What did the experiments measure?
A useful comparison starts by naming the result. The subjects and measurements here differ too much for a healing league table.
Subjects and results
The following findings come from separate experiments. The entries name the tested material rather than transferring results between related peptides.
| Tested material | Subject | Measured change |
|---|---|---|
| GHK | Human cell-data analysis | Higher and lower gene expression |
| BPC-157 | Cells, chick membranes and rats | Vessel growth and recovering blood flow |
| Full thymosin beta-4 | Rat skin wounds | New skin coverage and contraction |
| GHK with 5-aminolevulinic acid | Men with inherited hair loss | Higher hair counts than placebo |
| GLOW | No controlled blend trial | Combined benefit remains unmeasured |
I won’t award a winner on measurements this different. The most dramatic molecular count and the most direct human result answer different questions. Their size alone cannot put them on the same scale.
Function after injury
The mouse cardiac experiment measured heart function as well as cell migration and survival. The rat stroke experiment measured neurological function. Those outcomes matter because they ask whether experimental tissue changes accompanied something the organ or animal could do.
I value functional outcomes while recognising the limits of animal studies. They identify the sort of question a human injury trial would need to answer: useful movement, strength or function, compared with appropriate care and followed long enough to see whether improvement lasts.
Skin appearance and hair counts can be worthwhile outcomes in their own settings. They leave those injury questions open. The GHK-Cu essay gives the human cosmetic findings room without asking them to explain whole-body repair.
Combination trial comparisons
The hair trial offers a useful example of a combination actually being put to a comparison. Its GHK-containing formulation was tested against placebo. The result supports further interest in that formulation while leaving the ingredients' separate contributions unresolved.
GLOW has the earlier task still ahead of it: a controlled experiment on the completed mixture. A longer ingredient list increases the number of questions about attribution and interaction. It cannot calculate an extra benefit.
For the safety observations, the distinction changes again. A study of healthy volunteers can help investigate tolerability without establishing that an injured person recovers better. Calling all of these findings “positive results” throws away too much information.