Skin science article
Numbuzin No.5 Vitamin Concentrated Serum Versus The INKEY List Tranexamic Acid Serum
Numbuzin No.5 Vitamin Concentrated Serum Versus The INKEY List Tranexamic Acid Serum This brightening serum is formulated around Niacinamide and Tranexamic Acid to fade the look of dark spots and brighten dull-looking skin. This brightening serum is formulated
Numbuzin No.5 Vitamin Concentrated Serum Versus The INKEY List Tranexamic Acid Serum
This brightening serum is formulated around Niacinamide and Tranexamic Acid to fade the look of dark spots and brighten dull-looking skin.
This brightening serum is formulated around Ascorbyl Glucoside and Tranexamic Acid to fade the look of dark spots and brighten dull-looking skin.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Vaccinium Vitis-Idaea Fruit Extract
Butylene Glycol
Niacinamide
Panthenol
Tranexamic Acid
Water
1,2-Hexanediol
Neopentyl Glycol Dicaprate
Caprylic/Capric Triglyceride
Sorbitol
Bifida Ferment Lysate
Chondrus Crispus Extract
Butyrospermum Parkii Butter
Saccharum Officinarum Extract
Alpha-Arbutin
Sodium Hyaluronate
Melia Azadirachta Flower Extract
Ocimum Sanctum Leaf Extract
Melia Azadirachta Leaf Extract
Curcuma Longa Root Extract
Corallina Officinalis Extract
Tremella Fuciformis Extract
Pentylene Glycol
Glycerin
3-O-Ethyl Ascorbic Acid
Bisabolol
Tromethamine
Ethylhexylglycerin
Adenosine
Hydrogenated Lecithin
Allantoin
Glutathione
Ceramide NP
Beta-Glucan
Dipotassium Glycyrrhizate
Tocopherol
Ascorbic Acid
Ascorbyl Glucoside
Tocopheryl Acetate
Hydroxypropyl Cyclodextrin
Ubiquinone
Thioctic Acid
Potassium Hydroxide
Behenyl Alcohol
Carbomer
Xanthan Gum
Disodium EDTA
Vaccinium Vitis-Idaea Fruit Extract, Butylene Glycol, Niacinamide, Panthenol, Tranexamic Acid, Water, 1,2-Hexanediol, Neopentyl Glycol Dicaprate, Caprylic/Capric Triglyceride, Sorbitol, Bifida Ferment Lysate, Chondrus Crispus Extract, Butyrospermum Parkii Butter, Saccharum Officinarum Extract, Alpha-Arbutin, Sodium Hyaluronate, Melia Azadirachta Flower Extract, Ocimum Sanctum Leaf Extract, Melia Azadirachta Leaf Extract, Curcuma Longa Root Extract, Corallina Officinalis Extract, Tremella Fuciformis Extract, Pentylene Glycol, Glycerin, 3-O-Ethyl Ascorbic Acid, Bisabolol, Tromethamine, Ethylhexylglycerin, Adenosine, Hydrogenated Lecithin, Allantoin, Glutathione, Ceramide NP, Beta-Glucan, Dipotassium Glycyrrhizate, Tocopherol, Ascorbic Acid, Ascorbyl Glucoside, Tocopheryl Acetate, Hydroxypropyl Cyclodextrin, Ubiquinone, Thioctic Acid, Potassium Hydroxide, Behenyl Alcohol, Carbomer, Xanthan Gum, Disodium EDTA
Euterpe Oleracea Fruit Extract
1-Methylhydantoin-2-Imide
Sodium Acrylates Copolymer
Phenoxyethanol
Sodium Hydroxide
Cetearyl Olivate
Benzyl Alcohol
Sorbitan Olivate
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Lecithin
Squalane
Sodium Gluconate
Polysorbate 60
Dehydroacetic Acid
Lactobacillus Ferment
Sorbitan Isostearate
Water, Butylene Glycol, Glycerin, Ascorbyl Glucoside, Tranexamic Acid, Euterpe Oleracea Fruit Extract, 1-Methylhydantoin-2-Imide, Sodium Acrylates Copolymer, Phenoxyethanol, Carbomer, Sodium Hydroxide, Cetearyl Olivate, Benzyl Alcohol, Sorbitan Olivate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Lecithin, Squalane, Ethylhexylglycerin, Sodium Gluconate, Polysorbate 60, Dehydroacetic Acid, Lactobacillus Ferment, Sorbitan Isostearate
Reviews
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Ascorbyl Glucoside (AA-2G) is one of the most stable vitamin C derivatives out there.
It's made by attaching a glucose molecule to ascorbic acid; this glucose "cap" shields the vitamin C from air, light, heat, and metal ions that normally cause pure ascorbic acid to oxidize.
Once on your skin, the enzyme alpha-glucosidase snips off the glucose and gradually releases active ascorbic acid right where it's needed. Basically, it behaves like a slow-release pro-vitamin C with less of a stinging that high-strength ascorbic acid can cause.
The research supports the classic vitamin C benefits as well. In lab and human studies, AA-2G slowed down the skin's production of melanin (the pigment behind dark spots) and helped shield skin cells against sun damage better than ascorbyl phosphate.
These studies also showed AA-2G released vitamin C over a longer period.
A frequently cited manufacturer trial found that a 2% AA-2G face cream significantly improved wrinkle depth and skin roughness after 45 days.
And in 2009, a clinical trial showed it meaningfully lightened dark patches on the gums compared to a placebo.
There's also collagen-synthesis support (since vitamin C is a required cofactor for that) and an antioxidant effect too.
Typical usage is usually between 0.5-5% and most studies/products land around 2%.
AA-2G performs best when formulated at a mildly acidic pH (~5-7) which is much gentler than the pH that pure vitamin C demands (~2.5-3.5).
Just one thing worth knowing: the in-skin conversation rate is only about 55-60% by weight. So a 5% AA-2G product delivers roughly 2.75-3% of actual active vitamin C. On top of that, skin absorption is relatively low because the ingredient is water-soluble.
Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.
Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.
Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.
It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.
Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.
A 2024 UK study patch-tested 1,302 patients and found true allergy to the parent group of carbomer to be rare with no confirmed relevant reactions.
Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.
Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Topically, glycerin does several things at once:
Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.
Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.
This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.
Just know very high concentrations (>40%) can feel tacky in low humidity.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Tranexamic Acid (TXA) is a synthetic lysine derivative that is becoming one of the most exciting brightening ingredients in skincare.
Originally used in medicine as an anti-hemorrhagic agent, its skin brightening potential was discovered by accident; patients taking it orally started noticing their melasma was fading.
Unlike most brighteners that target tyrosinase (the enzyme that synthesizes melanin), TXA works further upstream. It basically blocks your cells from receiving the signal to produce pigment.
This makes it one of the rare actives that works on three pathways at once:
This makes it effective for treating melasma, post-inflammatory hyperpigmentation (PIH), and sun-induced dark spots.
The most effective cosmetic concentration sits between 2-5% and going higher doesn't boost results.
Side effects are generally mild; occasional irritation, flaking, or dryness have been reported at the start of use. Overall, this ingredient is pretty well tolerated, even by sensitive skin types.
Another perk of this ingredient is that it does not cause photosensitivity, so it's safe to use in the AM and PM.
Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!