KLOW vs GLOW vs Wolverine: What's Actually in Each Blend, and What the Evidence Covers

Three names, four peptides

KLOW, GLOW and Wolverine are not drugs. They are names sellers give to pre-mixed vials of peptides that are also sold one at a time. Mixing them saves a buyer from reconstituting several vials, and that is the whole idea. What the name does not do is tell you, reliably, what is inside.

These are the compositions stated on the listings we read on September 26, 2026. As everywhere on this site, we describe listings but do not name or link to any seller.

The Wolverine name is a good example of the problem. A 2026 preprint on BPC-157 uses "Wolverine peptide" for BPC-157 on its own, while blend listings use it for BPC-157 with TB-500, and at least one guide applies it to all four KLOW ingredients. Someone who reads "Wolverine" in a forum post cannot know which of the three was meant.

Even the ingredient names wobble. Our TB-500 entry describes TB-500 as a shortened synthetic relative of thymosin beta-4 that shares its actin-binding motif. Some blend listings instead describe their "TB-500" as full-length thymosin beta-4, a 43-amino-acid protein. Those are different molecules sold under one name.

The four components and what each has been tested for

Every evidence grade below comes from our dataset and follows the rubric on our methodology page. Statuses are as of September 26, 2026.

BPC-157

BPC-157 is a 15-amino-acid fragment of a protein found in human gastric juice, studied mostly in rats for tissue repair. The human record is thin. A 2025 pilot gave intravenous BPC-157 to two people who had used it before; the infusions were tolerated, no side effects were reported, and the tested markers of heart, liver, kidney and thyroid function and blood glucose did not change ¹. A 2021 chart review of knee injections is the only human efficacy report, and it had no control group (more on it below) ².

TB-500

No human trial has tested TB-500 as sold. The human studies are of thymosin beta-4, the natural protein TB-500 is modeled on. One gave intravenous thymosin beta-4 to healthy volunteers in four cohorts of ten, first as a single dose and then daily for 14 days, to look at safety ³. Another, run across ten European sites, tested thymosin beta-4 applied to venous leg ulcers ⁴. Neither says anything direct about injecting TB-500 for a strained tendon.

GHK-Cu

GHK-Cu is a copper complex of a three-amino-acid peptide, and the human work on it is about skin. In a small trial after carbon dioxide laser resurfacing, 13 patients completed the study; all of them improved on wrinkles and overall skin quality, with no difference between the treatment groups, although patients rated their skin quality higher with GHK-Cu (P = .04) ⁵. None of the human studies on our GHK-Cu entry tested an injection, which is how blends are used.

KPV

KPV is lysine-proline-valine, the last three amino acids of alpha-melanocyte-stimulating hormone. Its evidence comes from mice. Nanomolar amounts blocked two inflammatory signaling pathways (NF-kappaB and MAP kinase) in gut cells and reduced inflammation in two chemically induced models of colitis ⁶, and it was anti-inflammatory in two further mouse models of inflammatory bowel disease ⁷. It has not been tested in people for anything.

Has any blend been studied?

PubMed's search service was returning errors on September 26, 2026, so we searched Europe PMC, which indexes PubMed, for every pairing of these four peptides. It returned 31 distinct records. Most were reviews, commentaries or preprints. Two report giving a combination to anyone, and both involve only BPC-157 with TB-500 or its parent protein.

The first is a 2026 rat study. Thirty-two rats had an Achilles tendon cut and repaired, then received BPC-157, TB-500, both, or nothing, injected into the abdomen daily for four weeks. Compared with untreated rats, only the TB-500 group showed a statistically significant gain in the load the tendon could bear before breaking. The combination group scored significantly better on one tissue-structure scale, and BPC-157 alone did not reach significance on the overall scores ⁸. The doses were set per kilogram of body weight, not taken from a fixed-ratio vial, and the study tested neither GHK-Cu nor KPV.

The second is the 2021 chart review of knee injections at a single clinic. Of 16 patients reached by phone, 12 had received BPC-157 alone and 4 had received separate injections of BPC-157 and thymosin beta-4; 3 of those 4 reported significant relief ². There was no control group, the outcome was recalled pain over the phone, and four patients cannot establish anything about a combination.

Nothing we found has tested the three-peptide GLOW mix or the four-peptide KLOW mix, in people or in animals (as of September 26, 2026). We also found no published data on how these peptides behave when mixed and stored together in one vial.

What a fixed ratio does to the math

A blend locks its ingredients together. However much water goes into a KLOW vial, every draw contains GHK-Cu, BPC-157, TB-500 and KPV in the same 5 : 1 : 1 : 1 proportion by mass. Water changes how much of everything a draw holds. It never changes the ratio.

Here is the arithmetic for one example, 80 mg dissolved in 2 mL. That makes 40 mg of total peptide per mL: 25 mg/mL of GHK-Cu and 5 mg/mL each of the other three. A 10-unit mark on a 100-unit insulin syringe is 0.1 mL, so it holds 2.5 mg of GHK-Cu and 0.5 mg each of BPC-157, TB-500 and KPV. Double the water and the same mark holds half as much of all four.

Three things follow. First, you cannot take less of one ingredient without taking less of all of them. Second, if a vial is one of the listings that reverses GHK-Cu and BPC-157, the same draw holds five times the BPC-157 and a fifth of the GHK-Cu, with nothing on a nickname to warn you. Third, none of these amounts has been tested in people, alone or together, so the math tells you what a draw contains, not whether it is a sensible amount. For single-peptide arithmetic, our reconstitution calculator does the same sums.

Where each component stands legally, as of September 26, 2026

No component of these blends is an FDA-approved drug, and no blend is either. On July 23, 2026, the FDA's Pharmacy Compounding Advisory Committee voted 8 to 6, with one abstention, to recommend BPC-157, TB-500 and KPV for the 503A bulks list, the list of substances pharmacies may compound from, against the advice of FDA staff ⁹. The FDA has not acted on those votes; our PCAC hub explains what they would and would not change. GHK-Cu for routes other than injection is back in the category the FDA uses for substances under evaluation after a nominator clarified its nomination on May 5, 2026, and the agency says it intends to put GHK-Cu before the committee by the end of February 2027 ¹⁰.

Labelling a blend "research use only" does not change what it is when it is marketed for people. The FDA made that point in its December 2024 warning letters to online sellers of peptides labelled that way ¹¹.

For athletes, all three blends contain at least one substance the World Anti-Doping Agency names. The 2026 Prohibited List names BPC-157 under section S0 and TB-500 under section S2.3. GHK-Cu and KPV are not named, but the S0 catch-all can cover substances with no current regulatory approval ¹².

What this adds up to

A blend combines four compounds with four different evidence bases, none of them strong for injury recovery in people. Two of them have human data only for a related molecule or a different route. Two small reports describe giving BPC-157 with TB-500 or thymosin beta-4 together. Nothing has tested the mixes sold as GLOW or KLOW. The label on the vial is a nickname, the composition behind the nickname varies between sellers, and a fixed ratio means whatever is in the vial arrives in every draw together.

If you are trying to understand any one of these compounds, start with its encyclopedia entry, where each study is listed with what it actually measured.

Frequently asked questions

What is the difference between KLOW and GLOW?

KLOW adds 10 mg of KPV to the GLOW mix. The most common listings describe GLOW as GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg (70 mg in total) and KLOW as the same plus KPV (80 mg in total).

What is in the Wolverine stack?

Most listings describe it as BPC-157 and TB-500, 10 mg each. The name is not fixed: it is also used for BPC-157 alone and for the four-peptide KLOW mix.

Has KLOW or GLOW ever been studied?

No study of either mix, in people or animals, turned up in our search (as of September 26, 2026). The only reports of any combination being given are a 2026 rat study of BPC-157 with TB-500 and 4 patients in a 2021 uncontrolled chart review who received BPC-157 and thymosin beta-4.

Is TB-500 the same as thymosin beta-4?

Not necessarily. Our TB-500 entry describes TB-500 as a shortened synthetic relative of thymosin beta-4, but some blend listings describe their TB-500 as full-length thymosin beta-4. The human trials were of thymosin beta-4.

Can you change the amount of one peptide in a blend?

No. A blend fixes the ratio by mass, so adding more or less water changes the amount of every ingredient in a draw together.

Are these blends legal?

None of the four components, and no blend, is FDA-approved (as of September 26, 2026). The FDA's advisory committee voted to recommend BPC-157, TB-500 and KPV for the compounding list in July 2026, and the FDA has not acted. All three blends contain substances named on WADA's 2026 Prohibited List.

Related on Grey Peptides

• BPC-157 encyclopedia entry
• TB-500 encyclopedia entry
• GHK-Cu encyclopedia entry
• KPV encyclopedia entry
• Thymosin beta-4 encyclopedia entry
• The July 2026 compounding committee votes
• How to verify a peptide: COAs and lab testing
• Reconstitution calculator

Sources

1. Lee, E. et al. (2025). Safety of intravenous infusion of BPC157 in humans: a pilot study. Alternative Therapies in Health and Medicine, 31(5), 20–24. PMID: 40131143
2. Lee, E. et al. (2021). Intra-articular injection of BPC 157 for multiple types of knee pain. Alternative Therapies in Health and Medicine, 27(4), 8–13. PMID: 34324435
3. Ruff, D. et al. (2010). A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Annals of the New York Academy of Sciences, 1194, 223–229. PMID: 20536472
4. Guarnera, G. et al. (2007). Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability, and enhancement on healing. Annals of the New York Academy of Sciences, 1112, 407–412. PMID: 17495250
5. Miller, T. R. et al. (2006). Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Archives of Facial Plastic Surgery, 8(4), 252–259. PMID: 16847171
6. Dalmasso, G. et al. (2008). PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology, 134(1), 166–178. PMID: 18061177
7. Kannengiesser, K. et al. (2008). Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflammatory Bowel Diseases, 14(3), 324–331. PMID: 18092346
8. Biçer, O. et al. (2026). Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: a histopathological and biomechanical study. Joint Diseases and Related Surgery, 37(3), 822–837. PMID: 42542926
9. U.S. Food and Drug Administration (2026). July 23–24, 2026 meeting of the Pharmacy Compounding Advisory Committee. Page current as of August 6, 2026; re-read September 26, 2026. FDA meeting page
10. U.S. Food and Drug Administration (May 14, 2026). Bulk drug substances nominated for use in compounding under section 503A: categories. Updated May 14, 2026; re-read September 26, 2026. FDA category list (PDF)
11. U.S. Food and Drug Administration (December 10, 2024). Warning letter 694608 to an online seller of peptides labelled for research use only. FDA warning letter
12. World Anti-Doping Agency (2026). The 2026 Prohibited List, in force January 1 to December 31, 2026. Read in full July 16, 2026. WADA

This article is for education. It is not medical or legal advice, and it is not a guide to buying or using any peptide. None of the compounds discussed here is approved for injury recovery.