Supplement × Supplement·a caution·Insufficient evidence
Acidic vitamin C products layered with copper peptide cosmetics may increase irritation.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
What is happening. Acidic vitamin C products layered with copper peptide cosmetics may increase irritation.
Mechanism. Topical formulation compatibility and skin barrier irritation.
Recommendation. Separate topical vitamin C and GHK-Cu if irritation occurs.
Effect on the composite score
If both GHK-Cu (Copper Peptide) and Vitamin C are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.
Every claim on this page is cited. PMIDs link straight to PubMed.
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NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
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