For laboratory research use only — not for human consumption
Comparison
Copper-binding tripeptide complex · Synthetic thymosin β4 fragment
GHK-Cu is a copper-binding tripeptide complex; TB-500 is a synthetic thymosin β4 fragment. They are compared here because they appear together in research catalogues, not because they are interchangeable. GHK-Cu is studied in copper-peptide & matrix-signalling research, TB-500 in actin-signalling & fragment-peptide research. This page sets out structure, identifiers and research context only; it makes no human-use, dosing, or therapeutic claim. Both are supplied for in-vitro laboratory research use only.
| GHK-Cu | TB-500 | |
|---|---|---|
| Class | Copper-binding tripeptide complex | Synthetic thymosin β4 fragment |
| Research area | Copper-peptide & matrix-signalling research | Actin-signalling & fragment-peptide research |
| CAS number | 49557-75-7 | 77591-33-4 |
| Molecular formula | C14H22CuN6O4 | C212H350N56O78S |
| Sequence | Gly-His-Lys · Cu(II) | — |
| HPLC purity | 99.72% | 99.02% |
The two sit in different structural families. GHK-Cu is classified as a copper-binding tripeptide complex, while TB-500 is a synthetic thymosin β4 fragment. That difference is the substantive one: it means the two are not variants of a single scaffold, and any protocol that substitutes one for the other is changing the compound class under study, not simply swapping a reagent of the same type.
Their research framing also diverges. GHK-Cu is catalogued under copper-peptide & matrix-signalling research, whereas TB-500 is catalogued under actin-signalling & fragment-peptide research. Investigators therefore tend to encounter the two in separate literatures, and any observation reported for one should not be read across to the other — findings belong to the studies and models that produced them.
Only one of the two is catalogued here with an explicit amino-acid sequence. GHK-Cu is listed as Gly-His-Lys · Cu(II), while TB-500 is identified by molecular formula and CAS number instead — the usual convention for larger or heavily modified peptides, where the formula and the mass-spectrometry result carry the identity rather than a written residue string.
The molecular formulae differ accordingly — GHK-Cu is C14H22CuN6O4 and TB-500 is C212H350N56O78S — with TB-500 being the larger molecule of the two and GHK-Cu the more compact. Molecular size is worth noting when planning reconstitution and storage, since molar concentration for a given vial mass is not the same across the two.
On characterisation, the current batches report 99.72% HPLC purity for GHK-Cu and 99.02% for TB-500 — 0.70 percentage points apart. These are batch-specific figures rather than a fixed property of either compound, so the Certificate of Analysis published against the batch actually received is the value that should be recorded in a method section, not the figure quoted on this page.
The two sit in distinct research areas — copper-peptide & matrix-signalling research for GHK-Cu, actin-signalling & fragment-peptide research for TB-500 — so the lists below have little in common. These are areas of scientific study reported in the primary literature, not effects.
These are structurally distinct compounds studied in different contexts, so they are complements rather than substitutes. GHK-Cu is the appropriate reference reagent where the question concerns copper-peptide & matrix-signalling research and the copper-binding tripeptide complex scaffold; TB-500 is appropriate where the question concerns actin-signalling & fragment-peptide research and the synthetic thymosin β4 fragment scaffold.
Whichever is selected, the practical criteria are the same and are documentary rather than comparative: that the CAS number and molecular formula match what the protocol specifies, that a current per-batch Certificate of Analysis is on file, and that handling and storage follow the notes published on each monograph. Nothing on this page ranks one compound above the other, and neither is characterised for, or supplied for, any use outside in-vitro laboratory research.
Each compound has its own research monograph with the complete overview, studied-in list and laboratory handling notes, and a product page carrying the current batch COA.
Copper-binding tripeptide complex · CAS 49557-75-7
The tripeptide was first isolated from human plasma fractions in the 1970s during work on factors that differed between plasma from younger and older donors, and the copper-binding behaviour was characterised shortly afterwards.
Synthetic thymosin β4 fragment · CAS 77591-33-4
Thymosin β4 itself was identified in thymic extracts in the mid-1960s and later reclassified once its principal biochemical role — sequestering monomeric G-actin and thereby buffering the pool available for filament assembly — was characterised.
Both compounds are supplied strictly for in-vitro laboratory research use only. Not for human or veterinary use. This comparison is structural and contextual and does not constitute advice on use.