Sunday Riley A+ High-Dose Retinoid Serum for combination skin

How to apply

Questions and answers

What the research says

• Topical 0.4% retinol significantly increased epidermal thickness, dermal vascularity, and extracellular matrix production by stimulating keratinocyte proliferation, endothelial cell proliferation, and fibroblast activation in naturally aged human skin compared to vehicle.

  International Journal of Cosmetic Science, 2017

• Hydroxypinacolone retinoate and retinyl propionate at a 5:9 weight ratio synergistically enhanced antiaging gene expressions in vitro and improved skin wrinkles, smoothness, transepidermal water loss, and elasticity in 42 Chinese urban women over an 8-week period without adverse reactions compared to retinol.

  Journal of Cosmetic Dermatology, 2023

• Topical retinoids improve global assessment scores and reduce lesion counts compared to vehicle in patients with acne vulgaris, with adapalene demonstrating a superior tolerability profile and benzoyl peroxide combination optimizing results.

  American Journal of Clinical Dermatology, 2019

• Topical application of all-trans-retinol induced epidermal thickening and increased retinoid binding protein expression similar to all-trans-retinoic acid in normal human skin, but without causing significant erythema or measurable retinoic acid levels.

  The Journal of Investigative Dermatology, 1995

• Trifarotene cream 0.005% resulted in a significantly greater reduction in total atrophic acne scar count compared with vehicle at Week 24 (55.2% vs 29.9%) in patients with atrophic acne scarring.

  Dermatology and Therapy, 2025

• Topical application of CoQ10 improves mitochondrial function in aging skin in vivo, combating cellular signs of aging caused by an age-dependent shift to a functionally anaerobic energy metabolism.

  BioFactors, 2008

• Encapsulating coenzyme Q10 in lipid nanoparticles for topical use improves skin compatibility, protects against degradation, increases skin penetration, and provides controlled release to counteract aging effects.

  Colloids and Surfaces. B, Biointerfaces, 2023

• Review of topical administration of carotenoids and coenzyme Q10 loaded in lipid nanoparticles highlights their improved bioavailability, chemical stability, skin absorption, and photoprotective effects.

  Antioxidants, 2021

• Honey-based dressings reduced mean healing duration, length of hospital stay, and VAS pain scores compared with povidone iodine-based dressings in 1236 participants.

  Journal of Wound Care, 2021

• Topical honey application improved the mean duration of attacks and pain, occurrence of crusting, and healing time compared to acyclovir cream in 16 adult patients with recurrent labial and genital herpes lesions.

  Medical Science Monitor, 2004

• A topical serum containing hydroxypinacolone retinoate and peptides used twice daily for 16 weeks achieved parity or statistically significantly better improvement in facial aging parameters compared to a single fractional CO2 laser treatment in women with moderate global photodamage.

  Journal of Cosmetic Dermatology, 2025

• Combined probiotic supplementation and topical azelaic acid with hydroxypinacolone retinoate reduced non-inflammatory lesions from 11.5 to 7.3 and decreased microscopic acne features measured by reflectance confocal microscopy and dynamic optical coherence tomography in 20 patients over 12 weeks.

  Journal of Clinical Medicine, 2023

• A new topical gel formulation reduced total acne lesions by 80% and GAGS scores by 78% after 8 weeks in 22 female patients with mild facial acne without impairing skin barrier function or causing side effects.

  Giornale Italiano Di Dermatologia E Venereologia, 2020

• Topical application of 0.1% hyaluronic acid formulations of different molecular weights led to significant improvements in skin hydration and elasticity, with low-molecular-weight formulations also significantly reducing wrinkle depth in seventy-six female subjects compared to a vehicle control.

  Journal of Drugs in Dermatology, 2011

• Topical application of hyaluronic acid in conjunction with free gingival graft significantly reduced donor site postoperative pain until day 7 compared to normal saline, with no significant differences in graft dimensions or patient satisfaction.

  Clinical Oral Investigations, 2022

• Treatment with a hyaluronic acid-containing mouth rinse or topical gel led to significant lesion reduction, pain relief, and normalization of lesion color in adult patients with minor recurrent aphthous stomatitis, with the gel formulation showing an earlier healing onset at 3 days.

  BMC Oral Health, 2019

Why other serums fit combination skin better

• Niacinamide and ferulic acid incorporated in a stable multiple emulsion successfully reduced melanin, sebum, and skin erythema while improving skin elasticity and hydration in human skin compared to a placebo.

  BioMed Research International, 2022

• A panthenol-enriched mask improved skin hydration, regulated sebum, and reduced redness and TEWL across dry sensitive, oily sensitive, and oily acne skin subgroups with excellent tolerance and no adverse reactions.

  Journal of Cosmetic Dermatology, 2024

Ingredients

Water Eau Agua, Propanediol, Dimethyl Isosorbide, Triheptanoin, Dimethicone, Glycerin, Pentylene Glycol, Hexyldecanol, Disiloxane, Cetyl Peg Ppg-10 1 Dimethicone, Diheptyl Succinate, Propylene Carbonate, Hydroxypinacolone Retinoate, Ppg-24-Glycereth-24, Phenyl Trimethicone, Retinol, Ubiquinone, Honey Extract, Sodium Hyaluronate Crosspolymer, Algae Extract, Zingiber Officinale Extract, Opuntia Ficus-Indica Fruit Extract, Bisabolol, Butyrospermum Parkii Butter Shea Butter, Yeast Extract, Lecithin, Sodium Acrylates Copolymer, Hydrogenated Polyisobutene, 1,2-Hexanediol, 4-T-Butylcyclohexanol, Polyglyceryl-10 Stearate, Caprylyl Glycol, Helianthus Annuus Seed Oil Sunflower Seed Oil, Sorbitol, Cetylhydroxyproline Palmitamide, Polysilicone-11, Benzoic Acid, Dehydroacetic Acid, Sodium Phytate, Glyceryl Polyacrylate, Polysorbate, Hydroxyphenyl Propamidobenzoic Acid, Stearic Acid, Brassica Campestris Sterols, Pvp, Capryloyl Glycerin Sebacic Acid Copolymer, Sodium Benzoate, Alcohol, Potassium Phosphate, Decyl Glucoside, Phenoxyethanol, Hexylene Glycol, Potassium Sorbate, Tocopherol

Behind this fit score

Lovi calculates every fit score from the full ingredient list with brand-independent rules our dermatologists and cosmetic chemists build and review, and personalizes every pick with AI trained on the real results of millions of users. Lovi trains its fit score models on a proprietary dataset built from more than 10,000 expert-labeled products and more than 100,000 simulated examples, following an internally consistent methodology presented at Cosmoprof, AMWC, and Skin of Color Update.