RECOVERY & TISSUE REPAIR / FAQ
Questions From the Literature
Direct, citation-anchored answers to the questions readers most often bring to these three recovery peptides.
What does BPC-157 do in the body?
In animal models, BPC-157 is described as a cytoprotective and regenerative peptide. Its repair effects are tied most consistently to angiogenesis — encouraging the growth of new blood vessels into injured tissue by making blood-vessel cells more responsive to the VEGFR2 vessel-growth signal [4]. It has accelerated healing in rat models of gastric ulcers [5] and transected tendon [6], and it is described as modulating brain-gut signaling pathways including serotonin and dopamine systems [7]. Crucially, almost all of this is preclinical; human evidence is limited to three small pilot studies [2].
Is BPC-157 a growth hormone?
No. BPC-157 is not a growth hormone and is not growth hormone in any form. It is a synthetic fifteen-amino-acid peptide derived from a protein in gastric juice. There is a connection point that sometimes causes confusion: in tendon fibroblasts, BPC-157 has been reported to sensitize the growth-hormone receptor, which may amplify the effect of the body's own growth hormone [7]. Making a receptor more responsive is not the same as being a growth hormone. BPC-157 does not replace or act as growth hormone itself.
Does BPC-157 work immediately, and how long does it stay in the body?
The peptide clears from the bloodstream quickly. Pharmacokinetic work in rats and beagle dogs found a very short elimination half-life — under 30 minutes — with rapid breakdown into small fragments that re-enter normal amino-acid metabolism [3]. A short half-life means the intact peptide does not linger long after dosing. Whether any healing effect appears quickly is a separate question; the published healing data are from animal studies measured over days to weeks, not immediate human outcomes [6]. This site does not advise on use or timing.
Does BPC-157 damage the liver?
The available data do not show liver harm, but the data are very thin. In the 2025 first-in-human intravenous safety pilot, BPC-157 up to 20 mg in two healthy adults produced no measurable changes in hepatic, cardiac, renal, thyroid or glucose biomarkers and no adverse events [1]. That is reassuring, but it is two people in a safety pilot, not a liver-safety study. The broader literature stresses that without long-term, large-sample human data, the overall safety profile remains genuinely unknown [2]. Nothing here is medical advice.
What is TB-500, and what does the TB stand for?
"TB" refers to thymosin beta — specifically thymosin beta-4 (Tβ4), the natural protein TB-500 is derived from. TB-500 itself is a synthetic seven-amino-acid fragment, Ac-LKKTETQ, corresponding to the actin-binding region (residues 17-23) of that protein [12]. An important nuance: in commerce and anti-doping science, "TB-500" means the short fragment, but most published efficacy research uses the full-length Tβ4 protein, which is about five times larger [8]. The name points at a fragment while much of its published reputation rests on the whole protein.
What is TB-500 used for in research?
In research, TB-500 (and more often full-length thymosin beta-4) is studied for tissue repair driven by actin regulation: cell migration, new blood-vessel growth, reduced scarring, and anti-inflammatory signaling, with models in dermal wounds, cornea, heart and CNS [10]. A human Phase 1 study of full-length Tβ4 in 40 volunteers focused on safety and pharmacokinetics [11], and a rat study examined neurological recovery after stroke [9]. There are no completed controlled clinical trials of the TB-500 fragment itself for any indication [8].
Does TB-500 work for muscle tears and recovery from exercise?
There is no controlled human evidence that the TB-500 fragment helps muscle tears or exercise recovery. The mechanistic rationale comes from thymosin beta-4's role in cell migration and repair [10], but a 2026 Sports Medicine review of unapproved peptides for musculoskeletal injury and athletic performance concluded that favorable animal results have not been matched by rigorous human safety or efficacy data, and that these compounds operate largely outside regulatory oversight [8]. Notably, in a muscular-dystrophy mouse model chronic Tβ4 increased regenerating fibers but did not improve muscle strength [10]. TB-500 is also banned in sport [8].
What does GHK-Cu do, and how does it work?
GHK-Cu is a copper-carrying tripeptide that does two things simultaneously: it ferries copper into tissue and it signals repair. At very low concentrations it tells dermal fibroblasts to synthesize collagen, elastin, glycosaminoglycans and decorin, while rebalancing matrix-degrading enzymes against their inhibitors; the copper itself enables collagen and elastin cross-linking and an antioxidant action [16]. At the gene level it shifts expression of roughly 31.2% of human genes (at a 50%-or-greater change threshold) toward repair, DNA-repair and antioxidant programs [14]. Most of its documented human benefit is in topical skin applications [13].
Is GHK-Cu peptide really anti-aging?
There is real, if modest and mostly topical, human evidence for skin benefits. Topical GHK-Cu increased collagen production in about 70% of treated women, outperforming vitamin C (50%) and retinoic acid (40%) in the same review, and placebo-controlled improvements in skin laxity, clarity, fine lines and wrinkle depth are documented [16]. Two honest caveats belong with that: the dramatic "~4,000 genes" claim is an extrapolation from a verified figure of roughly 2,100 genes at the measured threshold [14], and the peptide penetrates intact skin poorly, limiting how much reaches the dermis without delivery aids [13]. Systemic anti-aging use is unproven.
What is the difference between GHK and GHK-Cu?
GHK is the bare tripeptide glycyl-histidyl-lysine; GHK-Cu is that same tripeptide chelated to a copper(II) ion. The distinction matters — copper coordination is required for most of GHK's reported bioactivities, so the form used in a given study is not trivial, and the two are frequently conflated in secondary sources [16]. When research describes collagen stimulation, cross-linking and antioxidant effects, it is generally the copper complex (GHK-Cu) doing the work.
Are these peptides legal?
The legal picture differs across the three. GHK-Cu as a topical cosmetic ingredient is legal and widely sold in many jurisdictions. BPC-157 and TB-500 are not approved drugs anywhere, and both are prohibited in sport by WADA — BPC-157 under the S0 non-approved-substances category, TB-500 under prohibited peptide and growth-factor categories [8]. Research-grade supply of these compounds is sold for laboratory use only, not human consumption. Legal status can vary by country, and athletes subject to anti-doping rules should consult their governing body.
What do these peptides have in common?
All three are synthetic peptides studied in the context of recovery and tissue repair. All three have most of their evidence base in preclinical (animal or cell) models. None is an approved medicine for any indication in the United States or European Union. All three are described by their suppliers as for laboratory research use only. The differences lie in their mechanism (angiogenesis for BPC-157, actin-mediated migration for TB-500, matrix synthesis for GHK-Cu), their evidence depth, and their regulatory footing. See the compare page for the side-by-side.