KLOW is a commercial name for a vial that holds four peptides at once: GHK-Cu, BPC-157, TB-500 and KPV. GLOW is the same mix without KPV. Both are sold as research products and by some clinics for skin, healing and inflammation, and both appear in search with the question "what are the side effects?". The honest answer starts with a fact about the blends themselves: they have never been studied. This page sets out what each component's record holds, what the adverse-event database shows for blended vials, and what a blend makes impossible to know. It recommends nothing. The composition and dose arithmetic of the vials are on our KLOW dosage page.
The blend's own record
| Source | Query, 2 October 2026 | Result |
|---|---|---|
| ClinicalTrials.gov | "KLOW"; "GLOW peptide" | 1 and 13 text matches, none about either blend (an inhaler education programme; trials with GLOW acronyms) |
| ClinicalTrials.gov | any named peptide combination (site census, 16 September 2026) | 0 |
| openFDA adverse events | "KLOW" | no matches |
| openFDA adverse events | "GHK-Cu" | 2 reports, both listing it as concomitant, one of them a GLOW-labelled vial |
| FDA-approved products | any of the four peptides | none |
Component by component
| Component | Share of an 80 mg KLOW vial | Human data by injection under the skin | FDA's 2026 position |
|---|---|---|---|
| GHK-Cu | 50 mg (62.5%) | None located; human studies are topical cosmetic | "Limited data in humans"; injectables may pose immunogenicity risk from aggregation and impurities |
| BPC-157 | 10 mg (12.5%) | None; human studies were enemas, knee and bladder-wall injections and two IV infusions | "Insufficient clinical safety information to characterize the safety profile" |
| TB-500 | 10 mg (12.5%) | None by any route | "Potential safety risks … in humans are unknown" |
| KPV | 10 mg (12.5%) | None by any route | No human exposure data "via any route of administration" |
GHK-Cu is the best-studied component, and its studies are on the skin: a cosmetic-ingredient safety review in 2014 and small topical trials (summarised on our GHK-Cu dosage page). FDA's compounding-risk page (updated 22 April 2026) lists injectable GHK-Cu among substances that may raise immune reactions because the peptide can aggregate and carry impurities.
BPC-157: FDA's May 2026 evaluation found five small human studies, none by the subcutaneous route vendors describe, and safety monitoring it called mostly unclear. Our BPC-157 side-effects page reads that review in full.
TB-500: FDA's evaluation found no clinical study, case report or human exposure data, and no toxicology study of the heptapeptide. Side-effect tables quoted for it usually come from thymosin beta-4, the parent protein, tested as eye drops and gels. See our TB-500 side-effects page.
KPV: FDA's July 2026 briefing document found no information on any product containing KPV given to humans, and no reports from outsourcing pharmacies of compounding it between January 2017 and June 2025. In cadaver skin, it barely permeated. Our KPV dosage page describes a literature dominated by delivery chemistry.
What the adverse-event database shows
Two FAERS reports name GHK-Cu, and both list it as a concomitant product rather than the suspect:
- Received 2026-05-27: a vial described as "GLOW GHK-CU/BPU 157/ TB 500 100 MG/10 MG/10 MG" is listed beside chorionic gonadotropin and Ozempic, which are coded as the suspect drugs; the reactions coded are malignant lymphoid neoplasm, adverse drug reaction, and product dispensed by an unauthorised provider. The vial's stated GHK-Cu content, 100 mg, is double the 50 mg in the KLOW vials this site has read.
- Received 2025-06-26: GHK-Cu and BPC-157 are listed as concomitant to compounded sermorelin, the suspect, in a report of hypersensitivity, low heart rate, low blood pressure, sweating, flushing and blurred vision.
A third report, on a two-peptide BPC-157/TB-500 vial, is the one FDA's reviewers discussed: diffuse darkening of the skin and gums that returned when the product was restarted. FDA judged it likely product-related and could not say which peptide — or what else in the vial — was responsible.
A report listing a product shows that someone used it around the time of an event. It is not a finding that the product caused it, and low counts for unapproved products mostly reflect who reports, not what happens.
The copper nobody has measured
GHK-Cu is a peptide bound to copper. In the 1:1 complex catalogued by PubChem (molecular weight 402.9), copper is about 15.8% of the mass. Some products use a 2:1 complex (molecular weight about 742), which is about 8.6% copper.
| Amount | GHK-Cu | Copper (1:1 complex) |
|---|---|---|
| 80 mg KLOW vial (50 mg GHK-Cu) | 50 mg | ≈7.9 mg |
| Draw holding 500 mcg BPC-157 from that vial | 2.5 mg | ≈0.39 mg |
| Draw holding 500 mcg BPC-157 from a 100 mg-GHK-Cu GLOW vial (100/10/10) | 5 mg | ≈0.79 mg |
These are arithmetic from the labelled contents, not measurements. Food copper is absorbed through the gut and regulated by the liver; an injection under the skin bypasses the first of those steps. No published study has measured blood or tissue copper after injected GHK-Cu, at any dose, in anyone.
What a blend makes impossible
A premixed vial fixes the ratio. Any draw sized for one component delivers the others in proportion, so in the 80 mg KLOW vial a draw holding 500 mcg of BPC-157 also holds 2,500 mcg of GHK-Cu. Three consequences follow for side effects:
- Attribution is lost. If a reaction follows, the blend cannot say which component caused it. FDA met this with a two-peptide vial; a four-peptide vial doubles the problem.
- Dose of the least-studied component is set by the most-dosed one. Whatever logic sizes the draw, KPV and TB-500 — the two with no human data — come along at a fixed share.
- Vials differ. Clinic and vendor versions of the "same" blend have listed GHK-Cu from 20% to 62.5% of the peptide mass, and the FAERS GLOW vial lists 100 mg. A side effect report from one blend says nothing about another.
Reading this record
"No known side effects" is not what the record shows. It shows a blend never tested, three components with no human injection data, a fourth with little, two adverse-event reports in which the blend is a bystander, and an unmeasured copper dose. Anyone who has used KLOW or GLOW and has symptoms should tell a doctor what the label said was in the vial and where it was bought.
What is claimed for the blends' benefits, and what the cosmetic record supports, is covered on PeptideGlowJournal's KLOW peptide page. Why stacked peptides are hard to study generally is on our peptide stacks page, and why low report counts for research compounds mean little is on our peptide side-effects overview.
Sources and dates
- ClinicalTrials.gov v2 API, terms "KLOW" and "GLOW peptide", read 2026-10-02 (no relevant record).
- openFDA drug adverse-event endpoint, medicinal product "KLOW", "GHK-CU", "GHK CU", "KPV", "GLOW" (27 hits, 1 peptide-related), read 2026-10-02; dataset updated 2026-07-30.
- FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (content current as of 2026-04-22): GHK-Cu, BPC-157 and KPV entries, read 2026-10-02.
- FDA briefing document, Pharmacy Compounding Advisory Committee, 23–24 July 2026: KPV (fda.gov/media/193346), human safety and compounding-history sections, read 2026-10-02; BPC-157 (fda.gov/media/193343) and TB-500 (fda.gov/media/193349) as read for this site's side-effect pages on 2026-09-25 and 2026-09-26.
- PubChem CID 71587328 (copper tripeptide-1, C14H23CuN6O4+, 402.92 g/mol) and CID 9831891 (2:1 complex, 742.3 g/mol), read 2026-10-02.
- Blend compositions: this site's KLOW dosage page (Prime Labs, Medica Depot and BHR Center product pages, opened 2026-09-17).
Corrections go to the contact page.