Quick answer
What is the GLOW peptide blend? GLOW is a co-lyophilized laboratory blend of three synthetic peptides in a single vial: GHK-Cu (50 mg), BPC-157 (10 mg) and TB-500 (10 mg), 70 mg in total. It is reconstituted with bacteriostatic water to a clear blue solution; 5 mL gives 10 mg/mL GHK-Cu and 2 mg/mL each of BPC-157 and TB-500. Store the dry vial at −20 °C and the reconstituted solution at 2–8 °C for up to about 28 days.
"GLOW" is a vendor nickname rather than a scientific term, which is why a clear definition is hard to find. This overview explains exactly what is in the vial, what each component is at the molecular level, what the published literature does and does not say about the combination, and how to handle the blend at the bench, including the per-component concentration math that a three-peptide vial requires. For laboratory research use only; not for human consumption.
What the GLOW blend is
The GLOW stack is a fixed-ratio mixture, freeze-dried together so that one reconstitution step yields all three peptides in a single solution. The ratio is 5 : 1 : 1 by mass.
| Component | Mass per 70 mg vial | Share of total mass | Type | Approx. molecular weight |
|---|---|---|---|---|
| GHK-Cu | 50 mg | 71.4% | Tripeptide–copper(II) complex | ≈ 340 g/mol (peptide); ≈ 404 g/mol (complex) |
| BPC-157 | 10 mg | 14.3% | 15-residue linear peptide | ≈ 1,419.5 g/mol |
| TB-500 | 10 mg | 14.3% | 43-residue linear peptide (thymosin beta-4 sequence) | ≈ 4,963 g/mol |
A blend is a convenience format. It suits protocols that call for these three compounds together at this ratio, and it removes two reconstitution steps and two sets of calculations. It does not suit designs that need to vary one component independently; those call for separate vials. The general trade-offs are discussed in peptide blends and research stacks.
The three components
GHK-Cu
GHK is the tripeptide glycyl-L-histidyl-L-lysine, first isolated from human plasma and described by Pickart and Thaler in 1973. It binds copper(II) with high affinity through its glycine amine, histidine imidazole and the intervening amide nitrogen, and the resulting complex, GHK-Cu, is intensely blue. In the laboratory it is used in copper-transport studies and in cell-culture experiments examining extracellular-matrix gene expression, particularly in fibroblasts. Further reading: GHK-Cu chemical structure and synthesis and GHK-Cu in skin and collagen research.
BPC-157
BPC-157 is a synthetic pentadecapeptide with the sequence GEPPPGKPADDAGLV. It corresponds to a fragment of a larger protein originally characterized from gastric juice, and its three consecutive prolines give it an unusually rigid, protease-resistant backbone for a peptide of its size. Published work is predominantly preclinical, in rodent and cell models, and has examined angiogenesis-related signaling and nitric-oxide pathways. See BPC-157 mechanism of action.
TB-500
TB-500 is the research-market name for the synthetic form of thymosin beta-4, a 43-amino-acid peptide that is the principal G-actin-sequestering molecule in most mammalian cells. By binding actin monomers it influences cytoskeletal assembly, which is why it appears in cell-migration and actin-dynamics assays. Some suppliers use the name for a short active-site fragment rather than the full sequence, so the identity data on the certificate of analysis should be checked. See TB-500 mechanism of action.
Why these three are combined: the research rationale
The three peptides act through different, non-overlapping molecular entry points, which is the stated reason investigators study them side by side.
| Peptide | Primary molecular handle | Typical model systems | Readouts commonly measured |
|---|---|---|---|
| GHK-Cu | Copper(II) coordination; gene-expression modulation | Cultured fibroblasts and keratinocytes | Collagen and matrix-protein transcripts, metalloproteinase expression |
| BPC-157 | Angiogenic and nitric-oxide signaling pathways | Rodent models; endothelial cell culture | VEGFR2 pathway activation, tube formation |
| TB-500 | G-actin sequestration | Migration (scratch) assays; endothelial and epithelial cells | Cell motility, actin polymerization state |
Is there research on this specific combination?
This is the point on which accuracy matters most. Each component has its own body of literature. BPC-157 and thymosin beta-4 are frequently discussed together (see BPC-157 and TB-500 combination research). However, we are not aware of peer-reviewed studies that have evaluated the three-peptide GLOW mixture, at this ratio, as a defined test article. Any claim that the blend has been shown to produce a combined or synergistic effect goes beyond the published evidence. The blend is best understood as a practical format for laboratories that wish to investigate that open question, not as a validated combination.
GLOW compared with related blends
| Blend | Components | Typical total mass | Solution color |
|---|---|---|---|
| GLOW | GHK-Cu + BPC-157 + TB-500 | 70 mg (50 / 10 / 10) | Blue |
| KLOW | GHK-Cu + KPV + BPC-157 + TB-500 | 80 mg | Blue |
| Wolverine | BPC-157 + TB-500 | Varies by vial | Colorless |
| Individual vials | GHK-Cu, BPC-157, TB-500 | Per product | Blue (GHK-Cu) or colorless |
KLOW differs from GLOW only by the addition of the tripeptide KPV; handling for that vial is covered in KLOW stack reconstitution and storage.
How to reconstitute the GLOW blend
Choosing the diluent
All three peptides dissolve freely in water. For a vial that will be entered more than once, use bacteriostatic water, whose 0.9% benzyl alcohol inhibits microbial growth between punctures. Sterile water is acceptable for same-day use or immediate aliquoting. Because the blend contains copper, avoid making the stock in phosphate buffers (risk of copper phosphate precipitation), in anything containing EDTA or other chelators, in strongly acidic solutions, or with reducing agents such as ascorbate.
Bench procedure
- Let the sealed vial stand at room temperature for 15–30 minutes.
- Check the seal, the cake (pale blue to blue is normal) and the lot number against the COA.
- Swab the stoppers of the peptide vial and the diluent vial with 70% isopropyl alcohol; allow to dry.
- Draw the planned volume of diluent with a sterile syringe.
- Insert the needle at an angle and release the water slowly down the inner glass wall.
- Swirl or roll gently until dissolved. Do not shake or vortex.
- Confirm a clear, uniformly blue solution free of particles.
- Label with date, diluent, volume and the concentration of each component; refrigerate.
Concentration math for the 70 mg vial
Each component is calculated on its own mass: concentration (mg/mL) = component mass (mg) ÷ diluent volume (mL). Dividing 70 mg by the volume gives total peptide concentration, which is useful for solubility but is not the concentration of any single analyte. The right-hand columns give the mass of each component in 10 units (0.1 mL) on a U-100 laboratory syringe scale, where 100 units = 1 mL.
| Diluent added | GHK-Cu (mg/mL) | BPC-157 (mg/mL) | TB-500 (mg/mL) | Total peptide (mg/mL) | GHK-Cu per 10 units | BPC-157 per 10 units | TB-500 per 10 units |
|---|---|---|---|---|---|---|---|
| 2 mL | 25 | 5 | 5 | 35 | 2,500 mcg | 500 mcg | 500 mcg |
| 3 mL | 16.67 | 3.33 | 3.33 | 23.33 | 1,667 mcg | 333 mcg | 333 mcg |
| 4 mL | 12.5 | 2.5 | 2.5 | 17.5 | 1,250 mcg | 250 mcg | 250 mcg |
| 5 mL | 10 | 2 | 2 | 14 | 1,000 mcg | 200 mcg | 200 mcg |
| 7 mL | 7.14 | 1.43 | 1.43 | 10 | 714 mcg | 143 mcg | 143 mcg |
Which volume to choose:
- 5 mL produces the roundest numbers: 10 mg/mL GHK-Cu and 2 mg/mL each of BPC-157 and TB-500, or 100 mcg and 20 mcg per unit mark respectively.
- 4 mL gives 2.5 mg/mL of each minor component (25 mcg per unit mark), matching the per-component figures of a 4 mL KLOW fill.
- 7 mL gives exactly 10 mg/mL total peptide, if the vial is large enough.
- 2–3 mL is the practical range for a 3 mL vial; the solution will be a darker blue and more concentrated.
Always check vial capacity first, and use the reconstitution calculator for volumes not shown.
Unit-scale reference at a 5 mL fill
| Units (U-100) | Volume | GHK-Cu | BPC-157 | TB-500 | Total peptide |
|---|---|---|---|---|---|
| 1 | 0.01 mL | 100 mcg | 20 mcg | 20 mcg | 140 mcg |
| 5 | 0.05 mL | 500 mcg | 100 mcg | 100 mcg | 700 mcg |
| 10 | 0.10 mL | 1 mg | 200 mcg | 200 mcg | 1.4 mg |
| 25 | 0.25 mL | 2.5 mg | 500 mcg | 500 mcg | 3.5 mg |
| 50 | 0.50 mL | 5 mg | 1 mg | 1 mg | 7 mg |
| 100 | 1.00 mL | 10 mg | 2 mg | 2 mg | 14 mg |
Molar perspective
| Component | Concentration at 5 mL fill | Approximate molarity |
|---|---|---|
| GHK-Cu | 10 mg/mL | ≈ 24.8 mM |
| BPC-157 | 2 mg/mL | ≈ 1.41 mM |
| TB-500 | 2 mg/mL | ≈ 403 µM |
On a molar basis the blend is even more GHK-Cu-dominant than the 5 : 1 : 1 mass ratio suggests: roughly 60 molecules of GHK-Cu for every molecule of TB-500. These figures assume 100% peptide content; adjust with the net peptide content and purity on the COA for exact work.
Storage and handling
| State | Temperature | Working window | Key precautions |
|---|---|---|---|
| Lyophilized, long-term | −20 °C | 12–24+ months | Sealed, boxed, dry |
| Lyophilized, short-term | 2–8 °C | Up to a few months | Equilibrate before opening |
| Lyophilized, transit | Ambient | Days | Cold-store on arrival |
| Reconstituted in bacteriostatic water | 2–8 °C | Up to about 28 days | Dark, upright, minimal bench time |
| Reconstituted in sterile water | 2–8 °C | Same day | Unpreserved; aliquot and freeze if needed |
| Frozen single-use aliquots | −20 °C or colder | 1–3 months | Low-bind tubes; thaw once |
The 28-day limit is the convention for preserved multi-use containers, grounded in antimicrobial effectiveness testing (USP <51>) and the beyond-use provisions of USP <797>. It is not a measured shelf life for this blend. Of the three components, TB-500 is the longest and contains methionine, so it is the most vulnerable to oxidation and aggregation; handling the whole vial by the standard that protects TB-500 (cold, dark, no agitation, no repeated freeze–thaw) is the safe approach.
Using color as a check
The copper complex makes the solution a built-in indicator. Clear blue is normal. Haze, sediment, or drift toward green, brown or colorless points to copper displacement, reduction, precipitation or contamination, and the vial should be withdrawn from use. Note that color confirms nothing about BPC-157 or TB-500, which are colorless; their integrity can only be established analytically.
Quality documentation
A blend COA should identify and quantify each peptide, not report a single combined purity figure. Look for HPLC data that resolves the components and mass-spectrometry confirmation for each. Our guides to GHK-Cu purity testing, BPC-157 handling and TB-500 handling give component-level detail.
Blend or separate vials?
| Consideration | GLOW blend | Three individual vials |
|---|---|---|
| Reconstitution steps | One | Three |
| Ratio between peptides | Fixed at 5 : 1 : 1 | Fully adjustable |
| Single-component controls | Not possible from the blend alone | Straightforward |
| Calculation burden | One volume, three concentrations | Three independent calculations |
| Contamination opportunities | Fewer (one vial) | More (three vials) |
| Best suited to | Fixed-ratio combination protocols | Factorial designs and concentration–response work on each peptide |
A rigorous combination study generally needs both: the blend as the test article and individual vials for the single-agent arms.
Related resources
- GLOW stack: GHK-Cu + BPC-157 + TB-500
- Research peptide stacks in 2026
- How to mix peptides with bacteriostatic water
- Storing research peptides
References
- Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol. 1973;243(124):85-87.
- Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018;19(7):1987.
- Sikiric P, Seiwerth S, Rucman R, et al. Brain-gut axis and pentadecapeptide BPC 157: theoretical and practical implications. Curr Neuropharmacol. 2016;14(8):857-865.
- Safer D, Elzinga M, Nachmias VT. Thymosin beta 4 and Fx, an actin-sequestering peptide, are indistinguishable. J Biol Chem. 1991;266(7):4029-4032.
- Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012;12(1):37-51.
- United States Pharmacopeia. General Chapter <797> Pharmaceutical Compounding—Sterile Preparations. USP–NF.
- United States Pharmacopeia. General Chapter <51> Antimicrobial Effectiveness Testing. USP–NF.
- Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544-575.
Frequently Asked Questions
What is in the GLOW peptide blend?
Three synthetic peptides co-lyophilized in one vial: 50 mg GHK-Cu, 10 mg BPC-157 and 10 mg TB-500, for 70 mg in total. It is sold as a laboratory research reagent.
What does GLOW stand for?
It is a vendor nickname for the GHK-Cu, BPC-157 and TB-500 combination rather than a formal scientific acronym. The peptide identities and masses on the label and COA are what define the product.
How much bacteriostatic water should I add to a 70 mg GLOW vial?
Five milliliters gives convenient round numbers: 10 mg/mL GHK-Cu and 2 mg/mL each of BPC-157 and TB-500. Four milliliters gives 12.5 mg/mL and 2.5 mg/mL respectively. Use 2–3 mL if the vial is small, and recalculate.
Why is the GLOW solution blue?
GHK-Cu contains copper(II), which gives the complex a blue color in the solid and in solution. A clear blue liquid is expected; cloudiness or a color shift is a warning sign.
How long does reconstituted GLOW last?
Up to about 28 days at 2–8 °C in bacteriostatic water, protected from light. That figure is the standard convention for preserved multi-use containers, not a stability measurement specific to the blend.
How should the lyophilized GLOW vial be stored?
Sealed and boxed at −20 °C for long-term storage, or at 2–8 °C for a few months. Let the vial reach room temperature before piercing the stopper to avoid condensation.
Has the three-peptide combination been studied in published research?
The individual peptides each have a published preclinical literature, but we are not aware of peer-reviewed studies that test this specific three-peptide blend at this ratio. Claims of demonstrated combined effects are not supported by published evidence.
What is the difference between GLOW and KLOW?
KLOW contains the same three peptides plus 10 mg of the tripeptide KPV, for 80 mg in total. GLOW is the three-peptide, 70 mg version.
Can I change the ratio of peptides in the blend?
No. The 5 : 1 : 1 mass ratio is fixed at manufacture. Diluting changes all three concentrations together. To vary one peptide independently, use individual vials.
Can GLOW be mixed with PBS or saline?
Prepare the stock in bacteriostatic or sterile water. Phosphate can precipitate copper at stock concentrations. Buffers and media are suitable for final working dilutions made immediately before use.
How many units on a U-100 syringe scale contain 1 mg of GHK-Cu at a 5 mL fill?
At 10 mg/mL GHK-Cu, 1 mg occupies 0.1 mL, which is 10 units. The same 10 units contain 200 mcg each of BPC-157 and TB-500.