Why does this serum look bright blue?

The blue color is the signature of intact copper(II)–tripeptide coordination. A colorless serum means the copper has dissociated, reducing activity.

Is 2% too high? I've seen recommendations of 0.05–0.2%.

The 2% figure is the supplier blend concentration, which contains roughly 5% active peptide on a dry-weight basis. The final free-base active in the product is approximately 0.1%, within the evidence-backed range.

serum30ml

Copper Peptide Serum

Name: Copper Peptide Serum
Brand: The INKEY List
Price: 19.99 USD
Availability: InStock

The INKEY List

The INKEY List's Copper Peptide Serum is a focused single-peptide formulation centered on GHK-Cu (listed as Copper Tripeptide-1 at 2% in supplier blend terms, equivalent to roughly 0.1% free-base active). The added sodium hyaluronate provides immediate hydration layering, which helps with the typical peptide-serum 'dry residue' complaint. Compared to The Ordinary's Buffet + Copper Peptides 1%, this is narrower in mechanism but higher in GHK-Cu concentration — better for users specifically targeting the copper-peptide pathway rather than broad wrinkle-depth coverage.

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Peptides in this product

GHK-Cu (Copper Tripeptide-1)

2% (supplier blend)

Collagen synthesis, antioxidant, wound-healing signaling

Targets

Peptides for Anti-Aging Peptides for Skin & Glow

Key ingredients

Copper Tripeptide-1Sodium Hyaluronate

How to use

Apply to clean skin AM and PM before moisturizer. Avoid direct vitamin C in the same routine. Starts to oxidize once open — discard within 6 months.