PoreWise One finding · Human trial · 2009
Study title
Improvement of photoaged facial skin in middle-aged Japanese females by topical retinol (vitamin A alcohol): a vehicle-controlled, double-blind study
- Kind of evidence
- Human trial 2009 · 57 people · Middle-aged Japanese women with mild photoaging · PMID 20078381
- Measured outcome
- Irritation
- Year
- 2009
- Who was studied
- Middle-aged Japanese women with mild photoaging
- Sample size
- 57
- Measured outcome
- Nightly 0.075% retinol caused enough irritation for 3 of 57 participants to withdraw from the study; at 0.04% over 13 weeks irritation was reported as minimal, with less improvement in fine wrinkling.
- Certainty
- Low
- Who was measured
- Facial use once nightly in middle-aged Japanese women with mild photoaging, at 0.075% for 26 weeks and 0.04% for 13 weeks.
- Study limits
- Withdrawals were counted. Both findings come from the same single-centre study.
Where it comes from
- Improvement of photoaged facial skin in middle-aged Japanese females by topical retinol (vitamin A alcohol): a vehicle-controlled, double-blind study
Published by Journal of Dermatological Treatment (Kikuchi, Suetake, Kumasaka & Tagami) · Last checked 2026-10-29
Ingredients it was measured on
Other findings on the same ingredient or concern
- Skin effectClassification by causes of dark circles and appropriate evaluation method of dark circles
In a randomized, double-blind, placebo-controlled split-face trial, 24 people with mixed-type dark circles used a test product containing 3% vitamin C, 0.1% vitamin A and 0.5% vitamin E for eight weeks. Brightness (L*), melanin index and image-analysis lightness improved significantly on the treated side compared with the placebo side.
Human trial · 2016 · 24 people · adults with mixed-type dark circles · Instrument-measured brightness, melanin index and skin thickness in mixed-type (pigment plus vascular) dark circles over eight weeks. · Three actives were used together. 24 people took part, all with the mixed type of dark circles; a separate 100-person study was used first to choose which measurements to trust. The abstract reports instrument readings.
- Legal limitsCommission Regulation (EU) 2024/996 amending Regulation (EC) No 1223/2009 — vitamin A (retinol, retinyl acetate, retinyl palmitate), Annex III entry 376
Retinol, retinyl acetate and retinyl palmitate are restricted under Annex III entry 376 of the EU Cosmetics Regulation: at most 0.05% retinol equivalent in body lotion and 0.3% in other leave-on and rinse-off products, with a mandatory label warning.
Official legal text · 2024 · Products placed on the EU market. Other jurisdictions set their own limits. · 2024 · This is a legal limit. · 2024
- Skin effectImprovement of naturally aged skin with vitamin A (retinol)
A 0.4% retinol lotion applied to the arm up to three times a week for 24 weeks reduced fine wrinkling significantly more than its vehicle in elderly subjects: score change −1.64 (95% CI −2.06 to −1.22) against −0.08 (−0.17 to 0.01) on a 0–9 severity scale.
Human trial · 2007 · 36 people · Elderly adults, mean age 87 · Elderly adults, arms. · Thirty-six participants in two senior-care facilities, average age 87, an unusual population for cosmetic use. The glycosaminoglycan and procollagen measurements that suggest a mechanism came from subgroups of six and four participants, far too small to stand on their own.
- Skin effectImprovement of photoaged facial skin in middle-aged Japanese females by topical retinol (vitamin A alcohol): a vehicle-controlled, double-blind study
In a split-face comparison, 0.075% retinol cream used once nightly for 26 weeks improved fine wrinkling in 27 of 54 participants (50%) against 13 (24%) on the vehicle side, and deep wrinkling in 15 (28%) against 1 (2%).
Human trial · 2009 · 57 people · Middle-aged Japanese women with mild photoaging · Middle-aged Japanese women with mild photoaging, 0.075% retinol cream once nightly on the face for 26 weeks. · Single centre, 57 enrolled and 54 evaluated, mild photoaging. The 0.04% arm ran for 13 weeks.
- Skin effectProspective, randomized, double-blind assessment of topical bakuchiol and retinol for facial photoageing
In a 12-week randomized, double-blind trial of 44 people, both 0.5% bakuchiol and 0.5% retinol significantly reduced wrinkle surface area and hyperpigmentation; bakuchiol caused less scaling and stinging.
Human trial · 2019 · 44 people · adults with facial photoageing · Adults with facial photoageing using bakuchiol twice daily or retinol once daily for 12 weeks. · Small sample (44).