If you’ve ever stood over your skincare shelf trying to decide between AHA and BHA, you’re in very good company. COSRX has two exfoliants that practically own the category — the AHA 7 Whitehead Power Liquid and the BHA Blackhead Power Liquid — and both have millions of loyal fans.
But the real question is: which one is right for your skin?
Let’s make this simple.
AHA vs BHA: What’s the Difference?
AHA (Alpha Hydroxy Acid)
- Water-soluble
- Works on the skin’s surface
- Best for dullness, rough texture, and whiteheads
BHA (Beta Hydroxy Acid)
- Oil-soluble
- Travels deeper into pores
- Best for blackheads, clogged pores, and acne-prone skin
Think of it like this:
AHA = smooth the surface
BHA = clear the inside of the pore
COSRX AHA 7 Whitehead Power Liquid
Main ingredient: 7% Glycolic Acid (AHA)
Best for:
- Whiteheads
- Post-acne marks
- Rough, uneven patches
- Dull or lacklustre skin
How it works:
AHA gently dissolves dead skin cells on the surface, helping skin look brighter, smoother, and more even.
How to use it:
- Start 2–3x per week
- Apply after cleansing and toner
- Follow with hydrating steps (snail mucin is perfect)
- SPF is essential
Choose this if: your main concern is texture, glow, or tiny bump-like whiteheads.
COSRX BHA Blackhead Power Liquid
Main ingredient: 4% Betaine Salicylate (a gentler BHA)
Best for:
- Blackheads
- Enlarged or clogged pores
- Oily or acne-prone skin
- Frequent breakouts
How it works:
BHA penetrates into pores, dissolving excess sebum and buildup to prevent congestion.
How to use it:
- Use 2–3x per week
- Apply after cleansing and toner
- Focus on congested zones (nose, chin, T-zone)
- Always use sunscreen
Choose this if: you deal with blackheads, congestion, or breakouts.
Can You Use Them Together?
Yes — but gently.
Here’s how to layer without irritation:
Option 1: Alternate nights
AHA one night, BHA the next.
Option 2: Spot-specific use
BHA on clogged zones (nose/chin), AHA everywhere else.
Option 3: Weekly double-exfoliation (advanced users only)
AHA → wait 20 mins → BHA
Only once per week.
Pro tip: Always pair exfoliants with barrier-supporting products like COSRX Snail Mucin or Hydrium Moisture Power Enriched Cream.
AHA vs BHA: Quick Guide
Choose AHA if:
✔ Your skin looks dull or textured
✔ You have whiteheads
✔ You want a brighter, smoother finish
Choose BHA if:
✔ You get blackheads
✔ You have oily or acne-prone skin
✔ You want clearer, refined pores
Some skin types use both — just not at the same time.
Both of COSRX’s exfoliating liquids are gentle, effective, and beginner-friendly. AHA smooths. BHA clears. And together, when used properly, they can completely upgrade your skin’s clarity and brightness.
Just remember the golden rule:
start slow, listen to your skin, and never skip SPF.
