Source: https://peakpeptides.com/peptides/klow/ Peptide library · Blend # KLOW A co-formulated blend of KPV, GHK-Cu, BPC-157 and TB-500, not a new molecule. No controlled study has tested KLOW itself; the research belongs to each component separately and is mostly preclinical. Last reviewed September 22, 2026 At a glance - **Also called:** KLOW peptide; KLOW blend; four-peptide blend - **What it is:** A four-component peptide mixture - **Evidence:** No blend trials; component research is mostly preclinical - **FDA status:** Not FDA-approved for any use - **In sport:** Contains WADA-prohibited BPC-157 (S0) and TB-500 - **At Promise Peptides:** Listed; currently waitlist-only The short version KLOW is a mixture of four separate peptides: KPV, GHK-Cu, BPC-157 and TB-500. They remain different molecules when placed in one formulation. There is no controlled research on the blend as a blend, no established human pharmacology for the combination and no evidence that co-formulation creates synergy. Component evidence comes mainly from cells and animals. KLOW is not FDA-approved. Several components appear in FDA’s withdrawn-nomination table, and their safety notes remain. Promise’s listing does not change those FDA facts. ## What it is KLOW is a co-formulation, not a single peptide. KPV is the three-amino-acid C-terminal fragment of alpha-melanocyte-stimulating hormone. GHK-Cu is a three-amino-acid copper complex. BPC-157 is a synthetic chain of 15 amino acids. TB-500 is the acetylated seven-amino-acid sequence Ac-LKKTETQ, a fragment associated with the 43-amino-acid protein thymosin beta-4. Because KLOW is a mixture, it has no single sequence, molecular formula, molecular weight or CAS number. The name KLOW does not by itself establish a standardized formulation. A fixed label ratio is not evidence that the components interact predictably in the vial or in the body. ## Where the research stands No controlled study has tested KLOW, compared it with its components or characterized the mixture’s stability and pharmacokinetics. The cards below are component studies only. They describe KPV, GHK-Cu, BPC-157 or full-length thymosin beta-4, not the four-part blend. How far the evidence has climbed 1. Cell studies · None · No study of the complete blend 2. Animal studies · None · Components studied separately 3. Small human pilots · None · No human KLOW pilot identified 4. Controlled human trials · None · No controlled trial of KLOW 5. FDA approval · No · No approved KLOW product Here is what selected component studies looked at. Each card names the component and species because it is not evidence about KLOW itself. - **KPV alone: intestinal models** (Cells · Mice · 2008): KPV was studied in human intestinal and immune cells and in two mouse colitis models. Researchers measured PepT1 transport and inflammatory signaling; the KLOW blend was not used.[1] - **GHK-Cu alone: fibroblasts** (Human cells · 1988): This study measured collagen synthesis and cell number in cultured human fibroblasts. It did not test KLOW, injection into people or a clinical outcome.[2] - **BPC-157 alone: tendon model** (Rats · Cells · 2003): In rats with a cut Achilles tendon and rat tendon cells in culture, researchers measured mechanical, microscopic and cell-outgrowth changes after BPC-157. KLOW was not tested.[3] - **Full protein: skin wounds** (Rats · 1999): A rat wound study tested full-length thymosin beta-4 and measured wound closure, collagen and blood-vessel formation. It did not test the short TB-500 fragment or KLOW.[4] - **BPC-157 alone: two adults** (Humans · 2025): A pilot report administered BPC-157 to two healthy adults and recorded short-term laboratory observations. With no comparison group and only two people, it cannot establish safety or effectiveness, and it says nothing about KLOW.[5] - **Unapproved component review** (Review · 2026): A sports-medicine review found that rigorous human safety data for unapproved peptides including BPC-157 and TB-500 are scarce. It did not identify a KLOW trial.[6] ## What the research can’t tell you - **The blend is untested**: No direct safety, effectiveness or pharmacokinetic data exist for all four components together. Synergy is a hypothesis, not a finding. - **TB-500 evidence is often misassigned**: Most tissue-repair papers used full-length thymosin beta-4, not the short TB-500 fragment. The parent protein’s results cannot be transferred automatically.[4] - **Four different molecules, four different gaps**: The cited KPV research is preclinical; the cited GHK-Cu study used cultured fibroblasts; BPC-157 evidence is mostly from rodents; and the cited TB-500 literature does not establish human fragment safety or effectiveness. - **Mixture compatibility is unknown**: GHK-Cu carries a copper ion, while the other peptides have their own stability and clearance patterns. How co-formulation affects oxidation, degradation or exposure has not been established. - **Repair pathways can raise theoretical concerns**: Several component studies involve cell movement or new blood-vessel formation. Any tumor concern is reasoning from mechanism and animal or cell work, not a finding in people using KLOW. - **Sport prohibition**: WADA prohibits BPC-157 under S0 and names TB-500 and thymosin beta-4 derivatives among prohibited growth-factor modulators, so the blend creates an anti-doping issue.[7] ## FDA status Not FDA-approved for any use There is no FDA-approved KLOW combination product. A compounded combination also does not receive FDA approval, and FDA does not verify a compounded drug’s safety, effectiveness or quality before marketing.[8] FDA’s page, content current as of April 22, 2026, includes BPC-157, injectable GHK-Cu, KPV and the thymosin beta-4 fragment identified as TB-500 in its withdrawn-nomination table. FDA still publishes safety notes beside the entries. Withdrawal is not FDA approval, and the other compounding requirements still apply.[9] None appears on FDA’s finalized list of additional bulk substances for patient-specific compounding.[10] FDA staff later proposed against listing BPC-157, KPV and TB-500, and no official advisory-committee vote record was posted as of September 17, 2026.[11] Those component-level facts are separate from a licensed provider’s clinical decision. Promise Peptides is currently taking waitlist sign-ups. Joining is not a medical request and no prescription comes from it. ## A prescription route Promise is currently accepting waitlist signups. Joining is not a treatment request and does not result in a prescription. If treatment visits open, any treatment request would require clinical review; prescribing and pharmacy fulfillment would remain separate decisions. 1. **Start on Promise’s KLOW page**: It shows what the treatment involves and its current availability. 2. **Answer the KLOW questionnaire**: A licensed provider reviews health history, medicines and goals, and can decline. Not everyone qualifies. 3. **Pharmacy review is a separate step**: A prescription does not guarantee preparation or dispensing. A pharmacy must separately determine whether it can fulfill the prescription under the applicable requirements. A prescription does not make KLOW FDA-approved, prove the blend has synergy or erase the component-level evidence gaps; it reflects an individualized clinical decision. KLOW at Promise Read the treatment information and view the current waitlist. [Join the Promise waitlist](https://mypromise.com/products/klow?utm_source=peak&utm_medium=affiliate&utm_campaign=library&utm_content=klow) Peak may earn money when readers become Promise patients. Joining does not guarantee future treatment availability. Availability would depend on the treatment, state, clinical review and separate pharmacy review. ## Questions ### What is KLOW peptide? It is a co-formulation of KPV, GHK-Cu, BPC-157 and TB-500. The four ingredients do not become one new molecule when mixed. ### Has the four-peptide KLOW blend been studied in a clinical trial? No controlled KLOW study is identified in the cited research. The cited studies concern individual components or the full parent protein, not the blend. ### How does KLOW compare with GLOW? Both contain GHK-Cu, BPC-157 and TB-500. KLOW adds KPV, but no controlled study shows what that addition changes in people. ## Sources 1. Dalmasso G, et al. PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. *Gastroenterology*. 2008;134:166-178. [PubMed 18061177](https://pubmed.ncbi.nlm.nih.gov/18061177/) 2. Maquart FX, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. *FEBS Lett*. 1988;238:343-346. [PubMed 3169264](https://pubmed.ncbi.nlm.nih.gov/3169264/) 3. Staresinic M, et al. Gastric pentadecapeptide BPC 157 accelerates healing of transected rat Achilles tendon and in vitro stimulates tendocytes growth. *J Orthop Res*. 2003;21:976-983. [PubMed 14554208](https://pubmed.ncbi.nlm.nih.gov/14554208/) 4. Malinda KM, et al. Thymosin beta4 accelerates wound healing. *J Invest Dermatol*. 1999. [PubMed 10469335](https://pubmed.ncbi.nlm.nih.gov/10469335/) 5. Lee E, Burgess K. Safety of intravenous infusion of BPC157 in humans: a pilot study. *Altern Ther Health Med*. 2025. [PubMed 40131143](https://pubmed.ncbi.nlm.nih.gov/40131143/) 6. Mendias CL, Awan TM. Safety and efficacy of approved and unapproved peptide therapies for musculoskeletal injuries and athletic performance. *Sports Med*. 2026. [PubMed 41966639](https://pubmed.ncbi.nlm.nih.gov/41966639/) 7. World Anti-Doping Agency. [The 2026 Prohibited List](https://www.wada-ama.org/en/prohibited-list) (BPC-157 under S0; TB-500 under S2.3). 8. U.S. Food and Drug Administration. [Compounding and the FDA: Questions and Answers](https://www.fda.gov/drugs/human-drug-compounding/compounding-and-fda-questions-and-answers). 9. U.S. Food and Drug Administration. [Certain bulk drug substances for use in compounding that may present significant safety risks](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks). Content current as of April 22, 2026. 10. U.S. Food and Drug Administration. [Bulk drug substances used in compounding under section 503A of the FD&C Act](https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act). 11. U.S. Food and Drug Administration. [July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee](https://www.fda.gov/advisory-committees/advisory-committee-calendar/july-23-24-2026-meeting-pharmacy-compounding-advisory-committee-07232026). ## Also in the library - [GLOW](https://peakpeptides.com/peptides/glow/) (Blend) - [BPC-157](https://peakpeptides.com/peptides/bpc-157/) (Synthetic peptide) - [TB-500](https://peakpeptides.com/peptides/tb-500/) (Synthetic peptide) - [GHK-Cu](https://peakpeptides.com/peptides/ghk-cu/) (Copper tripeptide) --- Peak maps the terrain; it does not examine anyone, so nothing here is medical advice, and the decision about any treatment belongs to a licensed provider who has reviewed your health. Peak may earn money when readers become Promise patients. Peak is not affiliated with any company called Peak Peptides or Peak Performance Peptides.