Both are tissue-repair peptides but they work on different systems. GHK-Cu is a copper-binding tripeptide best known for skin and hair research. BPC-157 is a 15-amino-acid gastric pentadecapeptide used for tendon, ligament and GI research.
GHK-Cu
BPC-157
Length
3 aa + Cu²⁺
15 aa
Molecular weight
~340 Da (peptide) / 403 Da (complex)
~1419 Da
Primary research target
Skin, hair, wound healing
Tendon, GI, ligament
Route
Topical, subcut, or injection
Subcut or oral
Typical dose
1-5 mg subcut
250-500 mcg subcut
Copper requirement
Yes - Cu²⁺ binding essential
No copper
Most common QC failure
GHK only - missing copper complex
Under-fill with mannitol
Identity (LC-MS) expected mass
~403 Da
~1419 Da
Verdict
GHK-Cu is for skin and hair, BPC-157 is for tendons and gut. The biggest GHK-Cu failure mode is missing copper (vendor ships GHK at 340 Da instead of GHK-Cu at 403 Da). BPC-157's failure mode is under-fill. Different molecules, different tests, both worth verifying.
Frequently asked questions
Are they stacked?
Sometimes - different mechanisms, no known interaction. Topical GHK-Cu + subcut BPC-157 is common in recovery research.
Can LabDoc confirm the copper complex on GHK-Cu?
Yes - LC-MS resolves the 403 Da copper-bound mass cleanly vs the 340 Da naked tripeptide.