The Vitamin C 23 Serum

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.”

Several months with no visible result, so they gave up on vitamin C.

“started with Cosrx Vitc 23 for several months and switched to Dr Brenner 20% After that I gave up and stopped using”

Used almost daily for 1–2 years; since stopping they notice their skin slowly losing its glow.

“I was using CosRx 23% Vit Cfor about 1-2 years almost daily in the morning”

Says it is so good and leaves skin feeling nice, though it smells like sausage water.

“Oh this one is so good. My skin feels so nice after this! Also yes it smells like sausage water”

The most effective vitamin C serum they've tried, though it smelled horrible.

“Cosrx vitamin c 23 was the most effective vitamin c serum I have tried. But it smelled horrible, like rotten sausage”

Amazing and swears by it; a bit slow but not unreasonably.

“Cosrx 23 is amazing and I swear by it. Its a bit slow but not unreasonably”

Records no change but thinks their PIH is gradually fading; affordable but smells like spam.

“I dont record any changes before and after use, and ive been using cos de baha azelaic acid serum together for a few months. But i think my pih is gradually fading.”

Found the COSRX 23% smell awful and couldn't deal with it.

“Then I tried Geek & Gorgeous 15% and COSRX 23%, and honestly… the smell is awful. I just can’t deal with it.”

A user finds the COSRX Vitamin C 23 Serum a bit drying, leaving their skin overly dry when applied to dry skin as directed.

“I have been using the COSRX Vitamin C 23% serum and it is a bit drying.”

After two months of nightly use, a combination-skinned user saw no major improvement from the syrupy, strongly scented COSRX Vitamin C 23 Serum and felt a slight tingle; it also stains.

“It has a syrupy consistency, a stronger scent, and I didn't see any major improvements after two months of daily (evening only) usage.”

It burned their skin and took a whole month to recover.

“cosrx vit c23 burned my skin.. It took me a whole month to recover”

Used with a Reedle Shot booster it gave the biggest change in tone and hyperpigmentation within 2 weeks.

“when I started using vt reedle shot 100 and cosrx vit c 23 serum together. It works so well that I was actually surprised.”

Beautiful, absorbs extremely quickly and shows results quicker, but small, pricey and oxidises fast.

“I feel like this shows result quicker than Numbuzin no.5,”

Of three vitamin C serums they tried, a user would only repurchase the COSRX Vitamin C 23 Serum.

“The Vitamin C 23 by COSRX would be the only one I'd be repurchasing”

A user saw immediate brightening from the COSRX Vitamin C 23 Serum but finds its smell so bad it kept them awake.

“Even I got immediate result of brightening after first use of this.”

A user says the COSRX Vitamin C 23 Serum is their favourite because it is the only vitamin C that has ever had a visible effect, though it is strong and sometimes stings.

“Yes, it's my favorite vit c because, really, it's the only one that has ever had any visible effect.”