FREQUENTLY ASKED
Questions, Answered Against the Record
Twelve questions people actually search for, answered from the seventeen sources indexed on this site — including the answers that are simply "nobody has measured that".
What does BPC-157 do in the body?
In animals, the effect traced most consistently is angiogenesis — the growth of new blood vessels. A 2017 study reported that BPC157 up-regulates the VEGFR2 receptor and promotes its internalisation, with downstream VEGFR2-Akt-eNOS signalling, raising vessel density in a chick membrane and in cultured human endothelial cells and speeding blood-flow recovery in a rat hindlimb [4].
Alongside that, rodent work reports faster healing of a transected Achilles tendon [6] and of gastric ulcers [5], and a review describes modulation of serotonin and dopamine systems through the brain-gut axis [7].
What it does in a human body is largely unmeasured. As of 2025 only three small pilot studies existed, with rigorous trials lacking [2], and the one first-in-human safety pilot in this index involved two people [1].
Is BPC-157 a growth hormone?
No. BPC-157 is a fifteen-amino-acid peptide derived from a partial sequence of a protein found in gastric juice; human growth hormone is a 191-amino-acid protein made by the pituitary gland. They are different molecules with different origins and different receptors.
The confusion has a real root. In cultured tendon fibroblasts, BPC-157 increased growth-hormone-receptor signalling, which is part of how it is thought to encourage tissue growth. Sensitising a receptor to a hormone is not the same as being that hormone, and no study in this index reports BPC-157 raising growth hormone levels.
Common online claims that it builds muscle, drives weight loss or raises testosterone are not supported by the published evidence indexed here.
Does BPC-157 work immediately?
There is no human efficacy trial to answer this from, so any timeline is either an animal observation or an anecdote.
The pharmacokinetic picture argues against the peptide itself lingering: in rats and beagle dogs, BPC157 showed an elimination half-life under thirty minutes and rapid breakdown into small fragments entering ordinary amino-acid metabolism [3]. Any sustained effect would have to come from downstream signalling rather than from the molecule remaining present.
In research-use communities, people frequently report improvement in tendon, ligament and joint problems within the first one to three weeks, and easier gut symptoms within one to two. Those accounts are anecdotal, not clinical evidence, they carry no dose here, and no controlled human study has tested them.
Does BPC-157 damage the liver?
No published finding in this index reports liver damage from BPC-157, and the one relevant human measurement points the other way — but it is very small.
In a 2025 first-in-human safety pilot, intravenous BPC157 at up to 20 mg in two healthy adults was well tolerated, with no observed adverse events and no measurable changes in cardiac, hepatic, renal, thyroid or glucose biomarkers [1]. Two participants, no control group, single occasion.
That is not evidence of long-term hepatic safety and should not be read as such. There are no long-term human safety data for this compound at all [2], and because it is distributed through non-regulated channels, what is actually in a given product is unverified — which is its own source of risk independent of the peptide.
What does a GHK-Cu peptide do?
In skin, it stimulates repair and matrix-building activity. GHK-Cu prompts dermal fibroblasts to produce collagen, elastin, glycosaminoglycans and decorin, and rebalances matrix metalloproteinases against their TIMP inhibitors, while the bound copper enables lysyl oxidase cross-linking and superoxide-dismutase-like antioxidant activity [11].
In measured human terms, topical GHK-Cu increased collagen production in 70% of treated women, compared with 50% for vitamin C and 40% for retinoic acid [11], a comparison reproduced in a 2025 review [8]. On the scalp, a six-month randomised trial of a 5-aminolevulinic acid and GHK peptide complex in 45 men raised hair count by 52.6 and 71.5 at two concentrations against 9.6 for placebo (p<0.05) [10].
What it does elsewhere in the body is far less established, and nothing in this index measures it acting on a nerve.
What is GHK-Cu and how does it work?
GHK-Cu is a three-amino-acid peptide — glycine, histidine, lysine — chelated to a copper(II) ion in a one-to-one complex. The sequence occurs naturally within type I collagen and in the matrix protein SPARC, and circulating levels fall with age, from roughly 200 ng/mL at twenty to roughly 80 ng/mL by sixty [11].
It is described as working two ways at once: delivering copper where it is needed, and signalling in its own right. The broadest claim is transcriptomic — gene-expression analysis reports GHK altering about 31.2% of human genes at a 50%-or-greater change threshold, 59% up and 41% down, including strong stimulation of the ubiquitin-proteasome system and of DNA-repair and antioxidant gene sets [9].
That analysis is largely database-derived and awaits protein-level confirmation in living tissue, and the popular "about 4,000 genes" figure is an extrapolation from it rather than a measurement.
Is GHK-Cu peptide really anti-aging?
For skin appearance, the topical evidence is real but modest in scale. Placebo-controlled work reports improvements in skin laxity, clarity, fine lines, wrinkle depth and density, alongside the 70% procollagen figure [11][8].
For systemic ageing, the claims outrun the measurements. The gene-expression case rests on database analysis needing in vivo confirmation [9], a large share of the foundational literature comes from a single investigator and colleagues, and there is no validated human pharmacokinetic data for any non-topical route.
There is also a practical ceiling. The free peptide has poor stratum-corneum permeability, quantified as a clogP of -2.24, which is why formulation strategies such as palmitoylation and microneedle pretreatment are being investigated at all [8]. A compound that struggles to cross skin is not a general-purpose anti-ageing agent for the rest of the body.
What is the difference between GHK and GHK-Cu?
GHK is the bare tripeptide. GHK-Cu is that same tripeptide holding a copper(II) ion, coordinated through the histidine imidazole nitrogen, the glycine alpha-amino nitrogen and the deprotonated glycine-histidine amide nitrogen, leaving the lysine side chain free.
The difference is not cosmetic. Most of the documented tissue-remodelling activity depends on copper being properly bound, and plain GHK without copper does not reproduce key effects in cell studies. Intact GHK-Cu also binds copper tightly enough to stop it acting as a pro-oxidant; if the complex is broken apart — for instance by low-pH ascorbic acid or exfoliating acids in the same step — that protection is lost and both products can be wasted [8].
The two names are frequently conflated in the literature, so which form a given study used changes what that study actually shows.
What is TB-500?
TB-500 is a synthetic seven-amino-acid peptide, Ac-LKKTETQ, corresponding to residues 17 to 23 of thymosin beta-4 — the conserved actin-binding motif of the beta-thymosins. It is sold for laboratory research use, has no approved therapeutic indication, and is prohibited in sport by WADA.
The crucial distinction is size. Thymosin beta-4 is a 43-amino-acid protein of roughly 4,963 daltons; TB-500 is roughly 889 daltons. Almost all the encouraging efficacy research, including the rat stroke study [14] and the human Phase 1 safety study [16], used the full-length protein rather than the fragment.
Whether the isolated seven-mer reproduces the parent protein's effects has not been established in any controlled human trial, so results from one should not be read as results for the other.
What does TB-500 stand for and what does TB stand for in TB-500?
TB stands for thymosin beta. The name points at thymosin beta-4, the 43-amino-acid protein whose actin-binding region the peptide reproduces.
The numeric part is a supplier and research designation rather than a scientific descriptor; nothing in the literature indexed here documents a meaning for it. In research and veterinary contexts the same material also appears as TB1000, and in the analytical and anti-doping literature it is identified by its sequence, Ac-LKKTETQ, rather than by the trade name.
This matters more than a naming curiosity usually would, because the name borrows the parent protein's identity while the product is a fragment of it — which is exactly how the parent protein's research results end up attached to a different molecule.
What is TB-500 used for in research?
In the published literature, the work is mostly done with full-length thymosin beta-4 rather than the fragment, and it clusters around cell migration and injury repair.
Structural work established that thymosin beta-4 sequesters monomeric G-actin one-to-one by capping both ends of the monomer, using the WH2 motif [17]. A 2012 review consolidates the downstream account — cell mobilisation and migration, reduced myofibroblast numbers and therefore less scarring, limits on apoptosis and inflammation after injury, and angiogenesis — and presents it as the rationale for trials in dermal wounds, corneal injury, and heart and central-nervous-system repair [15].
The one neurological efficacy result in this index is a rat study: intraperitoneal thymosin beta-4 after an embolic stroke improved neurological function at 2 and 12 mg/kg from day 14 through day 56 (p<0.05), with no significant benefit at 18 mg/kg [14]. Rat, parent protein, brain rather than peripheral nerve.
Does TB-500 work for muscle tears and recovery from exercise?
No completed controlled human trial has tested the TB-500 fragment for muscle injury or exercise recovery, so there is no evidence-based answer in either direction.
What exists is a 2026 sports-medicine review concluding that unapproved peptides of this class show favourable tissue-repair outcomes in animal models while rigorous human safety data are scarce, with real potential for serious harm and little regulatory oversight [13]. Preclinical work also supplies a direct counter-example: in dystrophin-deficient mice, long-term thymosin beta-4 increased the number of regenerating muscle fibres but did not improve muscle strength, cardiac function or fibrosis — more repair activity without better function.
In research-use communities, faster recovery from tendon, ligament and muscle injuries is the most commonly reported reason for using it, with timelines varying widely. Those reports are anecdotal, not clinical evidence, and no dose is given here. TB-500 is also prohibited in tested sport, with published detection methods.