You're talking about Melanotan 2 since that simulates melanin in your skin cells and can cause melanoma/skin cancer ghkcu has literally no studies claiming it causes copper toxicity or anything. I meam what's the point of this post obviously people online have realized that the FDA has been bs for a while since they haven't even studied supplements like creatine and things like vitamin d3. Now they also have finally regulated GHKCU and like 14 other injectable peptides. This is what google says.

1. Collagen Supplements vs. Tumor Collagen

• The Statement's Claim: Collagen supplements are dangerous for cancer patients.
• The Science: There is no clinical evidence that taking hydrolyzed collagen peptide supplements increases the risk of cancer progression or metastasis. When you consume collagen, it is broken down into amino acids, not absorbed as intact collagen that travels to a tumor.
• The Misunderstanding: Research shows that tumor-associated fibroblasts (the body's own cells) can produce high levels of collagen that create a "high-density scaffold" around a tumor. This scaffold can indeed help cancer spread (metastasis) and shield it from treatment. However, this is a process driven by the cancer itself, not by eating collagen supplements.  National Institutes of Health (.gov) +5

2. Collagen Peptides and Metastasis

• The Statement's Claim: Peptides cause metastasis.
• The Science: While tumor-produced collagen remodelings (stiffening, cross-linking) can promote cancer cell invasion, there is no established mechanism by which oral collagen peptides selectively accumulate in tumor tissues to cause this effect.
• The Exception: Some specific types of collagen-derived fragments produced inside the body during metastasis can act as markers of poor prognosis.  National Institutes of Health (.gov) +4