Posting a negative result because this subforum needs more of them. Mid-30s, noticed the usual heavier shed I get every spring and got it into my head that a copper peptide topical might blunt it. This is just what happened to me.
I used a GHK-Cu serum consistently for about ten weeks. I took monthly photos in the same light because I know how unreliable memory is here. Honestly? The shed ran its normal course and tapered on roughly the same schedule it always does. My scalp felt a little less dry, which I'll grant, but density-wise I couldn't see a difference in the photos and neither could my partner when I asked without priming them.
So, no effect on the thing I cared about, for me. I know seasonal shedding is self-limiting anyway, which makes this a hard endpoint to judge. The skin-feel change was real but that wasn't my goal. Sharing so the next person searching doesn't only find the success stories.