No.5 Vitamin Concentrated Serum — Reddit Reviews
by numbuzin
Updated November 10, 2026
Redditors praise niacinamide for dark spots; studies find acne results uncertain.
What the community says
This multi-active brightening serum layers easily and suits dry or combination skin chasing acne marks and uneven tone. Redditors report fading for some; studies found topical niacinamide’s acne results uncertain. People with reactive, breakout-prone skin report irritation and breakouts.
What this means for you
What people love
- Tranexamic acid plus niacinamide for pigment-focused routines
- Acne marks and hyperpigmentation visibly fade for many Redditors
- Hydrating, slightly oily-emulsion feel on dry skin
Watch out for
- Not a true vitamin C serum; the vitamin C content is viewed as too weak
- Breakouts, including cystic acne and closed comedones, are reported
- Early irritation or redness makes some users quit
Product details
Use caution
Product Traits
Key Ingredients
What TikTok says
From 7 TikTok videos3 sponsored, marked with outlined numbers
Creators say it is more a niacinamide and tranexamic acid serum than a vitamin C one, since vitamin C sits low on the ingredient list 1. Sponsored creators say it suits dark spots and dullness, with one rating it 100 out of 10 234. Unsponsored creators are mixed: a pharmacist rated it 6 out of 10 5, while another reports more even skin after two weeks and says it suits sensitive and oily skin 6. One sponsored creator says it fits dark spots with uneven tone better than stubborn spots 4.
Sponsored means the creator disclosed a brand partnership or the video ran as a paid ad.
Videos open on TikTok in a new tab.
Where to buy
What the science says
Niacinamide has some evidence for fading dark spots, as all four direct studies found it helped and it outperformed a moisturizer without it 1. For acne, niacinamide has some evidence, with most studies finding it helped and often performing about as well as clindamycin 2. Panthenol has some evidence for strengthening the skin barrier, helping skin hold more water and lose less of it 3. Tranexamic acid has some evidence for fading melasma, though its most common side effects were stomach upset and skin irritation 4.
- Niacinamide for hyperpigmentation Some evidence · 17 studies
- Niacinamide for acne Some evidence · 17 studies
- Panthenol for skin barrier Some evidence · 20 studies
- Tranexamic Acid for hyperpigmentation Some evidence · 19 studies
Research context, not treatment advice. Studies are about the ingredient, not necessarily this exact product.
How we grade researchFull ingredient list · 47
numbuzin No.5 Vitamin Concentrated Serum ingredients
Water, Butylene Glycol, Niacinamide, Panthenol, Tranexamic Acid, 1,2-Hexanediol, Neopentyl Glycol Dicaprate, Caprylic/Capric Triglyceride, Sorbitol, Vaccinium Vitis-Idaea Fruit Extract, Behenyl Alcohol, Pentylene Glycol, Glycerin, Chondrus Crispus Extract, Butyrospermum Parkii (Shea) Butter, 3-O-Ethyl Ascorbic Acid, Saccharum Officinarum (Sugarcane) Extract, Carbomer, Alpha-Arbutin, Bisabolol, Tromethamine, Ethylhexylglycerin, Bifida Ferment Lysate, Adenosine, Hydrogenated Lecithin, Allantoin, Sodium Hyaluronate, Xanthan Gum, Glutathione, Disodium EDTA, Melia Azadirachta Flower Extract, Ocimum Sanctum Leaf Extract, Melia Azadirachta Leaf Extract, Ceramide NP, Curcuma Longa (Turmeric) Root Extract, Corallina Officinalis Extract, Beta-Glucan, Dipotassium Glycyrrhizate, Tocopherol, Ascorbic Acid, Ascorbyl Glucoside, Tocopheryl Acetate, Hydroxypropyl Cyclodextrin, Ubiquinone, Thioctic Acid, Tremella Fuciformis (Mushroom) Extract, Potassium Hydroxide
Listed in label order, highest concentration first. Linked ingredients have their own page.
Real Reddit threads — 116 mentions across 26 threads
numbuzin No.5 Vitamin Concentrated Serum on Reddit, in one place — 26 threads from r/koreanskincare, r/AsianBeauty and 2 more, summarized.
“The Numbuzin No5 serum is incredible! Great haul!”
Mentioned
“Love the haul 😍”
Mentioned
“Yes I totally love Skin1004 and their store in Seoul is so pretty.”
Mentioned
“Numbuzin No.5+ Glutathione Vitamin Concentrated Serum”
Mentioned
“Serums/Creams:”
Mentioned
“Here is the list of items. I've arranged them into categories.”
Mentioned
“numbuzin 5+ serum”
Positive
“Holy grails: acwell licorice toner, haru haru black rice toner, numbuzin 5+ serum”
Positive
“numbuzin 5+ serum and the numbuzin nad+ 9 serum”
Positive
“Numbuzin no5 serum”
Positive
“and Numbuzin no 5 vit c serum ofcourse I'm on my 6th bottle right now”
Positive
“Numbuzin No 5 serum”
Positive
“Added later on: Numbuzin no5 brightening serum (replaced axis-y and vit c)”
Positive
“Numbuzin no5 brightening serum (replaced axis-y and vit c)”
Positive
“I did get these result with this routine.”
Positive
“Yes, I use numbuzin No. 5+ Vitamin Concentrated Serum which is a vitamin complex that contains Glutathione, vitamins B12, B5, C, and E and gives me zero irritation (which I've struggled with for Vitamin C).”
Positive
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