Chemical exfoliation can be a glow game-changer—but the science-y language around it often makes the process feel more intimidating than it needs to be. At the center of the confusion is the classic skincare fork in the road: AHA vs. BHA. Both are exfoliating acids that work by dissolving the “glue” holding dead skin cells together, but they behave very differently on the skin.
BHA vs AHA — Which Chemical Exfoliant Should You Use?
Demystifying the acids: A complete guide to choosing the right exfoliant for your skin type.
Chemical exfoliation is the secret to a glowing complexion, but the alphabet soup of ingredients can be confusing. When deciding BHA vs AHA which to use, the answer lies in understanding your skin’s specific needs. While both remove dead skin cells to reveal smoother texture, their methods of action differ fundamentally.
The Core Differences
AHAs (Alpha Hydroxy Acids) are water-soluble. They work primarily on the skin’s surface, melting the “glue” that holds dead skin cells together. They are hydrophilic (water-loving), making them excellent for retaining moisture.
BHAs (Beta Hydroxy Acids) are oil-soluble. This unique property allows them to bypass the oil on your skin’s surface and penetrate deep inside the pores. They are lipophilic (oil-loving), making them capable of clearing out sebum blockages.
Figure 1: AHAs exfoliate the surface, while BHAs penetrate the pore lining.
Side-by-Side Comparison (BHA vs AHA)
AHA (Alpha Hydroxy)
- Solubility: Water-soluble
- Best for: Dry, sun-damaged, normal skin
- Target: Surface roughness, fine lines, pigmentation
- Ingredients: Glycolic Acid, Lactic Acid, Mandelic Acid
- Effect: Brightening & Hydrating
BHA (Beta Hydroxy)
- Solubility: Oil-soluble
- Best for: Oily, acne-prone, combination skin
- Target: Blackheads, whiteheads, enlarged pores
- Ingredients: Salicylic Acid, Betaine Salicylate
- Effect: Decongesting & Anti-inflammatory
✨ When to Choose COSRX BHA Blackhead Power Liquid
If you struggle with “strawberry nose,” persistent blackheads, or midday shine, a dedicated BHA is your best friend. The COSRX BHA Blackhead Power Liquid is a cult favorite because it uses Betaine Salicylate (4%), a gentler alternative to harsh salicylic acid that still delivers deep pore cleaning without the sting.
Pro Tip: Apply it to a cotton pad and leave it on your nose for 5 minutes like a mini sheet mask to dissolve stubborn sebum.
Check Price on AmazonRoutine Examples
Click below to see how to incorporate these acids into your regimen.
AM: Gentle Foam Cleanser → Hydrating Toner → SPF 50.
PM: Oil Cleanser → BHA Liquid (3x/week) → Gel Moisturizer.
Focus: Unclogging pores without stripping moisture.
AM: Water Rinse → Vitamin C Serum → SPF 50.
PM: Cream Cleanser → Lactic Acid 5% (1-2x/week) → Ceramide Cream.
Focus: Gently removing flakes while maintaining barrier health.
AM: Cleanser → Niacinamide Serum → SPF.
PM: Cleanser → Skin Cycling (Night 1: AHA, Night 2: Retinol, Night 3&4: Recovery).
Focus: Balanced exfoliation and anti-aging.
Frequently Asked Questions
Can I use AHA and BHA at the same time?
Technically yes, but it increases the risk of irritation. It is safer to use them at different times of the day (e.g., BHA in the morning, AHA at night) or on alternate nights.
Which is better for acne scars?
AHAs are generally better for fading surface pigmentation and dark spots (PIH) left behind by acne. BHAs help prevent the acne that causes the scarring in the first place.
Do I need to wear sunscreen with these?
Absolutely. AHAs make your skin significantly more sensitive to the sun (photosensitivity). BHAs are less photosensitizing, but you should always wear SPF 30+ regardless to protect your results.