[
  {
    "Study": "Maquart et al., 1988",
    "Design": "Laboratory, cell culture",
    "Who took part": "Human skin fibroblasts",
    "How long": "Not applicable",
    "What was tested": "GHK-Cu added to fibroblast cultures",
    "Compared with": "Untreated cultures",
    "What it found": "Stimulated collagen synthesis at very low concentrations: the finding the later skin studies build on",
    "Published as": "FEBS Letters, peer-reviewed",
    "Authors": "Maquart, Pickart and colleagues",
    "Source": "https://pubmed.ncbi.nlm.nih.gov/3169264/"
  },
  {
    "Study": "Abdulghani et al., 1998",
    "Design": "Pilot, skin biopsies",
    "Who took part": "20 healthy adults",
    "How long": "1 month",
    "What was tested": "GHK-Cu cream on thigh skin",
    "Compared with": "Tretinoin, vitamin C and melatonin creams",
    "What it found": "Increased collagen production in 7 of 10 GHK-Cu users, against 4 of 10 for tretinoin and 5 of 10 for vitamin C.",
    "Published as": "Disease Management and Clinical Outcomes, peer-reviewed",
    "Authors": "Abdulghani and colleagues",
    "Source": "https://doi.org/10.1016/S1088-3371(98)00011-4"
  },
  {
    "Study": "Leyden et al., 2002 (facial cream)",
    "Design": "Clinical study",
    "Who took part": "71 women with mild to advanced sun-ageing",
    "How long": "12 weeks, twice daily",
    "What was tested": "GHK-Cu facial cream",
    "Compared with": "Not stated in the abstract",
    "What it found": "Improved skin laxity, clarity and overall appearance; reduced fine lines and wrinkle depth; increased skin density and thickness",
    "Published as": "Conference abstract, American Academy of Dermatology 60th Annual Meeting",
    "Authors": "Leyden and colleagues",
    "Source": "https://pmc.ncbi.nlm.nih.gov/articles/PMC4508379/"
  },
  {
    "Study": "Leyden et al., 2002 (eye cream)",
    "Design": "Controlled clinical study",
    "Who took part": "41 women",
    "How long": "12 weeks",
    "What was tested": "GHK-Cu eye cream around the eyes",
    "Compared with": "Placebo and a vitamin K eye cream",
    "What it found": "Better than both on lines and wrinkles, overall appearance, skin density and thickness",
    "Published as": "Conference abstract, American Academy of Dermatology 60th Annual Meeting",
    "Authors": "Leyden and colleagues",
    "Source": "https://pmc.ncbi.nlm.nih.gov/articles/PMC4508379/"
  },
  {
    "Study": "Finkley et al., 2005",
    "Design": "Clinical study",
    "Who took part": "67 women aged 50 to 59",
    "How long": "12 weeks, twice daily",
    "What was tested": "GHK-Cu facial cream",
    "Compared with": "Not stated",
    "What it found": "Improved laxity, clarity and firmness; reduced fine lines, coarse wrinkles and mottled pigmentation; increased skin density and thickness",
    "Published as": "Book chapter, Cosmeceuticals and Active Cosmetics, 2nd edition",
    "Authors": "Finkley and colleagues",
    "Source": "https://pmc.ncbi.nlm.nih.gov/articles/PMC4508379/"
  },
  {
    "Study": "Badenhorst et al., 2016",
    "Design": "Randomised, double-blind",
    "Who took part": "About 40 women",
    "How long": "8 weeks, twice daily",
    "What was tested": "GHK-Cu serum in a nano-lipid carrier",
    "Compared with": "The carrier alone, and Matrixyl 3000",
    "What it found": "Wrinkle volume 55.8% lower and wrinkle depth 32.8% lower than the carrier alone; wrinkle volume 31.6% lower than Matrixyl 3000",
    "Published as": "Journal of Aging Science, peer-reviewed",
    "Authors": "Badenhorst and colleagues",
    "Source": "https://www.walshmedicalmedia.com/abstract/effects-of-ghkcu-on-mmp-and-timp-expression-collagen-and-elastin-production-and-facial-wrinkle-parameters-15237.html"
  },
  {
    "Study": "Krüger et al., 2003",
    "Design": "Pilot study",
    "Who took part": "Not recorded",
    "How long": "Not recorded",
    "What was tested": "Topical GHK-Cu complex on aged skin",
    "Compared with": "Not recorded",
    "What it found": "Increased epidermal and dermal thickness; improved hydration, smoothness and elasticity; more collagen I",
    "Published as": "Kosmetische Medizin (German); summarised in Pickart and Margolina, 2018",
    "Authors": "Krüger and colleagues",
    "Source": "https://pmc.ncbi.nlm.nih.gov/articles/PMC6073405/"
  },
  {
    "Study": "Yuvan Research, 2023",
    "Design": "Company clinical trial",
    "Who took part": "21 adults",
    "How long": "3 months",
    "What was tested": "The company's GHK-Cu gel",
    "Compared with": "Not stated",
    "What it found": "Skin collagen density, measured by ultrasound, up 28% on average and 51% in the top quarter",
    "Published as": "Company press release",
    "Authors": "Yuvan Research",
    "Source": "https://www.eurekalert.org/news-releases/990464"
  }
]