{
  "id": "retinol",
  "idVersion": 1,
  "ingredient": "Retinol (over the counter)",
  "route": "topical",
  "grade": "limited",
  "gradeLabel": "Limited",
  "claim": "Studied in relation to fine lines and surface texture, with results that vary a lot between trials.",
  "caveat": "Retinol is not the same molecule as prescription tretinoin and the evidence is not the same either. Trials are small, formulations differ, and an over the counter product is not required to state how much retinol it contains.",
  "published": "2026-09-19",
  "sources": [
    {
      "url": "https://pubmed.ncbi.nlm.nih.gov/34980969/",
      "journal": "J Clin Aesthet Dermatol",
      "year": 2021,
      "n": null,
      "design": "Systematic review of nine randomized trials",
      "duration": null,
      "percentages": [],
      "outcome": "fine facial wrinkles",
      "finding": "Systematic review of nine randomised trials: four found no significant difference between retinol and vehicle. The five that did gave weak evidence for a mild effect on fine wrinkle lines only, with major methodological flaws.",
      "formulation": null
    },
    {
      "url": "https://pubmed.ncbi.nlm.nih.gov/17515510/",
      "journal": "Arch Dermatol",
      "year": 2007,
      "n": 36,
      "design": "Vehicle-controlled trial",
      "duration": "24 weeks",
      "percentages": [
        "0.4%"
      ],
      "outcome": "fine wrinkles, skin matrix synthesis",
      "finding": "Vehicle-controlled trial of 0.4% retinol in ARM skin, 24 weeks, in 36 residents of two senior citizen facilities, mean age 87: fine wrinkle scores improved against vehicle (-1.64 vs -0.08, P<.001), with higher glycosaminoglycan and procollagen I expression.",
      "formulation": "0.4% retinol lotion"
    }
  ],
  "peopleReport": null
}