No.5 Vitamin Concentrated Serum
What it's good for
Key actives from our research database. Click any to read the full evidence dossier.
Fades stubborn dark patches like melasma and deep marks left behind by acne or hormonal shifts. The one to reach for when other brighteners haven't worked.
Good for: Brightening
A multitasker that calms redness, evens out skin tone, and helps oily skin balance out. One of the safest do-a-little-of-everything ingredients.
Good for: Brightening, Barrier repair, Anti-inflammatory
A "master antioxidant" your body already makes. In skincare it gently lightens overall tone and helps fade pigmentation when used consistently over months.
Good for: Brightening, Antioxidant
Brightens dull skin and helps fade dark spots. Also defends against everyday UV and pollution damage when worn under sunscreen.
Good for: Brightening, Antioxidant
Pro-vitamin B5. Deeply hydrates and helps repair the skin barrier, calming dry or compromised skin.
Good for: Hydrating, Barrier repair
Refills the natural barrier between your skin cells. Locks moisture in, keeps irritants out, calms dry or damaged skin.
Good for: Barrier repair
Evidence behind the ingredients
Real citations from our research database, one per tracked active in this product. Click any ingredient name to read its full evidence dossier.
Fades stubborn dark patches like melasma and deep marks left behind by acne or hormonal shifts. The one to reach for when other brighteners haven't worked.
Liang Y et al., Comparative efficacy and safety of tranexamic acid for melasma by different administration methods: A systematic review and network meta-analysis, Journal of Cosmetic Dermatology 2024 — oral TXA + topical agents most effective delivery route
Tranexamic Acid Ameliorates Skin Hyperpigmentation by Downregulating Endothelin-1 Expression in Dermal Microvascular Endothelial Cells, Annals of Dermatology 2024;36(3):151-162 — mechanism study showing oral TXA suppresses endothelin-1 in vascular endothelial cells
Calacattawi R, Alshahrani M, Aleid M et al., Tranexamic acid as a therapeutic option for melasma management: a meta-analysis and systematic review of randomized controlled trials, Journal of Dermatological Treatment 2024;35(1):2361106 — pooled RCT evidence that tranexamic acid significantly reduces melasma severity via plasmin-inhibition of UV-triggered melanogenesis
A multitasker that calms redness, evens out skin tone, and helps oily skin balance out. One of the safest do-a-little-of-everything ingredients.
Moro F et al., Skin Cancer Prevention and Antiaging: Role of Nicotinamide, International Journal of Molecular Sciences 2026
Passeron T et al., An Investigator-Blinded, Randomized Trial of a Broad-Spectrum Sunscreen Containing Sclareolide and Niacinamide, Dermatology and Therapy (Heidelberg) 2026
Vergilio MM et al., Topical Formulation with Niacinamide Combined with 5 MHz Ultrasound for Improving Skin Ageing, Current Medicinal Chemistry 2025
A "master antioxidant" your body already makes. In skincare it gently lightens overall tone and helps fade pigmentation when used consistently over months.
Stanescu C et al., Glutathione in Skin Aging and Tissue Regeneration: A Systematic Review of Molecular Mechanisms, Redox Modulation, and Biomedical Implications, Molecules 2026
Sarkar R et al., Glutathione as a skin-lightening agent and in melasma: a systematic review, International Journal of Dermatology 2025
Wahab S et al., Combination of topical and oral glutathione as a skin-whitening agent: a double-blind randomized controlled clinical trial, International Journal of Dermatology 2021;60(8):1013-1018 — 8-week RCT showed combination significantly lowered melanin and raised lightness vs placebo
+−3 more ingredients
Brightens dull skin and helps fade dark spots. Also defends against everyday UV and pollution damage when worn under sunscreen.
Krutmann J et al. PINGing Sunshine: A Review of the Evidence for Adding Non-Filtering Photoprotective Ingredients to Sunscreens. Photodermatol Photoimmunol Photomed. 2025;41(6). — Review of Photoprotective INGredients (PINGs); L-ascorbic acid (vitamin C) identified as a top-ranked PING demonstrating efficacy across multiple photodamage endpoints.
Pullar JM et al., The roles of vitamin C in skin health, Nutrients 2017;9(8):866 — concluded topical efficacy "poorly understood"; supports dietary vitamin C
Lee JH et al., Effects of VitabridC12 on Skin Inflammation, Annals of Dermatology 2017
Pro-vitamin B5. Deeply hydrates and helps repair the skin barrier, calming dry or compromised skin.
Gao Y et al., Evaluation of the Efficacy and Safety of a Panthenol-Enriched Mask for Skin Barrier Recovery After Facial Laser Treatment, Journal of Cosmetic Dermatology 2025;24(7):e70223 — double-blind RCT (n=60): panthenol mask decreased erythema, enhanced hydration, repaired barrier vs saline
Cho YS et al., Use of Dexpanthenol for Atopic Dermatitis-Benefits and Recommendations Based on Current Evidence, Journal of Clinical Medicine 2022;11(14):3943 — Korean-authored review; dexpanthenol improves barrier and reduces severity in mild-to-moderate AD
Heise R et al., Accelerated wound healing with a dexpanthenol-containing ointment after fractional ablative CO2 laser resurfacing of photo-damaged skin in a randomized prospective clinical trial, Cutaneous and Ocular Toxicology 2019;38(3):274-278 — RCT: dexpanthenol significantly faster wound closure vs petroleum jelly post-laser
Refills the natural barrier between your skin cells. Locks moisture in, keeps irritants out, calms dry or damaged skin.
Andrew PV et al., Topical supplementation with physiological lipids rebalances the stratum corneum ceramide profile and strengthens skin barrier function in adults predisposed to atopic dermatitis, British Journal of Dermatology 2025;193(4):729-740 — physiological-lipid emulsion raised SC ceramide NP/AP and improved barrier function vs control
Nugroho WT, Sawitri, Astindari, Utomo B, Listiawan MY, Ervianti E, Astari L. The Efficacy of Moisturisers Containing Ceramide Compared with Other Moisturisers in the Management of Atopic Dermatitis: A Systematic Literature Review and Meta-Analysis. Indian J Dermatol. 2023;68(1):53-58. — Meta-analysis of 5 studies found ceramide-containing moisturisers produced significantly greater improvement in SCORAD compared with non-ceramide moisturisers in atopic dermatitis.
Shindo S et al., Effects of a moisturizer containing pseudo-ceramide and a eucalyptus extract on sweating function in adult atopic dermatitis: a double-blind, randomized, controlled left-right comparison clinical trial, Journal of Cosmetic Dermatology 2022;21(10):4503-4509 — pseudo-ceramide + eucalyptus moisturizer restored sweating function and barrier in AD adults
Sources: 10 clinical journals and regulatory databases across the US, EU, Korea, Japan, and China. Every entry points to a specific document. See methodology for the full list and what each outcome label means.
Layering conflicts
Ingredients in this product that can react with common actives. Avoid stacking unless noted.
- Benzoyl Peroxidemedium
Benzoyl peroxide breaks down vitamin C, making both less effective. Use one in the morning and the other at night.
- Retinollow
Vitamin C and retinol work best at different pH levels. Use vitamin C in the morning and retinol at night.
Similar comparisons
Not medical advice. GlowPal is educational. Patch-test new products and talk to a qualified healthcare professional before changing your routine, especially if you're pregnant, nursing, or have a diagnosed skin condition. See our terms.