- GLOW is a three-peptide blend: 10 mg BPC-157 + 10 mg TB-500 + 50 mg GHK-Cu (70 mg per vial). KLOW is the identical trio plus 10 mg KPV (80 mg per vial).
- The only difference is KPV (Lys-Pro-Val), a tripeptide from the tail of α-MSH that blocked NF-κB inflammatory signalling at nanomolar levels in human cells and reduced colitis in mice (Dalmasso 2008).
- GLOW fits research on tissue repair and skin matrix: vessel growth, cell migration and collagen. KLOW fits the same questions when inflammation is part of the model, for example inflamed gut or chronically inflamed wounds.
- Neither blend has been tested as a combination in a published study; both are built from component data in cells, animals and, for thymosin beta-4, phase 2 ulcer trials.
GLOW vs KLOW in one sentence
GLOW and KLOW share the same repair core of BPC-157, TB-500 and GHK-Cu in the same amounts, and KLOW simply adds 10 mg of the anti-inflammatory tripeptide KPV. So the real comparison is not between two different formulas, but between a repair-only design and a repair-plus-inflammation-control design. Which one suits a study depends on whether inflammation is a variable the researcher wants to address.
Composition side by side
| GLOW | KLOW | |
|---|---|---|
| BPC-157 | 10 mg | 10 mg |
| TB-500 | 10 mg | 10 mg |
| GHK-Cu | 50 mg | 50 mg |
| KPV | - | 10 mg |
| Total per vial | 70 mg | 80 mg |
| GHK-Cu share by mass | about 71 % | about 63 % |
| Main research theme | Repair, vessels, collagen | Repair + inflammation control |
| Cryopept price | €55 | €70 |
The shared core: what each component is researched for
Both blends are designed around one idea: tissue repair needs several steps to happen together. New blood vessels must reach the damaged area, cells must migrate in, and a new extracellular matrix must be laid down. Each of the three core peptides is associated in research with a different step.
BPC-157: blood vessels and tendon cells
BPC-157 is a 15-amino-acid fragment of a protective protein first described in gastric juice. Most of its literature comes from rat injury models of tendon, ligament, muscle and gut. In a 2011 cell study, BPC-157 accelerated the outgrowth of rat Achilles tendon explants, improved fibroblast survival under oxidative stress and increased fibroblast migration in a dose-dependent way through the FAK - paxillin pathway (Chang et al., J Appl Physiol). Other rodent work links it to VEGFR2 signalling and new vessel growth. Published human trial data for BPC-157 remain very limited.
TB-500: cell migration via actin
TB-500 is a synthetic peptide built on the actin-binding region of thymosin beta-4 (Tβ4), a small protein released by platelets at injury sites. Tβ4 binds G-actin, the building block cells use to move. A 2012 review by Treadwell et al. reports that Tβ4 sped up healing of full-thickness wounds in normal, diabetic, steroid-treated and aged rodents, and in two phase 2 trials in stasis and pressure ulcers it accelerated healing by almost a month in patients who healed. Note that these human data are for full-length Tβ4, not for the shorter TB-500 fragment.
GHK-Cu: collagen and matrix, plus a calming signal
GHK-Cu is the copper complex of glycine-histidine-lysine, a tripeptide found naturally in human plasma. It is the largest component by mass in both blends (50 mg). A 2018 review by Pickart and Margolina summarises cell and animal data showing that GHK increases collagen, elastin and glycosaminoglycan synthesis, supports dermal fibroblasts and stimulates blood vessel and nerve outgrowth, with repair reported in skin, lung connective tissue, bone, liver and stomach lining. The same review notes suppression of NF-κB, which means GLOW already carries a modest anti-inflammatory signal before KPV is added.
- BPC-157 - vessel growth and tendon fibroblast migration (rat and cell studies).
- TB-500 - actin-driven cell migration (Tβ4 animal data plus phase 2 ulcer trials).
- GHK-Cu - collagen, elastin and matrix synthesis, NF-κB suppression (cell and animal data).
What KPV adds in KLOW
KPV is the tripeptide lysine-proline-valine, residues 11-13 of α-melanocyte-stimulating hormone (α-MSH). α-MSH is a melanocortin hormone with well-documented anti-inflammatory effects, and a 2008 Endocrine Reviews paper by Brzoska et al. describes how its C-terminal tripeptide keeps much of that anti-inflammatory activity in a far smaller molecule, without the pigmentation effects of the full hormone.
The key KPV mechanism study is Dalmasso et al. (Gastroenterology, 2008). In human intestinal epithelial cells and human T cells, nanomolar KPV inhibited activation of NF-κB and MAP-kinase pathways and lowered pro-inflammatory cytokine secretion. KPV entered the cells through PepT1, a di- and tripeptide transporter that is normally found in the small intestine but is switched on in the colon during inflammatory bowel disease. Given in drinking water, KPV reduced DSS- and TNBS-induced colitis in mice.
A second 2008 study (Kannengiesser et al., Inflammatory Bowel Diseases) tested KPV in two mouse colitis models. KPV-treated mice recovered earlier, regained body weight faster and showed fewer inflammatory infiltrates and lower myeloperoxidase activity in the colon. In mice with a non-functional melanocortin-1 receptor, KPV rescued every treated animal from death during DSS colitis, which suggests its effect is at least partly independent of MC1R.
Why put this into a repair blend? The inflammatory phase of healing is necessary, but when it drags on it slows the later rebuilding phases. KLOW pairs two anti-inflammatory signals (KPV and GHK-Cu) with two pro-migration and pro-vessel signals (TB-500 and BPC-157), so the design covers both sides of that balance in one vial.
Which research questions fit which blend
| Research focus | Better fit | Why |
|---|---|---|
| Skin matrix, collagen, elastin | GLOW | GHK-Cu dominates; no extra variable |
| Tendon or ligament repair models | GLOW | BPC-157 + TB-500 migration data |
| Wound models without marked inflammation | GLOW | Repair trio alone is the cleaner design |
| Inflamed gut or colitis models | KLOW | KPV data come from colitis models |
| Chronic, inflamed wounds | KLOW | Adds NF-κB inhibition to repair |
| Cytokine or NF-κB readouts | KLOW | KPV acts directly on these pathways |
| Isolating one mechanism | Single peptides | Blends cannot separate component effects |
A practical point for study design: a blend is useful when the question is about combined effects, but it cannot tell you which component caused a result. If a study needs to attribute an effect to KPV, a common approach is to run KLOW against GLOW, since the two differ by exactly one peptide, or to test KPV alone alongside them.
How strong is the evidence?
| Component | Strongest evidence | Key source |
|---|---|---|
| BPC-157 | Rat and cell studies | Chang 2011 |
| TB-500 / Tβ4 | Phase 2 ulcer trials (full Tβ4) | Treadwell 2012 |
| GHK-Cu | Cell and animal studies | Pickart 2018 |
| KPV | Human cells + mouse colitis | Dalmasso 2008 |
| GLOW or KLOW as a blend | No published studies | - |
Adverse events: the component literature is mostly preclinical, so safety data in humans are thin. BPC-157 and TB-500 are on the WADA Prohibited List, which matters for any research involving athletes.
Quality and format
Both Cryopept blends are co-lyophilized in a single 10 ml glass vial, tested to ≥99 % purity by HPLC, with the identity of every component confirmed by LC-MS. Each batch ships with Cryopept's internal test protocol (COA). Because GHK-Cu is sensitive to light and oxidation, both blends should be stored sealed, cold and dark.
For laboratory research use only. Not for human or veterinary use; this article is not medical advice.
