The compound has not progressed through a drug-approval pathway in any major jurisdiction
Oxidative stress is a well-documented trigger for mast cell degranulation

Common side effects (minimal) Most people: No side effects GHK-Cu extremely well-tolerated Natural peptide (found in body) Minimal adverse effects Possible minor effects: Injection site stinging (common, harmless) Minor bruising at injection sites Slight blue tint to injection site (copper, temporary) Mild headache (rare) Managing side effects: Stinging: Inject slowly, warm peptide to room temp Bruising: Rotate sites, proper technique Blue tint: Normal, fades within days Headache: Hydrate well, reduce dose Contraindications and cautions Avoid if: Pregnancy or breastfeeding (no data) Active cancer (theoretical copper concerns) Wilson's disease (copper metabolism disorder) Hemochromatosis (iron overload, copper caution) Use caution with: Copper supplements (avoid taking both) High copper foods (monitor intake) Liver disease (copper metabolism) Generally safe for: All ages (adults) Men and women Long-term use Most health conditions Copper toxicity concerns Is copper in GHK-Cu dangerous

Analysis of mental and physical disorders associated with COVID-19 in online health forums: a natural language processing study
The stratum corneum has a passive transepidermal absorption ceiling that sits at roughly 500 daltons, which means anything smaller than that has a chance of getting through intact skin and anything larger does not 4
When taking Glutathione, avoid too much sun, as it can lessen its effects