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Shop Kit: No. 1 Concentrate
Moisturizer
Kit:

No. 1 Concentrate

~$22· 32 Fl Oz (Pack of 1)

What it's good for

Key actives from our research database. Click any to read the full evidence dossier.

  • GlycerinModerate evidenceFull dossier ↗

    A workhorse hydrator that pulls water into your skin. In nearly every good moisturizer for a reason.

    Good for: Hydrating

  • Hyaluronic AcidStrong evidenceFull dossier ↗

    A pure hydrator that holds water in your skin. Makes skin look plumper and smoother almost immediately.

    Good for: Hydrating

  • Lactic AcidStrong evidenceFull dossier ↗

    A gentler exfoliator that also hydrates as it works. Good entry point if you have sensitive skin and want to try acids.

    Good for: Exfoliating, Hydrating

  • Vitamin CStrong evidenceFull dossier ↗

    Brightens dull skin and helps fade dark spots. Also defends against everyday UV and pollution damage when worn under sunscreen.

    Good for: Brightening, Antioxidant

New to this? Patch test on your inner arm for 24 to 48 hours before applying to your face. If you have sensitive skin or rosacea, start 2 to 3 times per week and build up slowly.

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.

GlycerinModerate evidence6 citations

A workhorse hydrator that pulls water into your skin. In nearly every good moisturizer for a reason.

Danby SG et al., Different types of emollient cream exhibit diverse physiological effects on the skin barrier in adults with atopic dermatitis, Clinical and Experimental Dermatology 2022;47(6):1154-1164 — glycerol+urea emollient delivered superior barrier-strengthening and irritant protection

2022Positive (efficacy)PMID:35167133View source ↗

Youssef R et al., Glycerol 85% efficacy on atopic skin and its microbiome: a randomized controlled trial, Journal of Dermatological Treatment 2021;32(7):730-736 — topical glycerol 85% RCT on atopic skin

2021Positive (efficacy)PMID:31869257View source ↗

Evans NJ et al., Human axillary skin condition is improved following incorporation of glycerol into the stratum corneum from an antiperspirant formulation, Archives of Dermatological Research 2017;309(9):739-748 — 4% glycerol penetrated axillary SC, reduced irritation, improved hydration

2017Positive (efficacy)PMID:28889318View source ↗
Hyaluronic AcidStrong evidence7 citations

A pure hydrator that holds water in your skin. Makes skin look plumper and smoother almost immediately.

Karabat MU, Tuncer MC. Effects of hyaluronic acid on skin at the cellular level: a systematic review. Rev Assoc Med Bras. 2025;71(8):e20250208. — Systematic review of 45 studies found low-molecular-weight HA stimulates keratinocyte proliferation and migration while high-molecular-weight HA drives skin hydration, supporting topical HA as an effective skin-hydrating and barrier-supporting ingredient.

2025Meta-analysis (positive)PMID:40990743View source ↗

Bravo B et al., Benefits of topical hyaluronic acid for skin quality and signs of skin aging: From literature review to clinical evidence, Dermatology and Therapy 2022;12(12):2657-2680 — HA-based cosmeceuticals reliably improve hydration and signs of skin aging

2022Meta-analysis (positive)PMID:36200921View source ↗

Lee SG et al., Hyaluronan Oligosaccharides Improve Rosacea-Like Phenotype through Anti-Inflammatory and Epidermal Barrier-Improving Effects, Annals of Dermatology 2020

2020Mechanism onlyPMID:33911737View source ↗
Lactic AcidStrong evidence5 citations

A gentler exfoliator that also hydrates as it works. Good entry point if you have sensitive skin and want to try acids.

Fanning N et al., Treatment of mild-to-moderate facial cutaneous aging using a combination peel containing 6% trichloroacetic acid and 12% lactic acid, Journal of Cosmetic Dermatology 2023;22(11):3033-3041 — three monthly peels significantly improved clarity, pigmentation, fine lines, roughness in 32 subjects

2023Positive (efficacy)PMID:37227430View source ↗

Tang SC, Yang JH, Dual effects of alpha-hydroxy acids on the skin, Molecules 2018;23(4):863 — effect concentration-dependent

2018Positive (efficacy)PMID:29642579View source ↗

Babilas P et al., Cosmetic and dermatologic use of alpha hydroxy acids, JDDG: Journal der Deutschen Dermatologischen Gesellschaft 2012 — supports AHAs including lactic acid for photoaging, pigmentation, and barrier effects

2012Meta-analysis (positive)PMID:22916351View source ↗
+1 more ingredient
Vitamin CStrong evidence15 citations

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.

2025Meta-analysis (positive)PMID:41152208View source ↗

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

2017Mechanism onlyPMID:28805671View source ↗

Lee JH et al., Effects of VitabridC12 on Skin Inflammation, Annals of Dermatology 2017

2017Mechanism onlyPMID:28966510View source ↗

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.

  • Tretinoin + lactic acid — stack of two active resurfacers, very irritating.

  • Retinolmedium

    Retinol + lactic acid is gentler than glycolic but still alternate nights to be safe.

  • Benzoyl peroxide breaks down vitamin C, making both less effective. Use one in the morning and the other at night.

Similar comparisons

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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.