Skip to main content
Shop TIRTIR Niacinamide 20% Serum
Serum
TIRTIR

Niacinamide 20% Serum

~$18.75· 30ml / 1.01 fl ozPM only
Dark spotsVisible poresUneven textureRadianceAcne

What it's good for

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

  • NiacinamideStrong evidenceFull dossier ↗

    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

  • Hyaluronic AcidStrong evidenceFull dossier ↗

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

    Good for: Hydrating

  • GlycerinModerate evidenceFull dossier ↗

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

    Good for: Hydrating

  • GlutathioneModerate evidenceFull dossier ↗

    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

  • RetinolStrong evidenceFull dossier ↗

    Speeds up how fast your skin renews itself so old, dull cells shed faster and fresher skin shows through. Builds collagen over time, smoothing fine lines.

    Good for: Anti-aging

  • Sodium PCAAnecdotal evidenceFull dossier ↗

    Replenishes one of the actual humectant molecules your own skin makes. Levels drop in eczema and with age, so topping it up genuinely helps dry, dehydrated, or atopic-prone skin feel less tight.

    Good for: Hydrating, Barrier repair

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.

NiacinamideStrong evidence10 citations

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

2026Mechanism onlyPMID:42278444View source ↗

Passeron T et al., An Investigator-Blinded, Randomized Trial of a Broad-Spectrum Sunscreen Containing Sclareolide and Niacinamide, Dermatology and Therapy (Heidelberg) 2026

2026Positive (efficacy)PMID:41240206View source ↗

Vergilio MM et al., Topical Formulation with Niacinamide Combined with 5 MHz Ultrasound for Improving Skin Ageing, Current Medicinal Chemistry 2025

2025Positive (efficacy)PMID:39171587View 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 ↗
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 ↗
+3 more ingredients
GlutathioneModerate evidence5 citations

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

2026Meta-analysis (positive)PMID:41900080View source ↗

Sarkar R et al., Glutathione as a skin-lightening agent and in melasma: a systematic review, International Journal of Dermatology 2025

2025Meta-analysis (mixed)PMID:39444151View source ↗

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

2021Positive (efficacy)PMID:33871071View source ↗
RetinolStrong evidence11 citations

Speeds up how fast your skin renews itself so old, dull cells shed faster and fresher skin shows through. Builds collagen over time, smoothing fine lines.

SCCS Revision of the Scientific Opinion on Vitamin A (Retinol, Retinyl Acetate, Retinyl Palmitate), SCCS/1639/21, final version adopted 24-25 October 2022

2022Safety assessmentSCCS/1639/21View source ↗

Chien AL et al. Biomarkers of Tretinoin Precursors and Tretinoin Efficacy in Patients With Moderate to Severe Facial Photodamage: A Randomized Clinical Trial. JAMA Dermatology. 2022;158(8):892-900. doi:10.1001/jamadermatol.2022.1891 — RCT comparing topical retinol precursors vs tretinoin for photoaging; both showed equivalent wrinkle reduction at week 24 with retinol formulation causing 6x less erythema than tretinoin.

2022Positive (efficacy)PMID:35675051View source ↗

MFDS Approved Functional Cosmetic Active — Retinol (anti-wrinkle). Korean Ministry of Food and Drug Safety, Cosmetic Functional Active Ingredient List — listed alongside Adenosine, Retinyl Palmitate, and Polyethoxylated Retinamide in the Korean Functional Cosmetics Codex anti-wrinkle category

2020Regulatory approvalMFDS:Retinol-AntiWrinkleView source ↗
Sodium PCAAnecdotal evidence4 citations

Replenishes one of the actual humectant molecules your own skin makes. Levels drop in eczema and with age, so topping it up genuinely helps dry, dehydrated, or atopic-prone skin feel less tight.

Novel design of pyrrolidonecarboxylic acid and sodium dilauramidoglutamide lysine complex for targeted drug delivery to human stratum corneum, International Journal of Pharmaceutics 2025

2025Mechanism onlyPMID:40187708View source ↗

Baldwin H, Del Rosso J, Going Beyond Ceramides in Moisturizers: The Role of Natural Moisturizing Factors, Journal of Drugs in Dermatology 2024 — review establishing PCA (pyrrolidone carboxylic acid) as a core skin natural moisturizing factor alongside amino acids, urea, lactate, and electrolytes; essential to barrier function and xerosis treatment

2024Mechanism onlyPMID:38834224View source ↗

Li L et al., Association Between Skin Acid Mantle, Natural Moisturizing Factors, and Antibacterial Activity Against S. aureus in the Stratum Corneum, Clinical Cosmetic and Investigational Dermatology 2023 — PCA and urocanic acid as NMF components contribute to skin antibacterial defense; 1-unit pH drop = 68.1% S. aureus cell death

2023Mechanism onlyPMID:37378303View 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.

  • Retinol + salicylic acid can over-exfoliate and damage the barrier. Alternate nights.

  • Retinol + glycolic acid is a classic barrier-buster. Use on different nights.

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

  • Retinol + mandelic acid — alternate nights to preserve barrier integrity.

  • Benzoyl peroxide can break down retinol. Use one in the morning and the other at night, or pick a stabilized formula made to combine them.

  • Vitamin C and retinol work best at different pH levels. Use vitamin C in the morning and retinol at night.

Similar comparisons

← Back to shop

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.