GHK-Cu vs TB-500
GHK-Cu (Copper-binding tripeptide) and TB-500 (Actin-binding peptide fragment) are documented as co-studied in the PeptiDex library. This page puts the two entries side by side on class, molecular weight, half-life, origin, mechanism and studied research areas — every value taken from the entry it belongs to.
Why these two are co-studied
Cross-referenced for research context — not a usage or combination recommendation.
At a glance
| Attribute | GHK-Cu | TB-500 |
|---|---|---|
| Compound class | Copper-binding tripeptide | Actin-binding peptide fragment |
| Research category | Cosmetic & Dermal | Healing & Recovery |
| Length (amino acids) | 3 amino acids | 7 amino acids |
| Molecular weight | 340.4 Da | ~4921 Da (full-length thymosin beta-4); ~889 Da for the Ac-LKKTETQ fragment form |
| Half-life | Not documented | ~2-3 hours (elimination); tissue effects reported to persist for days |
| Origin | GHK is a naturally occurring tripeptide (glycyl-L-histidyl-L-lysine) found in human plasma, with levels reported to decline with age. GHK-Cu is its complex with copper(II) ions and is widely used as a cosmetic ingredient. | TB-500 is a synthetic peptide commonly described as corresponding to the actin-binding domain (a short fragment, often the LKKTETQ region) of Thymosin Beta-4, a naturally occurring 43-amino-acid protein involved in actin regulation. TB-500 is produced synthetically and is not identical to full-length Thymosin Beta-4. |
“Not documented” means the PeptiDex entry records no value for that field. Nothing on this page is estimated, and no figure is carried over from one compound to the other.
How GHK-Cu works
GHK has a high affinity for copper(II) and is understood to act partly as a copper-delivery molecule, facilitating copper transport relevant to enzymatic and remodeling processes. In cell and skin research it has been associated with signaling that influences extracellular-matrix remodeling, collagen and glycosaminoglycan synthesis, and antioxidant and gene-expression effects. Much of this work is from in-vitro and skin studies.
How TB-500 works
Thymosin Beta-4 and its actin-binding fragment are studied for their ability to sequester G-actin and influence actin polymerization, which relates to cell migration. In preclinical models, this activity has been linked to cell migration, angiogenesis and tissue-repair processes. These mechanisms are drawn largely from animal and cell-culture research and are not established in controlled human trials for TB-500 itself.
Mechanistic descriptions reflect published research-literature understanding and are quoted from each compound's own entry. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
Where each one appears in the literature
The research contexts each entry documents. Listing a research area is not a claim of efficacy or a therapeutic indication, and the two lists are not scored against each other.
GHK-Cu
TB-500
What sets each apart
GHK-Cu
GHK-Cu is the most established copper tripeptide in cosmetic use, distinguished from AHK-Cu by its sequence and from repair peptides like BPC-157 by its remodeling and copper-delivery focus.
TB-500
TB-500 is defined by its actin-binding fragment identity, distinguishing it from BPC-157's growth-factor/angiogenesis focus and from copper tripeptides used cosmetically.
Documented together as a research blend
Cross-referenced for research context — not a usage or combination recommendation.
Frequently asked questions
What is GHK-Cu?
GHK-Cu is a complex of the naturally occurring tripeptide GHK (glycyl-L-histidyl-L-lysine) with a copper(II) ion. The GHK sequence is a subfragment of the alpha-2 chain of type I collagen and is present in human plasma, where its level declines with age. It is studied primarily as a copper-delivery and skin-remodeling signal peptide.
What is GHK-Cu studied for?
In research and cosmetic-formulation literature it is studied for collagen and glycosaminoglycan synthesis in dermal fibroblasts, wound-model remodeling, and antioxidant/gene-modulating activity. It is characterized as a signaling peptide rather than a therapeutic drug, and is not FDA-approved for treating any condition.
Why is a higher GHK-Cu concentration not necessarily better?
Research summaries note a biphasic dose response: GHK-Cu stimulates matrix synthesis at low (picomolar to nanomolar) concentrations, but at higher concentrations it can also upregulate matrix-degrading enzymes. This is why most cosmetic formulation guidance centers on the low end of the topical range rather than maximizing concentration.
What is TB-500 and how does it relate to thymosin beta-4?
TB-500 is a research peptide associated with thymosin beta-4 (Tbeta4), a 43-amino-acid actin-binding regulatory peptide. The name TB-500 is used in the research-chemical market for both full-length thymosin beta-4 (MW ~4921 Da) and, in some references, the acetylated active fragment covering residues 17-23 (Ac-LKKTETQ). Buyers should check each vendor's COA, since what is shipped as 'TB-500' varies.
What is TB-500 studied for?
In animal models it is researched for tissue repair, wound healing, angiogenesis, and cell migration, largely through thymosin beta-4's role in sequestering G-actin and regulating the actin cytoskeleton. It has also been examined in cardiac and corneal repair models. Human clinical efficacy has not been established.
What does TB-500's half-life imply for research protocols?
Reported elimination half-life is roughly 2-3 hours, but downstream tissue effects are described as persisting for days through signaling cascades. Because of this, research protocols typically use infrequent dosing (e.g. a few times per week) rather than daily, loading over several weeks before a maintenance phase.
Answers are the ones published on each compound's own PeptiDex entry. They are educational summaries of research-literature context and are not medical advice.