AHA vs BHA vs PHA: Korean Acid Exfoliants Compared

Chemical exfoliants dissolve dead skin for a smoother, brighter, clearer complexion — but AHA, BHA, and PHA each suit different skin and concerns. AHAs (glycolic, lactic) are water-soluble and work on the surface for tone and texture.

BHAs (salicylic) are oil-soluble and get inside pores, making them the choice for oily and acne-prone skin. PHAs (gluconolactone) are large, gentle molecules for sensitive skin. This guide compares all three with real Korean examples, keeping the list to Korean brands.

None of these products had a public star rating available, so the picks lean on the acid type instead of review scores; whichever you choose, start slow, don't stack them, and wear sunscreen daily.

How we picked

• Chose real Korean examples of each acid — AHA, BHA, and PHA — plus an AHA/BHA combo.
• Included the category-defining glycolic AHA and salicylic BHA, and gentle PHA options.
• Covered budget to mid-range so you can match the acid to your skin and wallet.
• Kept the list to Korean brands.
• None of these products had a public star rating available, so the ranking leans on acid type instead of review scores.

The acids, by type

1. 코스알엑스 AHA 7 화이트헤드 파워 리퀴드 (COSRX AHA 7 Whitehead Power Liquid) — Type: AHA (glycolic). Brand: 코스알엑스 (COSRX). Price: ₩19,720. Water-soluble surface exfoliation for smoother texture and brighter tone. Best for: dullness, rough texture, and resilient skin. Key spec: 7% glycolic AHA, 100ml.

2. 코스알엑스 BHA 블랙헤드 파워 리퀴드 (COSRX BHA Blackhead Power Liquid) — Type: BHA (betaine salicylate). Brand: 코스알엑스 (COSRX). Price: ₩21,500. Oil-soluble, so it gets inside pores to clear blackheads and oil. Best for: oily, acne-prone, blackhead-prone skin. Key spec: BHA liquid, 100ml.

3. 빌리프 프라블럼 솔루션 비건 PHA 클리어링 토너 (Belif Vegan PHA Clearing Toner) — Type: PHA (gluconolactone). Brand: 빌리프 (Belif). Price: ₩17,000. Large, gentle molecules that exfoliate the surface mildly and hydrate. Best for: sensitive skin and exfoliation beginners. Key spec: PHA toner, 150ml.

4. 오오티디 AHA BHA 클래리파잉 세럼 (OOTD AHA BHA Clarifying Serum) — Type: AHA + BHA combo. Brand: 오오티디 (OOTD). Price: ₩15,000. Surface and in-pore exfoliation in one gentler step. Best for: combination/oily skin wanting both. Key spec: AHA/BHA serum, 50ml.

5. 더마팩토리 글루코노락톤 PHA 10% 트리트먼트 (Derma Factory Gluconolactone PHA 10%) — Type: PHA (gluconolactone). Brand: 더마팩토리 (Derma Factory). Price: ₩6,300. A budget gentle PHA. Best for: sensitive skin on a budget. Key spec: 10% gluconolactone PHA, 150ml.

In-depth: how to choose

Match the acid to your skin type and concern. AHA (alpha hydroxy acid) — glycolic and lactic — is water-soluble, so it works on the skin's surface to dissolve dead cells. It's best for tone, texture, dullness, and dryness (lactic acid is the gentler, more hydrating AHA; glycolic is stronger).

The trade-off: AHAs increase sun sensitivity, so daily sunscreen is non-negotiable. BHA (salicylic acid) is oil-soluble, which means it can penetrate the oily inside of a pore — making it the clear winner for oily, acne-prone, and blackhead-prone skin, since it clears the clogs at the source.

It's also anti-inflammatory, which helps calm breakouts. PHA (polyhydroxy acid) — gluconolactone, lactobionic acid — has larger molecules that stay more on the surface, so it exfoliates gently, stings far less, hydrates, and raises sun sensitivity less.

It's the pick for sensitive, reactive, or rosacea-prone skin, and for beginners. The practical rule: dry/dull/textured skin → AHA; oily/acne/blackheads → BHA; sensitive/reactive → PHA; combination skin → an AHA/BHA combo or alternate.

You don't need all three, and you shouldn't stack strong exfoliants — pick one or two for your skin, start two or three times a week, build up slowly, never layer them with retinol the same night, and wear sunscreen every morning.

Over-exfoliation (redness, stinging, a damaged barrier) is the most common mistake; less is more with acids.

Comparison table

How to buy from outside Korea

These are Korean Naver Shopping listings and may not all ship internationally, so search both the Korean name and the English transliteration. 코스알엑스 (COSRX) and 빌리프 (Belif) are widely stocked on YesStyle, StyleKorean, Amazon, and iHerb, while smaller PHA brands are easiest through Korean-direct sellers.

Choose one acid for your skin type, start slow, and always pair with daily sunscreen.

FAQ

Q: Which acid should I use for my skin type?+

Dry, dull, or textured skin → AHA (glycolic/lactic); oily, acne-prone, or blackhead-prone skin → BHA (salicylic); sensitive or reactive skin → PHA (gluconolactone); combination skin → an AHA/BHA combo. Pick by your main concern, and start with the gentlest option if unsure.

Q: Can I use AHA, BHA, and PHA together?+

You don't need to, and stacking strong acids over-exfoliates. Pick one or two for your skin. If you use more than one, alternate them on different days, and never layer a strong acid with retinol the same night. Watch for irritation as a sign to cut back.

Q: Which acid is the gentlest?+

PHA — its larger molecules exfoliate more on the surface, sting less, hydrate, and raise sun sensitivity less than AHA or BHA. It's the best choice for sensitive, reactive skin and for beginners. Lactic acid is the gentler AHA if you want a mild surface acid.

Q: Do I need sunscreen with all three?+

Yes — all chemical exfoliants make skin more sun-sensitive (AHA most, PHA least), and exfoliation reveals fresh skin that needs protection. Daily sunscreen is non-negotiable with any acid, and it protects the smoother, brighter results you're working for.