human GHK-Cu data come from small topical studies rather than from injected use; a 2025 systematic review found no high-quality human evidence for BPC-157; no human clinical trial of TB-500 has been published; and KPV rests on cell and mouse work, including a 2008 Gastroenterology study of PepT1-mediated uptake in colitis models and later nanoparticle delivery studies. The FDA reported in 2023 that it had identified no human exposure data for KPV.
Regulators treat this kind of product as an unapproved compounded preparation rather than a medicine. None of the four components is approved for injection anywhere, and in 2023 the FDA placed injectable GHK-Cu, BPC-157, thymosin beta-4 with its TB-500 fragment, and KPV on its list of bulk drug substances that may present significant safety risks when compounded, citing immunogenicity, aggregation, peptide-related impurities, and in the case of KPV a complete absence of human safety information. In sport, BPC-157 is named under S0 of the WADA Prohibited List and thymosin beta-4 and its derivatives under S2, both prohibited at all times.
KLOW is supplied as a lyophilized powder in one vial, generally blue-tinted from the copper complex, and reconstituted before subcutaneous injection; loss of that colour can indicate copper loss or degradation. Four peptides in one solution have no published stability data, no approved label sets a storage temperature or beyond-use time, and the ratio cannot be reconstructed once the vial is reconstituted. An inventory record therefore usually names each component and its stated amount per vial, together with lot number, reconstitution date, resulting concentration, injection site, and any local reaction, since identity and purity of research-grade material are not independently verified.
- Category
- Blends
- Routes represented
- Subcutaneous (SubQ)
- Storage context
- Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.
Published literature
Safety evidence
Serious or important: potential immunogenicity, aggregation, impurity, or product-quality risks.
A dependable route-specific human interaction and side-effect profile is not established; this is not evidence of no risk.
Safety evidence sourceInteraction evidence
These are general, pairwise evidence notes. Green identifies the potential-synergy category, while Lv3/Lv2/Lv1 communicates evidence strength; it does not guarantee benefit or cancel a safety warning.
With BPC-157
Complementary evidenceLv1
The pair is proposed as complementary from separate preclinical findings involving tendon repair, angiogenic signaling, collagen, and extracellular-matrix accumulation.
Interaction evidence sourceGHK-Cu wound studyFDA peptide safety overviewWith GHK-Cu
Complementary evidenceLv1
The pair is proposed as complementary from separate evidence involving thymosin-beta-4-related cell migration and GHK-Cu-associated matrix accumulation.
Interaction evidence sourceGHK-Cu wound studyFDA TB-500 assessmentWith KPV
Complementary evidenceLv1
The pair is proposed as complementary through separate preclinical rationales involving tissue migration, remodeling, and inflammatory signaling.
Interaction evidence sourceKPV preclinical studyFDA KPV assessmentWith KPV
Complementary evidenceLv1
The pair is proposed as complementary from separate preclinical findings involving extracellular-matrix deposition and reduced inflammatory signaling.
Interaction evidence sourceKPV preclinical studyFDA KPV assessmentCommon questions
What is in the KLOW peptide blend?
The catalogue entry records four components: GHK-Cu, which makes up most of the total peptide mass, plus BPC-157, TB-500, and KPV. The name is a vendor convention rather than a specification, and both the component list and the ratio differ between sellers. Nothing requires two vials sold as KLOW to match, and the batch certificate of analysis is the only description of a given vial.
What is the difference between KLOW and GLOW?
KLOW is generally the GLOW combination with KPV added, which is where the leading K in the name comes from. KPV is a three-amino-acid fragment of alpha-melanocyte-stimulating hormone marketed for an anti-inflammatory rationale drawn from cell and mouse studies. Neither blend has been tested in any published study, and both vary in composition and ratio between sellers.
Is KLOW FDA approved?
No. No regulator has reviewed the combination, and none of its components is approved for injection in any country. In 2023 the FDA placed injectable GHK-Cu, BPC-157, thymosin beta-4 with its TB-500 fragment, and KPV among bulk drug substances that may present significant safety risks when compounded, which removes all four from routine pharmacy compounding under section 503A of the Food, Drug, and Cosmetic Act.
Is there research on combining four healing peptides?
No published clinical or animal study has tested these four peptides as one product. Each was assessed separately by the FDA in 2023 and each is studied separately in the literature, largely in cell culture, rodent models, or, for GHK-Cu, topical cosmetic settings. Whether components in one solution interact chemically or biologically has not been examined for this or any comparable blend.
Is KLOW banned in sport?
Two of its components are named on the WADA Prohibited List: BPC-157 under S0, non-approved substances, and thymosin beta-4 and its derivatives, with TB-500 given as the example, under S2 peptide hormones and growth factors. Both are prohibited at all times, in and out of competition. GHK-Cu and KPV are not named, although the S0 category extends to substances with no human therapeutic approval.
Further reading
- Pickart et al., International Journal of Molecular Sciences 2018 (GHK-Cu gene data review)
- Vasireddi et al., HSS Journal 2025 (systematic review, orthopaedic sports medicine)
- Biological activities of thymosin beta-4 defined by active peptide sequences, FASEB Journal 2010
- Dalmasso et al., Gastroenterology 2008 (PepT1-mediated KPV uptake, mouse colitis)
- Xiao et al., 2017 (oral KPV nanoparticles in mouse colitis, PMC)
- FDA, KPV compounding safety assessment
- FDA, bulk drug substances that may present significant safety risks (2023)
- WADA Prohibited List (S0 non-approved substances; S2 peptide hormones and growth factors)
Summarised from published literature for reference only, with citations to the source. Evidence is graded as reported and is not a recommendation to combine, dose, or use any compound.
For personal tracking and education only. Not medical advice, diagnosis, or treatment, and not a medical device. Peptides may be prescription-only or unapproved where you live. Consult a licensed healthcare professional.