From users, and from around the web with the source linked.
A user says their skin absolutely rejected The Ordinary Niacinamide 10% + Zinc 1%, suspects the zinc, and advises patch testing first.
“My skin absolutely rejected that The Ordinary niacinamide formulation, and I suspect the Zinc component, so do a patch test first.”
Their acne marks got noticeably smaller using it twice a week.
“I like Naturium's tranexamic topical acid 5%. My acne spots noticeably got smaller after using it 2x a week”
Has used it for years: a backlit glow no other vitamin C gives them, oxidises less easily and moisturises, but it's potent and not for beginners.
“It makes my skin glow like the setting sun. I have used it for years”
A user saw a big improvement in skin quality pairing The Ordinary Hyaluronic Acid 2% + B5 with the brand's copper peptide serum.
“I noticed a big improvement in my skin quality combining The Ordinary HA/B5 serum with their Multi-Peptides + Copper.”
An esthetician who says Great Barrier Relief changed their skin and strengthened their barrier; starting tretinoin, they never got flaky.
“I highly recommend trying Krave Beauty Great Barrier Relief Serum. It has changed my skin”
Uses the DIVE-IN serum with the toner; some call it just water, but they find it simple and not irritating.
“I use torriden dive in toner + serum, some people complain it’s basically just water but I find it very simple and not irritating”
Many tiny whiteheads after a week on acne-prone skin.
“I am experiencing many tiny whiteheads after a week of using the ordinarys niamicide and zinc..”
A user finds their skin looks bright and radiant every time they use The Ordinary Niacinamide 10% + Zinc 1%, calling it underrated for about $6.
“The Ordinary’s Niacinamide is about $6. Every time I use that serum my skin looks bright & radiant.”
Layers it with a milky toner in winter for extra hydration on oily, dehydrated skin.
“It's probably not hydrating enough on it's own during the winter, I use it along with the Skin1004 Centella Ampoule.”
On their fourth 95 ml bottle: the only barrier serum that works for their very oily, acne-prone skin on adapalene; it doesn't break them out despite its thicker texture.
“it's the only barrier serum that works for my acne prone skin”
Helped their skin texture when used in the morning alongside a retinoid routine.
“I've tried all three and they all helped me with my skin texture”
Did little beyond mild hydration and made no difference to their face, so they use it on their arms.
“I agree that the CosRx doesn’t do much beyond mild hydration. I ended up using it on my arms because it made no difference to my face.”
Finished a bottle and felt it didn't do much beyond hydration.
“I used Cosrx 6 Peptide skin booster and felt like it didn't do much after finishing the bottle.”
Used alone, the Niacinamide 10% + Zinc worked wonders and practically cleared their dark spots.
“I was using The Ordinary Niacinamide 10% + Zinc 1%, and it worked absolute wonders. It practically made all my dark spots disappear.”
Nice for hydration but no noticeable anti-aging results.
“I do like the Cosrx because it is very nice for hydration and I layer it in when I need extra”
Moved it to body care and isn't sure they'll repurchase.
“I’ve elevated the CosRX to body care.”
Currently using it but not loving the results so far.
“I am using the Cosrx one but not loving it.”
Used the COSRX Vitamin C 23% serum every other day and broke out badly within days; it cleared once they stopped.
“I tried the COSRX Pure Vitamin C 23% Serum every other day for a few weeks, but within days, I started to break out BAD.”
A great budget replacement for Estée Lauder ANR.
“discovered the brand Missha has a great dupe called Time Revolution Night Repair. It’s great!”
Loves it for calming redness and evening out skin tone.
“you should try adding the BoJ calming barrier serum, I LOVE it for redness and evening out tone.”
Has done wonders for their dehydrated, flaky skin under adapalene.
“Cosrx 6 Peptide Serum has done wonders for my dehydrated, flaky skin.”
Tried both Glow Serum and Glow Deep and neither helped their skin.
“I've tried both the Glow Serum and Glow Deep Serum, and both of them did not help my skin in any way.”
They find it a really good product, unlike the 4/10 rating in the post.
“I guess it varies from person to person and from skin to skin :) I find it to be a really good product.”
An oily-dehydrated user's holy-grail routine uses the Torriden Dive-In serum as the base hydration step.
“This is my base hydration step.”