Compound Notes · Jul 28, 2026
TB-500 vs GHK-Cu: The Largest and Smallest in the Catalogue
These two sit at opposite ends of this catalogue by size, and the gap explains most of the practical differences between them.
| TB-500 | GHK-Cu | |
|---|---|---|
| Molecular formula | C212H350N56O78S | C14H24N6O4Cu |
| Molar mass | 4,963.44 g/mol | 401.94 g/mol |
| CAS | 77591-33-4 | 89030-95-5 |
| Class | large peptide | tripeptide-copper complex |
TB-500 is roughly twelve times heavier. GHK-Cu is three amino acids and a copper ion. TB-500 is a long chain containing sulfur.
Why the size gap drives the price gap
A tripeptide is three coupling steps. A chain the length of TB-500 is dozens. Each step is efficient but imperfect, and the failures accumulate as deletion sequences that are chemically near-identical to the target and correspondingly hard to separate.
That is the entire reason a gram of one costs a fraction of a gram of the other, and why the purity spread between suppliers is much wider for TB-500 than for GHK-Cu. A 99% figure on a tripeptide is close to table stakes. The same figure on a 40-plus residue chain represents real purification work.
Different failure modes
TB-500 contains sulfur, so oxidation is a live degradation route alongside hydrolysis and aggregation. Long chains also have more structure to lose, making it less tolerant of freeze-thaw cycling and agitation.
GHK-Cu is short enough that chain degradation is barely a concern. Its vulnerability is the copper: the metal can be lost or displaced, and chelators will strip it. It is also the one compound here you can partly check by eye, since copper(II) complexes are blue and a colourless GHK-Cu solution is wrong.
Testing status
GHK-Cu lot KP-GHK--2609 carries an independent certificate from Krause Analytical reporting 99.90%. TB-500 has no analysed lot at present, which for a compound of that length is exactly the case where a certificate would tell you most. See the lab results page.
Related
- TB-500 research primer
- GHK-Cu research primer
- BPC-157 vs GHK-Cu
- Why purity figures differ between suppliers
Supplied as laboratory reagents for research use only.
Compounds covered here
Supplied as a laboratory reagent for research use only. Not for human or veterinary use.
Related reading
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- Ipamorelin vs CJC-1295: Two Different Molecule Classes
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