Azelaic Acid Serum (AZ15) — Reddit Reviews
by Cos De BAHA
Updated October 3, 2026
15% azelaic acid serum that handles redness and hyperpigmentation; thick and sticky.
What the community says
Redditors use this as a morning-friendly azelaic acid serum for redness, PIE, and stubborn red spots. It layers best with patience, since people describe it as thick, sticky, and prone to leaving a white cast on some faces.
What this means for you
What people love
- 15% azelaic acid for redness and PIE
- Plays nicer than Finacea for some rosacea skin
- Low-drama, cheap daily azelaic
Watch out for
Product details
Skin type data limited
Where to buy
What the science says
Acne
Strong evidence
Azelaic Acid: 22 studies tested it on its own. See all 31 studies
What the studies found
- Most studies found azelaic acid helped clear acne
- It often cleared acne better than a placebo
- It worked about as well as tretinoin in several studies
- It could work less well than benzoyl peroxide, though some studies found similar results
- The side effects were usually local skin reactions, and some studies found fewer than with tretinoin
Studied at 5–20%this product: 15%
Hyperpigmentation
Strong evidence
Azelaic Acid: 12 studies tested it on its own. See all 15 studies
What the studies found
- Most studies found azelaic acid helped fade dark spots or patches
- In melasma, it often worked better than a placebo
- In melasma, it worked about as well as 4% hydroquinone and sometimes better than 2% hydroquinone
- Some studies also found it helped acne marks and subtle facial dark patches
- One small study found it did not help sun spots
Studied at 15–20%this product: 15%
Research context, not treatment advice. Studies are about the ingredient, not necessarily this exact product.
Real Reddit threads — 16 mentions across 15 threads
Cos De BAHA Azelaic Acid Serum (AZ15) on Reddit, in one place — 15 threads from r/koreanskincare, r/AsianBeauty and 3 more, summarized.
“My most used ones are Anua and Cos De Baha 10% (daily use)”
Positive
“Cos De Baha 15% (if I don’t catch an inflammation early enough wth tirtir 12%)”
Positive
“I’m always looking for azelaic acid deals, so I will be adding this one on my list to buy whenever there’s a good deal.”
Positive
“Cos de Baha AZ15”
Positive
“15% azelaic acid in an extremely elegant serum.”
Positive
“the AZ15 comes in handy when I’m in a rush in the mornings”
Positive
“Cos de BAHA’s Acid Azelaic 15% leaves a white cast on my face”
Cautionary
“I apply this serum by massaging it into my face and then gently patting my cheeks.”
Cautionary
“azelaic acid is just kinda thick and pasty, white cast is pretty normal with it.”
Cautionary
“Cos De BAHA - AZ15 Serum”
Positive
“I just speed-watched a few videos on hyperpigmentation, and decided to throw the kitchen sink of ingredients at it.”
Positive
“I’m using the other products all over.”
Positive
“I recently got my hands on AZ15 from Cos de Baha”
Positive
“I actually prefer Azalea more as a spot treatment.”
Positive
“I was able to purchase Azalea cream over the counter”
Positive
“Cos de Baha is another brand I really like to find individual products or less complicated, affordable products that have never irritated my skin”
Positive
“Azaleic Acid with hyaluronic acid in particular”
Positive
“I think it's worked well for me.”
Positive
