Glow and Klow peptide blends: what they contain and what is known

Glow peptide is a supplier name, not a scientific one. It usually refers to a single vial that combines GHK-Cu, BPC-157 and TB-500. Listings we track describe it in two common formats. The larger one is a 70 mg vial, for example "GLOW 70 MG (50mg GHK, 10mg BPC, 10MG TB500)". The smaller one is sold in multi-vial packs labelled "GHKcu 2mg/BPC 500mcg/TB 500mcg". Both formats keep GHK-Cu as the largest part by mass.

The name is not used consistently. Some listings called Glow contain only GHK-Cu, such as a "GHK-Cu Skin Glow" pre-filled pen, and some say "Glow GHK-Cu 70mg" without listing the other ingredients. A Glow blend label alone does not tell you what is in the vial. Read the listed contents and the certificate of analysis. Our guide on how to read a peptide COA explains what to check.

The name reflects marketing aimed at skin, because GHK-Cu is best known as a cosmetic ingredient. BPC-157 and TB-500 are added because they are sold separately for tissue repair. For background on how these products are sold, see what research peptides are.

Klow peptide is Glow with KPV added. Klow is only thinly represented in the catalogue of suppliers we track, so we rely on how sellers themselves describe it. Two US sellers list the Klow blend as an 80 mg vial containing GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg and KPV 10 mg, and both label it for research use only ^{[16] [17]}. Other listings may differ, and the only way to confirm a vial's contents is independent testing.

KPV is a three-amino-acid peptide (lysine, proline, valine) matching the last three residues of the hormone alpha-MSH. It has been studied for inflammation, mostly in cells and in mice with colitis ^{[9] [10]}.

In the Klow vs Glow comparison, the only difference in the listings we checked is KPV. Both contain the same three peptides in the same amounts in their common large formats. Klow adds 10 mg of KPV, which takes the vial from 70 mg to 80 mg.

Sellers present KPV as an anti-inflammatory addition. The research behind that is limited to laboratory and mouse work. In a 2008 study, nanomolar concentrations of KPV reduced activation of the inflammatory NF-κB and MAP kinase pathways in human intestinal cells and T cells, and KPV given in drinking water reduced chemically induced colitis in mice ^[9]. A second 2008 study found that KPV sped recovery in two mouse colitis models ^[10]. None of this work involved GHK-Cu, BPC-157 or TB-500, and none was in people.

There is no evidence that Klow does anything Glow does not, or the other way round, because neither has been tested. Any difference between them is inferred from separate studies of KPV.

No. We found no published study of Glow or Klow as a blend, in cells, animals or people. Nor did we find any study of GHK-Cu combined with BPC-157, TB-500 or KPV. Effects measured for one peptide alone cannot be assumed to hold when it is mixed with others.

The nearest evidence covers two of the ingredients. In a 2026 rat study, 32 rats with surgically repaired Achilles tendons received BPC-157, TB-500, both, or nothing for four weeks. TB-500 alone gave a significant strength advantage over controls, BPC-157 alone gave scores that were numerically better but not statistically significant, and the combination "did not confer additional benefits" compared with either alone ^[8]. That study did not include GHK-Cu or KPV, and it does not show that Glow or Klow blends work.

Claims about Glow peptide benefits usually concern skin, hair and healing. The evidence for each ingredient is summarised below. None of it tests the blend.

GHK-Cu is the main ingredient by mass. GHK was first reported in human serum in 1973 ^[1], and in 1980 its discoverers showed that it readily forms a complex with copper and increases copper uptake into cultured cells ^[2]. In fibroblast cultures it stimulated collagen synthesis from very low concentrations, with a maximum effect at 10⁻⁹ M ^[3]. Its best clinical result is a 1994 randomised, placebo-controlled trial of a topical gel in diabetic foot ulcers, where median closure of plantar ulcers was 98.5% with GHK-Cu gel against 60.8% with the gel base ^[4]. For wrinkles and skin ageing, a 2025 review found cell data supportive but "a surprising absence of clinical studies" ^[5], and a 2026 systematic review found only two randomised trials among 20 studies of GHK-Cu alone ^[12]. Every human result here is for a topical product. We found no published human trial of injected GHK-Cu.

BPC-157 has been studied mainly in rats for tendon, muscle and gut injury. A 2025 systematic review found 35 preclinical studies and one clinical study, and no clinical safety data ^[6]. TB-500 is a seven-amino-acid fragment of thymosin beta-4 ^[7]. Most research people cite for it used the full-length protein, which improved skin-wound healing in rats and mice ^[13]. None of these studies measured skin appearance in people.

Klow peptide benefits are marketed as Glow plus reduced inflammation. KPV's anti-inflammatory activity is well described in the laboratory. How it works is less settled. A 2003 mouse study concluded that KPV probably acts by inhibiting interleukin-1β rather than through melanocortin receptors ^[11], while the 2008 gut study found it enters cells through the peptide transporter PepT1, which increases in the inflamed colon ^[9].

That evidence is for gut and immune inflammation in mice and cells. We found no study of KPV for skin appearance in people and no human trial of KPV for any purpose. For a closer look at how KPV compares with BPC-157 on gut inflammation, see our KPV guide.

No study has tested any dose of Glow or Klow, so there is no Glow peptide dosage or Klow peptide dosage from research to report. Charts that give daily amounts for these blends are not based on published trials. Doses used for the single ingredients come from different species, routes and molecules. They include topical GHK-Cu gel in human ulcer trials ^[4], BPC-157 at 10 µg/kg/day and TB-500 at 60 µg/kg/day injected into rats ^[8], and KPV in the drinking water of mice ^[9]. These are not interchangeable and should not be converted to human doses.

One arithmetic point applies to every fixed blend. In a vial listed as 50 mg GHK-Cu, 10 mg BPC-157 and 10 mg TB-500, the ratio is fixed at 5:1:1 by mass, and Klow's listed contents fix it at 5:1:1:1. Any volume drawn contains five times as much GHK-Cu as each of the others. The concentration of each peptide after mixing is its listed mass divided by the volume of water added. The peptide calculator does this sum, and our bacteriostatic water guide covers the diluent. Neither indicates what amount, if any, is appropriate.

Side effects of Glow and Klow have not been studied, because the blends have not been studied. What is known comes from the ingredients. Topical GHK-Cu was generally well tolerated in small trials ^[4]. The FDA has said that compounded injectable GHK-Cu may pose a risk of immune reactions because of aggregation and peptide-related impurities, with limited human safety data. It raised similar immune-reaction and impurity concerns for BPC-157 and TB-500, and said it had found no human exposure data at all for KPV ^[14]. There are no human safety data for TB-500 or KPV.

Blends add their own uncertainty. A mixture makes it harder for a buyer or a laboratory to confirm how much of each peptide a vial contains. Products sold online as TB-500 have already been found not to match their descriptions consistently ^[18]. Looking for third-party tested suppliers is one way to reduce that risk, though it cannot make an untested product safe.

Before and after photos of Glow peptide are common on social media, but they are not evidence. Lighting, skincare, time and other treatments all affect how skin looks, and no controlled study of the blend exists to compare them against. The 2026 systematic review of GHK-Cu in aesthetics found that even for topical GHK-Cu alone, the clinical evidence was limited by small numbers and inconsistent methods ^[12].

None of the four peptides is an approved medicine. In the US, the FDA previously placed BPC-157, TB-500, KPV and injectable GHK-Cu in category 2 of its compounding policy, the list of bulk substances that may present significant safety risks. The nominations were later withdrawn, and the FDA now lists them among substances previously in category 2. Withdrawal does not authorise their use ^[14].

Health Canada's April 2026 advisory named BPC-157, GHK-Cu, KPV and TB-500 among seized unauthorised peptides and said research-use labelling does not make such products legal ^[19]. Rules differ by country and are covered on our legal status pages, including the UK and US pages.

For athletes, both blends contain BPC-157, named under S0, and TB-500, named under S2 of the WADA Prohibited List, so both blends contain substances prohibited at all times ^[15].

We track prices for the individual ingredients: GHK-Cu prices, BPC-157 prices, TB-500 prices and KPV prices. Blends are usually listed under their main ingredient. To compare a blend with separate vials, work out the price per milligram of each peptide. Our guide to peptide prices explains how.