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Every verdict on Does It Mix is built on the 173 references below: peer-reviewed studies and reviews (linked to PubMed where available), dermatology society guidance, regulator pages and official product labels.

Pages cite the specific references they rely on. If a link is broken or a source does not support what a page says, email [email protected] and we will correct it. See how verdicts are made and our corrections policy.

  1. Abdel Azim S, et al. Sunscreens part 1: Mechanisms and efficacy. J Am Acad Dermatol. 2025;92(4):677-686.
  2. Acne Solutions Clinical Advanced Clearing Gel (salicylic acid), Drug Facts. Clinique Laboratories. DailyMed, U.S. National Library of Medicine.
  3. Ademola J, Frazier C, Kim SJ, Theaux C, Saudez X. Clinical evaluation of 40% urea and 12% ammonium lactate in the treatment of xerosis. Am J Clin Dermatol. 2002;3(3):217-22.
  4. Ahmed A, Alali AM, Abdullah E, Alharbi MN, Alayoubi HM. Herbal Remedies for Hair Loss: A Review of Efficacy and Safety. Skin Appendage Disord. 2025;11(4):360-371.
  5. Al-Niaimi F, Chiam NYZ. Topical vitamin C and the skin: mechanisms of action and clinical applications. J Clin Aesthet Dermatol. 2017;10(7):14-17.
  6. Albzea W, et al. Azelaic acid versus hydroquinone for managing patients with melasma: systematic review and meta-analysis of randomized controlled trials. Cureus. 2023;15(7):e41796.
  7. American Academy of Dermatology. How do I know if I'm using the right sunscreen?
  8. American Academy of Dermatology. How to apply sunscreen.
  9. American Academy of Dermatology. How to shave.
  10. American Academy of Dermatology. How to test skin care products.
  11. American Academy of Dermatology. Microneedling can fade scars, uneven skin tone, and more.
  12. American Academy of Dermatology. New survey reveals public confusion about risks of tanning and sunburns (May 24, 2022).
  13. American Academy of Dermatology. Retinoid or retinol? Tips for when to use these skin care powerhouses (last updated May 25, 2021).
  14. American Academy of Dermatology. Should I apply my skin care products in a certain order?
  15. Ammonium Lactate Lotion, 12%. Prescribing information. Sun Pharmaceutical Industries. DailyMed, U.S. National Library of Medicine.
  16. Arazlo (tazarotene) lotion, 0.045%. Prescribing information. DailyMed, US National Library of Medicine.
  17. Austin E, Nguyen JK, Jagdeo J. Topical treatments for melasma: a systematic review of randomized controlled trials. J Drugs Dermatol. 2019;18(11):S1545961619P1156X.
  18. AZELEX (azelaic acid) cream 20%. Prescribing information. Almirall. DailyMed, U.S. National Library of Medicine.
  19. Barbaud A, et al. Allergic contact dermatitis from essential oil in consumer products: mode of uses and value of patch tests with an essential oil series. Contact Dermatitis. 2023;89(3):190-197.
  20. Bassett IB, Pannowitz DL, Barnetson RS. A comparative study of tea-tree oil versus benzoylperoxide in the treatment of acne. Med J Aust. 1990;153(8):455-458.
  21. Bikash C. Topical Alternatives for Hair Loss: Beyond the Conventional. Int J Trichology. 2025;17(1):13-19.
  22. Bissett DL, et al. Niacinamide: a B vitamin that improves aging facial skin appearance. Dermatol Surg. 2005;31(7 Pt 2):860-865.
  23. Body Acne Wash (benzoyl peroxide) gel, Drug Facts. Shield Skin LLC. DailyMed, U.S. National Library of Medicine.
  24. Boo YC. Arbutin as a skin depigmenting agent with antimelanogenic and antioxidant properties. Antioxidants (Basel). 2021;10(7):1129.
  25. Boonchaya P, et al. Minimum contact time of 1.25%, 2.5%, 5%, and 10% benzoyl peroxide for a bactericidal effect against Cutibacterium acnes. Clin Cosmet Investig Dermatol. 2022;15:403-409.
  26. Bozzo P, Chua-Gocheco A, Einarson A. Safety of skin care products during pregnancy. Can Fam Physician. 2011;57(6):665-667.
  27. Brubacher JR, Hoffman RS. Salicylism from topical salicylates: review of the literature. J Toxicol Clin Toxicol. 1996;34(4):431-6.
  28. Bylka W, et al. Centella asiatica in cosmetology. Postepy Dermatol Alergol. 2013;30(1):46-49.
  29. Cabtreo (clindamycin phosphate, adapalene and benzoyl peroxide) topical gel. Prescribing information. DailyMed, US National Library of Medicine.
  30. Calacattawi R, et al. Tranexamic acid as a therapeutic option for melasma management: meta-analysis and systematic review of randomized controlled trials. J Dermatolog Treat. 2024;35(1):2361106.
  31. CDC Yellow Book: Mosquitoes, Ticks, and Other Arthropods
  32. CDC: Preventing Mosquito Bites
  33. Celleno L. Topical urea in skincare: a review. Dermatol Ther. 2018;31(6):e12690.
  34. Chaudhuri RK, Bojanowski K. Bakuchiol: a retinol-like functional compound revealed by gene expression profiling and clinically proven to have anti-aging effects. Int J Cosmet Sci. 2014;36(3):221-230.
  35. Chien AL, Qi J, Rainer B, Sachs DL, Helfrich YR. Treatment of acne in pregnancy. J Am Board Fam Med. 2016;29(2):254-262.
  36. CLEOCIN T (clindamycin phosphate) topical solution, lotion and gel. Prescribing information. Pfizer. DailyMed, U.S. National Library of Medicine.
  37. Code of Federal Regulations. 21 CFR 333.310, Acne active ingredients.
  38. Coderch L, et al. Ceramides and skin function. Am J Clin Dermatol. 2003;4(2):107-129.
  39. Cook-Bolden FE, Hamilton SF. An open-label study of the efficacy and tolerability of microencapsulated hydroquinone 4% and retinol 0.15% with antioxidants for the treatment of hyperpigmentation. Cutis. 2008;81(4):365-371.
  40. Dahl MV, Dahl AC. 12% lactate lotion for the treatment of xerosis. A double-blind clinical evaluation. Arch Dermatol. 1983;119(1):27-30.
  41. Darr D, Combs S, Dunston S, Manning T, Pinnell S. Topical vitamin C protects porcine skin from ultraviolet radiation-induced damage. Br J Dermatol. 1992;127(3):247-253.
  42. Dayal S, Kalra KD, Sahu P. Comparative study of efficacy and safety of 45% mandelic acid versus 30% salicylic acid peels in mild-to-moderate acne vulgaris. J Cosmet Dermatol. 2020;19(2):393-399.
  43. Dhaliwal S, et al. Prospective, randomized, double-blind assessment of topical bakuchiol and retinol for facial photoageing. Br J Dermatol. 2019;180(2):289-296.
  44. Dhurat R, et al. A randomized evaluator blinded study of effect of microneedling in androgenetic alopecia: a pilot study. Int J Trichology. 2013;5(1):6-11.
  45. Didierjean L, et al. Biological activities of topical retinaldehyde. Dermatology. 1999;199 Suppl 1:19-24.
  46. Differin (adapalene gel 0.1%) Drug Facts and consumer information. Galderma Laboratories, L.P. DailyMed, U.S. National Library of Medicine (updated December 7, 2022).
  47. Ditre CM, Griffin TD, Murphy GF, et al. Effects of alpha-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study. J Am Acad Dermatol. 1996;34(2 Pt 1):187-95.
  48. Draelos ZD, et al. Dermal sensitization, safety, and tolerability of triple-combination clindamycin phosphate 1.2%/benzoyl peroxide 3.1%/adapalene 0.15% gel from three clinical trials. J Dermatolog Treat. 2023;34(1):2220446.
  49. Draelos ZD, Matsubara A, Smiles K. The effect of 2% niacinamide on facial sebum production. J Cosmet Laser Ther. 2006;8(2):96-101.
  50. Duobrii (halobetasol propionate and tazarotene) lotion, 0.01%/0.045%. Prescribing information. DailyMed, US National Library of Medicine.
  51. Eichenfield LF, Stein Gold L, Kircik LH, et al. Triple-combination clindamycin phosphate 1.2%/benzoyl peroxide 3.1%/adapalene 0.15% gel for moderate-to-severe acne in children and adolescents: randomized phase 2 study. Pediatr Dermatol. 2023;40(3):452-459.
  52. Enshaieh S, et al. The efficacy of 5% topical tea tree oil gel in mild to moderate acne vulgaris: a randomized, double-blind placebo-controlled study. Indian J Dermatol Venereol Leprol. 2007;73(1):22-25.
  53. EPA: Using Insect Repellents Safely and Effectively
  54. Espinal-Perez LE, Moncada B, Castanedo-Cazares JP. A double-blind randomized trial of 5% ascorbic acid vs. 4% hydroquinone in melasma. Int J Dermatol. 2004;43(8):604-607.
  55. Fabi SG, et al. The effects of filtrate of the secretion of the Cryptomphalus aspersa on photoaged skin. J Drugs Dermatol. 2013;12(4):453-457.
  56. Fabior (tazarotene) foam, 0.1%. Prescribing information. DailyMed, US National Library of Medicine.
  57. Feng X, Su H, Xie J. The efficacy and safety of microneedling with topical tranexamic acid for melasma treatment: a systematic review and meta-analysis. J Cosmet Dermatol. 2024;23(1):33-43.
  58. Ferry JJ, Forbes KK, VanderLugt JT, Szpunar GJ. Influence of tretinoin on the percutaneous absorption of minoxidil from an aqueous topical solution. Clin Pharmacol Ther. 1990;47(4):439-446.
  59. Fiume M, et al. Squalane and squalene. Int J Toxicol. 2023;42(3 Suppl):107S-109S.
  60. Garg VK, Sinha S, Sarkar R. Glycolic acid peels versus salicylic-mandelic acid peels in active acne vulgaris and post-acne scarring and hyperpigmentation: a comparative study. Dermatol Surg. 2009;35(1):59-65.
  61. Gorouhi F, Maibach HI. Role of topical peptides in preventing or treating aged skin. Int J Cosmet Sci. 2009;31(5):327-345.
  62. Gorski J, et al. Dexpanthenol in wound healing after medical and cosmetic interventions (postprocedure wound healing). Pharmaceuticals (Basel). 2020;13(7).
  63. Grimes PE, et al. The use of polyhydroxy acids (PHAs) in photoaged skin. Cutis. 2004;73(2 Suppl):3-13.
  64. Grimes PE. A microsponge formulation of hydroquinone 4% and retinol 0.15% in the treatment of melasma and postinflammatory hyperpigmentation. Cutis. 2004;74(6):362-368.
  65. Gupta AK, Nicol K. The use of sulfur in dermatology. J Drugs Dermatol. 2004;3(4):427-431.
  66. Gupta AK, Talukder M, Venkataraman M, Bamimore MA. Minoxidil: a comprehensive review. J Dermatolog Treat. 2022;33(4):1896-1906.
  67. Haralović V, et al. Hypochlorous acid: clinical insights and experience in dermatology, surgery, dentistry, ophthalmology, rhinology, and other specialties. Biomedicines. 2025;13(12):2921.
  68. Hjorther AB, Christophersen C, Hausen BM, Menné T. Occupational allergic contact dermatitis from carnosol, a naturally-occurring compound present in rosemary. Contact Dermatitis. 1997;37(3):99-100.
  69. Hu R, et al. Combined treatment with oral finasteride and topical minoxidil in male androgenetic alopecia: a randomized and comparative study in Chinese patients. Dermatol Ther. 2015;28(5):303-308.
  70. Huang ZR, Lin YK, Fang JY. Biological and pharmacological activities of squalene and related compounds: potential uses in cosmetic dermatology. Molecules. 2009;14(1):540-554.
  71. Hunt MJ, Barnetson RS. A comparative study of gluconolactone versus benzoyl peroxide in the treatment of acne. Australas J Dermatol. 1992;33(3):131-134.
  72. Irby CE, et al. A review of adapalene in the treatment of acne vulgaris. J Adolesc Health. 2008;43(5):421-4.
  73. Ishack S, Lipner SR. Exogenous ochronosis associated with hydroquinone: a systematic review. Int J Dermatol. 2022;61(6):675-684.
  74. Jennings MB, Alfieri D, Ward K, Lesczczynski C. Comparison of salicylic acid and urea versus ammonium lactate for the treatment of foot xerosis. A randomized, double-blind, clinical study. J Am Podiatr Med Assoc. 1998;88(7):332-336.
  75. Kafi R, et al. Improvement of naturally aged skin with vitamin A (retinol). Arch Dermatol. 2007;143(5):606-612.
  76. Kaidbey K, et al. Topical glycolic acid enhances photodamage by ultraviolet light. Photodermatol Photoimmunol Photomed. 2003;19(1):21-27.
  77. Keen MA, Hassan I. Vitamin E in dermatology. Indian Dermatol Online J. 2016;7(4):311-315.
  78. Kligman AM, Willis I. A new formula for depigmenting human skin. Arch Dermatol. 1975;111(1):40-48.
  79. Kong R, et al. A comparative study of the effects of retinol and retinoic acid on histological, molecular, and clinical properties of human skin. J Cosmet Dermatol. 2016;15(1):49-57.
  80. Kornhauser A, Coelho SG, Hearing VJ. Applications of hydroxy acids: classification, mechanisms, and photoactivity. Clin Cosmet Investig Dermatol. 2010;3:135-142.
  81. Ledwoń P, et al. Peptides as active ingredients: a challenge for cosmeceutical industry. Chem Biodivers. 2021;18(2):e2000833.
  82. Lim VZ, Yong AA, Tan WPM, et al. Efficacy and safety of a new cosmeceutical regimen based on the combination of snail secretion filtrate and snail egg extract to improve signs of skin aging. J Clin Aesthet Dermatol. 2020;13(3):31-36.
  83. Lin C, Zhu X. Efficacy of photorejuvenation combined with tranexamic acid and hydroquinone cream in the treatment of complex facial pigmentation. Medicine (Baltimore). 2023;102(34):e34556.
  84. Lin FH, et al. Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin. J Invest Dermatol. 2005;125(4):826-832.
  85. Liu H, et al. Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne. Cochrane Database Syst Rev. 2020;5(5):CD011368.
  86. Lodén M, Boström P, Kneczke M. Distribution and keratolytic effect of salicylic acid and urea in human skin. Skin Pharmacol. 1995;8(4):173-178.
  87. Ly S, Kamal K, Manjaly P, Barbieri JS, Mostaghimi A. Treatment of Acne Vulgaris During Pregnancy and Lactation: A Narrative Review. Dermatol Ther (Heidelb). 2023;13(1):115-130.
  88. Madan RK, Levitt J. A review of toxicity from topical salicylic acid preparations. J Am Acad Dermatol. 2014;70(4):788-792.
  89. Malviya A, Shrivastava S, Pancholi S, et al. A Prospective Study Comparing Clinical Efficacy of 30% Mandelic Acid Peel Versus 30% Lactic Acid Peel in Periorbital Melanosis. Indian Dermatol Online J. 2025;16(6):916-920.
  90. Martin B, et al. Chemical stability of adapalene and tretinoin when combined with benzoyl peroxide in presence and in absence of visible light and ultraviolet radiation. Br J Dermatol. 1998;139 Suppl 52:8-11.
  91. Matin T, Goodman MB. Benzoyl Peroxide. StatPearls. Treasure Island (FL): StatPearls Publishing; 2024.
  92. Meckfessel MH, Brandt S. The structure, function, and importance of ceramides in skin and their use as therapeutic agents in skin-care products. J Am Acad Dermatol. 2014;71(1):177-184.
  93. Miller TR, Wagner JD, Baack BR, Eisbach KJ. Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg. 2006;8(4):252-9.
  94. Mills OH Jr, Kligman AM, Pochi P, Comite H. Comparing 2.5%, 5%, and 10% benzoyl peroxide on inflammatory acne vulgaris. Int J Dermatol. 1986;25(10):664-667.
  95. Minoxidil Topical Solution, 5%. Drug facts label. Sun Pharmaceutical Industries. DailyMed, U.S. National Library of Medicine.
  96. Miroddi M, Calapai G, Isola S, Minciullo PL, Gangemi S. Rosmarinus officinalis L. as cause of contact dermatitis. Allergol Immunopathol (Madr). 2014;42(6):616-9.
  97. Miyazaki A, Taki T, Takeichi T, Kono M, Yagi H, Akiyama M. Darier disease successfully treated with a topical agent containing vitamin A (retinyl palmitate), vitamin E, and urea. J Dermatol. 2022;49(8):779-782.
  98. Mukherjee S, et al. Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety. Clin Interv Aging. 2006;1(4):327-348.
  99. Najafi N, Maatouk H, Vardanyan KG, Vartanian KB, Agrawal DK. A Systematic Review of the Mechanisms and Therapeutic Applications of GHK-Cu in Topical Microneedle Delivery: A Case for Expanded Clinical Trials. Arch Intern Med Res. 2026;9(3):269-293.
  100. Nakagawa M, Kawai K, Kawai K. Contact allergy to kojic acid in skin care products. Contact Dermatitis. 1995;32(1):9-13.
  101. Nyirady J, Lucas C, Yusuf M, Mignone P, Wisniewski S. The stability of tretinoin in tretinoin gel microsphere 0.1%. Cutis. 2002;70(5):295-298.
  102. Ogden S, Samuel M, Griffiths CE. A review of tazarotene in the treatment of photodamaged skin. Clin Interv Aging. 2008;3(1):71-76.
  103. Panahi Y, Taghizadeh M, Marzony ET, Sahebkar A. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed. 2015;13(1):15-21.
  104. PanOxyl Acne Creamy Wash (benzoyl peroxide 4%): Drug Facts. DailyMed, U.S. National Library of Medicine.
  105. Papakonstantinou E, Roth M, Karakiulakis G. Hyaluronic acid: a key molecule in skin aging. Dermatoendocrinol. 2012;4(3):253-258.
  106. Pariser D, et al. Tretinoin gel microsphere pump 0.04% plus 5% benzoyl peroxide wash for treatment of acne vulgaris: morning/morning regimen is as effective and safe as morning/evening regimen. J Drugs Dermatol. 2010;9(7):805-813.
  107. Park KS. Pharmacological effects of Centella asiatica on skin diseases: evidence and possible mechanisms. Evid Based Complement Alternat Med. 2021;2021:5462633.
  108. Pavicic T, et al. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. J Drugs Dermatol. 2011;10(9):990-1000.
  109. Pazoki-Toroudi H, et al. Combination of azelaic acid 5% and clindamycin 2% for the treatment of acne vulgaris. Cutan Ocul Toxicol. 2011;30(4):286-291.
  110. Perricone NV. Treatment of pseudofolliculitis barbae with topical glycolic acid: a report of two studies. Cutis. 1993;52(4):232-235.
  111. Pham HT, Exelbert L, Segal-Owens AC, Veves A. A prospective, randomized, controlled double-blind study of a moisturizer for xerosis of the feet in patients with diabetes. Ostomy Wound Manage. 2002;48(5):30-36.
  112. Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018;19(7):1987.
  113. Pickart L, Vasquez-Soltero JM, Margolina A. GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration. Biomed Res Int. 2015;2015:648108.
  114. Pinnell SR, Yang H, Omar M, et al. Topical L-ascorbic acid: percutaneous absorption studies. Dermatol Surg. 2001;27(2):137-142.
  115. Piquero-Casals J, et al. Urea in dermatology: a review of its emollient, moisturizing, keratolytic, skin barrier enhancing and antimicrobial properties. Dermatol Ther (Heidelb). 2021;11(6):1905-1915.
  116. Proksch E, et al. Topical use of dexpanthenol: a 70th anniversary article. J Dermatolog Treat. 2017;28(8):766-773.
  117. PROPECIA (finasteride) tablets. Prescribing information. Organon LLC. DailyMed, U.S. National Library of Medicine.
  118. Pullar JM, Carr AC, Vissers MCM. The roles of vitamin C in skin health. Nutrients. 2017;9(8):866.
  119. Ravikumar B, et al. Efficacy of Alpha and Beta Hydroxy Acid Chemical Peels in Postacne Pigmentation: A Double Blinded, Randomized, Controlled Trial. J Clin Aesthet Dermatol. 2022;15(1):48-52.
  120. RENOVA (tretinoin cream) 0.02% prescribing information and patient insert. Bausch Health US LLC. DailyMed, U.S. National Library of Medicine (updated February 24, 2026).
  121. Reynolds RV, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2024;90(5):1006.e1-1006.e30.
  122. Robinson LR, Fitzgerald NC, Doughty DG, et al. Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin. Int J Cosmet Sci. 2005;27(3):155-160.
  123. Saeedi M, Eslamifar M, Khezri K. Kojic acid applications in cosmetic and pharmaceutical preparations. Biomed Pharmacother. 2019;110:582-593.
  124. Sauer N, et al. The multiple uses of azelaic acid in dermatology: mechanism of action, preparations, and potential therapeutic applications. Postepy Dermatol Alergol. 2023;40(6):716-724.
  125. Saurat JH, et al. Topical retinaldehyde on human skin: biologic effects and tolerance. J Invest Dermatol. 1994;103(6):770-774.
  126. SCCS, Degen GH. Opinion of the Scientific Committee on Consumer Safety (SCCS): Opinion on the safety of the use of alpha-arbutin in cosmetic products. Regul Toxicol Pharmacol. 2016;74:75-6.
  127. SCCS, Degen GH. Opinion of the Scientific Committee on Consumer Safety (SCCS): Opinion on the safety of the use of beta-arbutin in cosmetic products. Regul Toxicol Pharmacol. 2015;73(3):866-7.
  128. Schlessinger J, Menter A, Gold M, et al. Clinical safety and efficacy studies of a novel formulation combining 1.2% clindamycin phosphate and 0.025% tretinoin for the treatment of acne vulgaris. J Drugs Dermatol. 2007;6(6):607-615.
  129. Sepaskhah M, Karimi F, Bagheri Z, Kasraee B. Comparison of the efficacy of cysteamine 5% cream and hydroquinone 4%/ascorbic acid 3% combination cream in the treatment of epidermal melasma. J Cosmet Dermatol. 2022;21(7):2871-2878.
  130. Shin HS, Won CH, Lee SH, et al. Efficacy of 5% minoxidil versus combined 5% minoxidil and 0.01% tretinoin for male pattern hair loss: a randomized, double-blind, comparative clinical trial. Am J Clin Dermatol. 2007;8(5):285-290.
  131. Singh N, Brown AN, Gold MH. Snail extract for skin: a review of uses, projections, and limitations. J Cosmet Dermatol. 2024;23(4):1113-1121.
  132. Singh R, et al. Review of Tretinoin-Benzoyl Peroxide in The Treatment of Acne Vulgaris. J Drugs Dermatol. 2022;21(10):1098-1103.
  133. Smijs TG, Pavel S. Titanium dioxide and zinc oxide nanoparticles in sunscreens: focus on their safety and effectiveness. Nanotechnol Sci Appl. 2011;4:95-112.
  134. Smith WP. Epidermal and dermal effects of topical lactic acid. J Am Acad Dermatol. 1996;35(3 Pt 1):388-391.
  135. Soltani-Arabshahi R, et al. Facial allergic granulomatous reaction and systemic hypersensitivity associated with microneedle therapy for skin rejuvenation. JAMA Dermatol. 2014;150(1):68-72.
  136. Sorg O, et al. Retinoids in cosmeceuticals. Dermatol Ther. 2006;19(5):289-296.
  137. Stein Gold L, et al. Clindamycin phosphate 1.2%/adapalene 0.15%/benzoyl peroxide 3.1% gel for moderate-to-severe acne: efficacy and safety results from two randomized phase 3 trials. J Am Acad Dermatol. 2023;89(5):927-935.
  138. Tanno O, Ota Y, Kitamura N, Katsube T, Inoue S. Nicotinamide increases biosynthesis of ceramides as well as other stratum corneum lipids to improve the epidermal permeability barrier. Br J Dermatol. 2000;143(3):524-531.
  139. Tantanasrigul P, Sripha A, Chongmelaxme B. The Efficacy of Topical Cosmetic Containing Alpha-Arbutin 5% and kojic acid 2% Compared With Triple Combination Cream for the Treatment of Melasma: A Split-Face, Evaluator-Blinded Randomized Pilot Study. J Cosmet Dermatol. 2025;24(1):e16562.
  140. Tater KC, Gwaltney-Brant S, Wismer T. Topical minoxidil exposures and toxicoses in dogs and cats: 211 cases (2001-2019). J Am Anim Hosp Assoc. 2021;57(5):225-231.
  141. Taylor SC, Torok H, Jones T, et al. Efficacy and safety of a new triple-combination agent for the treatment of facial melasma. Cutis. 2003;72(1):67-72.
  142. Tazorac (tazarotene) cream. Prescribing information. DailyMed, US National Library of Medicine.
  143. Tazorac (tazarotene) gel. Prescribing information. DailyMed, US National Library of Medicine.
  144. Temova Rakuša Ž, Škufca P, Kristl A, Roškar R. Retinoid stability and degradation kinetics in commercial cosmetic products. J Cosmet Dermatol. 2021;20(7):2350-2358.
  145. Tempark T, et al. Efficacy of ceramides and niacinamide-containing moisturizer versus hydrophilic cream in combination with topical anti-acne treatment in mild to moderate acne vulgaris: A split face, double-blinded, randomized controlled trial. J Cosmet Dermatol. 2024;23(5):1758-1765.
  146. Tempark T, Shem A, Lueangarun S. Efficacy of ceramides and niacinamide-containing moisturizer versus hydrophilic cream in combination with topical anti-acne treatment in mild to moderate acne vulgaris: a split face, double-blinded, randomized controlled trial. J Cosmet Dermatol. 2024;23(5):1758-1765.
  147. The Ordinary. AHA 30% + BHA 2% Peeling Solution: product page and ingredient list (accessed October 22, 2026).
  148. The Ordinary. Matrixyl 10% + HA: product page, directions and compatibility list (accessed October 23, 2026).
  149. The Ordinary. Multi-Peptide + copper peptides 1% Serum: product page, directions and compatibility list (accessed October 23, 2026).
  150. Thiboutot DM, et al. Adapalene-benzoyl peroxide, a fixed-dose combination for the treatment of acne vulgaris. J Am Acad Dermatol. 2007;57(5):791-799.
  151. Thiele JJ, Hsieh SN, Ekanayake-Mudiyanselage S. Vitamin E: critical review of its current use in cosmetic and clinical dermatology. Dermatol Surg. 2005;31(7 Pt 2):805-813.
  152. Torok HM, et al. Hydroquinone 4%, tretinoin 0.05%, fluocinolone acetonide 0.01%: a safe and efficacious 12-month treatment for melasma. Cutis. 2005;75(1):57-62.
  153. Treesirichod A, Chaithirayanon S, Chaikul T, Chansakulporn S. The randomized trials of 10% urea cream and 0.025% tretinoin cream in the treatment of acanthosis nigricans. J Dermatolog Treat. 2021;32(7):837-842.
  154. Tretinoin cream and gel prescribing information and patient instructions. Mylan Pharmaceuticals Inc. DailyMed, U.S. National Library of Medicine (updated October 9, 2024).
  155. TRI-LUMA (fluocinolone acetonide 0.01%, hydroquinone 4%, tretinoin 0.05%) cream. Prescribing information. Galderma Laboratories. DailyMed, U.S. National Library of Medicine.
  156. TWYNEO (tretinoin 0.1% and benzoyl peroxide 3%) cream. Prescribing information. Galderma Laboratories. DailyMed, U.S. National Library of Medicine.
  157. U.S. Food and Drug Administration. Alpha Hydroxy Acids. Cosmetic ingredients. Content current as of 11/22/2022.
  158. U.S. Food and Drug Administration. Beta Hydroxy Acids. Cosmetic ingredients. Content current as of 02/25/2022.
  159. U.S. Food and Drug Administration. Dermal Fillers (Soft Tissue Fillers). Content current as of 07/06/2023.
  160. U.S. Food and Drug Administration. FDA works to protect consumers from potentially harmful OTC skin lightening products. Drug Safety Communication, April 19, 2022.
  161. U.S. Food and Drug Administration. Microneedling devices: getting to the point on benefits, risks and safety.
  162. U.S. Food and Drug Administration. Skin Facts! What you need to know about skin lightening products: Skin product safety.
  163. U.S. Food and Drug Administration. The risks of tanning.
  164. Urea Cream 40% (urea) cream. Prescribing information. Laser Pharmaceuticals. DailyMed, U.S. National Library of Medicine.
  165. Yasnova N, Sirait SP, Rahmayunita G. The effectiveness and safety of 3% tranexamic acid cream vs. 4% hydroquinone cream for mixed-type melasma in skin of color: a double-blind, split-face, randomized controlled trial. Acta Dermatovenerol Alp Pannonica Adriat. 2024;33(2):83-88.
  166. Zaenglein AL, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2016;74(5):945-973.
  167. Zanchetta C, Scandolera A, Reynaud R. Hyaluronic Acid in Topical Applications: The Various Forms and Biological Effects of a Hero Molecule in the Cosmetics Industry. Biomolecules. 2025;15(12):1656.
  168. Zduńska K, et al. Antioxidant properties of ferulic acid and its possible application. Skin Pharmacol Physiol. 2018;31(6):332-336.
  169. Zeeshan M, et al. Treatment of acanthosis nigricans with sequential salicylic acid-mandelic acid combination peel and maintenance with glycolic acid-urea combination cream: a retrospective pilot study. J Cosmet Dermatol. 2022;21(9):3905-3909.
  170. Zeichner JA. Optimizing topical combination therapy for the treatment of acne vulgaris. J Drugs Dermatol. 2012;11(3):313-317.
  171. Zhou Y, et al. The effectiveness of combination therapies for androgenetic alopecia: a systematic review and meta-analysis. Dermatol Ther. 2020;33(4):e13741.
  172. ZIANA (clindamycin phosphate 1.2% and tretinoin 0.025%) gel. Prescribing information. Bausch Health US. DailyMed, U.S. National Library of Medicine.
  173. Zilles JC, Dos Santos FL, Kulkamp-Guerreiro IC, Contri RV. Biological activities and safety data of kojic acid and its derivatives: a review. Exp Dermatol. 2022;31(10):1500-1521.

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