Four different origins
"Repair peptides" is a catalogue heading, not a pharmacological class. One of these is a fragment of a stomach protein, one is a full-length human protein, one is a three-residue copper complex found in blood plasma, and one is the tail end of a pigmentation hormone. The honest comparison is by what each is, what has been tested, and in what.
Side by side
| Compound | What it is | Models in the cited papers | Human evidence |
|---|---|---|---|
| BPC-157 | A 15-residue fragment of a protein found in gastric juice, studied since the 1990s largely by one group in Zagreb | Rat tendon fibroblasts in culture; rodent models of gastrointestinal injury, tendon and ligament injury | No completed human efficacy trial has been published. As an unapproved substance it falls under WADA's non-approved category for athletes. |
| TB-500 (thymosin β4) | The 43-residue actin-sequestering protein present in most human tissues; the formula and mass on our specification (C212H350N56O78S, 4963 g/mol) are those of the full-length sequence | Rat full-thickness skin wounds; mouse myocardial infarction; cell migration assays | A thymosin β4 eye drop has reached late-stage clinical trials for corneal conditions under a different developer. No approval anywhere. |
| GHK-Cu | Gly-His-Lys complexed with copper(II), isolated from human plasma in 1973; plasma levels reported to decline with age | Human fibroblast cultures (collagen synthesis); gene-expression datasets; skin studies | Decades of use in cosmetics at low concentrations. No drug approval. |
| KPV | Lys-Pro-Val, the C-terminal tripeptide of α-MSH; retains the anti-inflammatory activity of the parent without acting on pigmentation | Mouse colitis models; intestinal epithelial cell culture (PepT1 uptake) | Preclinical only. |
What the cited studies found
BPC-157
Chang and colleagues (2011) grew fibroblasts from rat Achilles tendon and found that BPC-157 increased their outgrowth, survival and migration, with the FAK–paxillin pathway implicated. The Sikiric group's reviews (2011, 2016) collect rodent work across gastrointestinal, vascular and nervous-system injury. What the literature does not contain is a controlled human trial, which is the single most important fact about this compound and the reason we state it plainly.
Thymosin β4
Malinda and colleagues (1999) found that thymosin β4 accelerated closure of full-thickness wounds in rats, with more re-epithelialisation and collagen deposition. Bock-Marquette and colleagues (2004, Nature) showed it activates integrin-linked kinase in heart muscle cells and improved cardiac function after coronary ligation in mice. Goldstein's 2012 review covers its basic biology as an actin-binding protein and the early clinical programmes.
GHK-Cu
Maquart and colleagues (1988) showed the copper complex stimulated collagen synthesis in fibroblast cultures at nanomolar concentrations, the paper that started the cosmetic interest. Pickart's later reviews (2015, 2018) compare GHK against large gene-expression datasets and argue for a broad regulatory effect; those are analyses of existing data rather than new trials.
KPV
Dalmasso and colleagues (2008, Gastroenterology) showed KPV is carried into intestinal epithelial cells by the PepT1 transporter and reduced inflammation in two mouse colitis models. Brzoska and colleagues (2008) reviewed how α-MSH and its C-terminal tripeptide act on inflammation independently of pigmentation.
Why the blends exist
BPC-157 + TB-500 combines the two most requested compounds on this list in one vial at a 1:1 ratio, and GHK-Cu + BPC-157 + TB-500 + KPV adds the copper peptide and KPV. A blend is assayed component by component on its certificate, so it carries a content figure for each peptide and no single purity number. The rationale for combining them comes from the separate literatures above, not from trials of the combination.
Handling notes for this group
- Thymosin β4 contains methionine, which oxidises in solution; keep reconstituted material dark and capped.
- GHK-Cu is supplied as the copper complex and its blue colour is the complex itself. Keep it away from chelating buffers and reducing agents, and do not combine it in one solution with anything that would strip the copper.
- BPC-157 and KPV carry no oxidation-prone residues; standard cold, dark storage applies.
- All four are lyophilised and stable for years at −20°C. Details by form are on the storage guide.
In our catalog
BPC-157, TB-500, GHK-Cu and KPV, plus the two blends above. Each product page carries the references summarised here with PubMed links and the certificate for the lot in stock where one exists.