K-Beauty BHA 101: Salicylic Acid Without the Sting

TL;DR: BHA (salicylic acid) is the K-beauty go-to for blackheads, whiteheads, and clogged pores. Used the wrong way, it leaves your skin red and peeling. K-beauty fixes that by using BHA in gentler formats and pairing it with calming centella. This guide explains what BHA actually does, how to layer it without wrecking your skin, and our two K-beauty BHA picks — a daily heartleaf ampoule and a 2–3-night-a-week 4% salicylic acid serum.

What Is BHA? (More Than Just a Pore Cleaner)

BHA stands for beta hydroxy acid, and salicylic acid is by far the most common one in skincare. The "beta" describes where the hydroxyl group sits on the molecule — and that geometry, plus an aromatic benzene ring, makes salicylic acid oil-soluble (lipophilic). Alpha hydroxy acids like glycolic and lactic stay on the surface because they're water-soluble. BHA dissolves into the sebum lining your pore — which is where the clog actually lives.

The dermatology research credits salicylic acid with four different mechanisms, all running at the same time:

• Comedolytic: dissolves into the sebum inside the pore and breaks apart the keratin plug from the inside out. This is the "cleans pores" claim.
• Keratolytic: on the surface, loosens the protein bonds (desmosomes) between dead skin cells so they shed evenly instead of in patches.
• Anti-inflammatory: salicylic acid is chemically related to aspirin. It inhibits cyclooxygenase and quiets the NF-κB inflammation pathway. This is why BHA calms an angry red pimple, not just an oily one.
• Sebum-regulating: modulates how much oil your pores pump out in the first place.

A 12-week split-face trial of 30 subjects with mild-to-moderate acne found that 2% salicylic acid cut comedone counts by 42% versus vehicle control. The American Academy of Dermatology lists salicylic acid as one of the top OTC acne ingredients.

The pH catch: salicylic acid is only active in its protonated form, which means the formula needs to sit at a pH of about 3 to 4 to actually work. A label that says "contains salicylic acid" but formulates above pH 4 will exfoliate noticeably less. Lab Muffin Beauty Science has the full breakdown. The K-beauty serums and ampoules we recommend below are all in the active range.

Key takeaways

• BHA works four ways at once: clears the pore, exfoliates the surface, calms inflammation, and dials down sebum.
• Active range is pH 3–4 — check the formula, not just the label.
• Used too strongly, BHA dries and irritates — the K-beauty fix is gentler formats and centella as a partner.
• Start with a daily-use heartleaf BHA ampoule. Layer a higher-strength serum on treatment nights only.
• Use BHA at night. Use sunscreen every morning.
• BHA pairs cleanly with centella, retinol, and vitamin C — just layer in the right order.

AHA vs BHA vs PHA: The Acid Family Cheat Sheet

Korean ingredient lists are full of three-letter acids. Here's the short version of what each one does:

• AHA (alpha hydroxy acid — glycolic, lactic, mandelic): water-soluble, exfoliates on the surface of your skin. Good for dullness and uneven tone.
• BHA (beta hydroxy acid — salicylic acid): oil-soluble, exfoliates inside the pore. Good for blackheads and clogged pores.
• PHA (polyhydroxy acid — gluconolactone): the gentlest cousin. Works on the surface but with bigger molecules that don't sink as deep. Good for sensitive skin.
• LHA (lipohydroxy acid): a slower, more targeted BHA variant. Less common but you'll see it in some K-beauty formulas.

If you want a full deep-dive on the less famous K-beauty ingredients, Into The Gloss has a great explainer on LHA, PHA, bakuchiol, arbutin, and galactomyces.

Salicylic Acid vs Benzoyl Peroxide: Which One Do I Need?

Both treat acne, but they go after different problems:

• Salicylic acid clears clogged pores. Best for blackheads, whiteheads, and the small bumps under the skin (closed comedones).
• Benzoyl peroxide kills acne bacteria on contact. Best for inflamed, painful, pus-filled pimples.

K-beauty leans toward salicylic acid because it doesn't bleach fabric, doesn't dry your skin out as much, and pairs cleanly with calming ingredients like centella. Benzoyl peroxide is still the right tool when bacteria are the main driver of your breakouts — especially for back acne or deep cystic pimples.

Why Centella Makes Your BHA Routine Work

Centella is the K-beauty calming hero. It cuts the inflammation that BHA can cause and keeps your skin barrier strong while the BHA does its job. Cleveland Clinic dermatology PA Samantha Stein put it directly:

"It's common to add Centella Asiatica to products with harsher actives because it reduces the risk of side effects."

That's why every K-beauty BHA routine should have centella layered around it. For the full story on what centella is and how to use it, head to our centella for the big moment guide.

Build Your K-Beauty BHA Routine

A real BHA routine isn't one hero product, it's a sequence: cleanse the oil, lay down the BHA, hold the line on most nights with a gentler trio-acid layer, hit hard 2–3 times a week with the 4% serum, seal everything with a barrier cream, and give your skin a weekly enzyme reset, a PHA pore mask, and a calming finish for nights it gets reactive. Seven steps. Eight anchor products across five brands. Mix-and-match so the routine actually works on your skin.

Step 1 — Cleanse: dissolve sebum first

Oil cleanse, BHA edition. The Innisfree Volcanic BHA Pore Cleansing Oil uses Jeju volcanic cluster powder plus low-dose BHA to dissolve the day's sebum, sunscreen, and makeup. Oil cleansing first means your treatment serums later actually penetrate — they're not fighting through a layer of leftover SPF. Massage onto dry skin, emulsify with water, follow with your usual foam cleanser.

Try the Volcanic BHA Cleansing Oil →

Step 2 — Daily gentle BHA: the everyday layer

Daily-driver BHA. The Sungboon Editor Red Heartleaf BHA-Lino Relief Ampoule is the gentler everyday pick. It pairs salicylic acid with heartleaf, a calming K-beauty botanical. Use it on your T-zone or anywhere you tend to clog, even daily for most skin types. This is the BHA layer that runs all year long.

Try the Red Heartleaf BHA-Lino Ampoule →

Step 3 — Treatment serum: pick the rung that fits the night

Think of BHA strength as a ladder. Most nights you want the middle rung. Treatment nights you want the top rung. Both belong in the same routine — you just don't use them on the same evening.

The SOME BY MI AHA-BHA-PHA 30 Days Miracle Serum stacks low-dose AHA, BHA, and PHA together with niacinamide and tea tree extract. The multi-acid blend works gentler than a single-acid serum because no one acid carries the whole load. Use across the whole face most evenings if your skin tolerates it.

Try the SOME BY MI Miracle Serum →

Step 4 — Seal: moisturize without re-clogging

Barrier seal. The SOME BY MI AHA-BHA-PHA 30 Days Miracle Cream is the seal step from the same line as the serum — lightweight, niacinamide-supported, and formulated to keep oily and combo skin moisturized without re-clogging the pores you just cleared. Pat over everything as the last step on BHA nights.

Try the SOME BY MI Miracle Cream →

Step 5 — Weekly enzyme resurface

Once a week, swap the acid for enzyme. The Mediheal Phyto-Enzyme Peeling Pad uses fruit-derived enzymes to lift dead surface cells without the sting of another acid layer. Use it on a "rest" night between BHA evenings — especially if your skin is starting to feel tight or papery from the actives. Sweep the textured side, flip to the smooth side, follow with your cream.

Try the Phyto-Enzyme Peeling Pad →

Step 6 — Calm and reset: the 15-minute timeout

When your skin talks back. The Mediheal Tea Tree Essential Face Mask is what you reach for when your skin feels hot, reactive, or post-treatment sore. Tea tree calms blemish-prone skin and the soaked essence rehydrates everything BHA just stripped. No acids, no actives — just calm. Use one any night your skin is talking back.

Try the Tea Tree Essential Mask →

Step 7 — Weekly PHA pore mask: the BHA off-night treatment

PHA, the gentlest acid cousin. The Sungboon Editor Green Tomato NMN Pore Minimizing Ampoule Mask uses PHA (polyhydroxy acid — the third acid from the AHA/BHA/PHA cheat sheet up top) plus green tomato extract and NMN to refine pore appearance without the sting. PHA's larger molecules work the surface gently, so this is the right mask for a BHA "off" night when your skin wants treatment but not another round of BHA. Use 1–2x a week.

Try the Green Tomato NMN Pore Mask →

Who Uses BHA — the Artists Who've Named It

Salicylic acid isn't a niche K-beauty thing. Some of the artists with the cleanest, most camera-ready skin in pop have named it in interviews.

Sunmi has discussed using Mediheal's A-Zero Shot Skin Control Pink Dressing as her go-to spot treatment in beauty press — the active stack is salicylic acid, calamine, and sulfur. Mediheal sits squarely in K-beauty's BHA + tea tree tradition; the Mediheal Phyto-Enzyme Peeling Pad and Tea Tree Essential Mask in the routine above come from the same brand lineage.

BTS members Jungkook and V are widely associated with a toner from the SOME BY MI AHA-BHA-PHA line that pairs BHA (salicylic acid), zinc PCA, and ceramides (per Vogue Singapore). The SOME BY MI serum and cream anchoring this routine come from that same line.

Maddie Ziegler uses Sunday Riley's U.F.O. Salicylic Acid BHA Face Oil for her acne-prone skin (per Marie Claire). The format is different — an oil instead of an aqueous serum — but it's the same active doing the same work on the same kind of skin.

The on-set skin expert for the Barbie film put the protocol most plainly: "Always use salicylic acid and ice... ice reduces the heat and inflammation, then salicylic acid helps unclog the pores."

One honest aside. KATSEYE's Sophia Laforteza has spoken publicly about using Accutane for her acne and building an intensely moisturizing routine around the dryness it caused (per Marie Claire). Cosmetic BHA is powerful, but it isn't prescription medicine. If you've tried a careful BHA + centella routine for three to four months and your acne is still cystic, scarring, or covering large areas, that's a dermatology conversation, not a skincare-aisle one.

How to Layer BHA Without Wrecking Your Skin

The K-beauty rule is simple: calm first, treat second, seal last.

Morning: foam cleanse → centella toner → light hydrator → SOME BY MI Miracle Cream → sunscreen. (Skip BHA in the morning — it makes your skin more sun-sensitive.)

Most nights: Innisfree Volcanic BHA Cleansing Oil → foam cleanse → Sungboon Heartleaf BHA Ampoule on T-zone and congested areas → SOME BY MI AHA-BHA-PHA Serum across the rest of the face if your skin can take it → SOME BY MI Miracle Cream to seal.

Treatment nights (2–3 times a week): Innisfree Volcanic BHA Cleansing Oil → foam cleanse → a few drops of the CosDeBAHA 4% Salicylic Acid Serum on stubborn blackheads and closed comedones (skip the Miracle Serum on these nights — don't stack two treatment serums) → SOME BY MI Miracle Cream over everything to seal.

Weekly deep clean (alternate two options): on one "rest" night between BHA evenings, swap your usual toner step for the Mediheal Phyto-Enzyme Peeling Pad — enzyme resurfacing is gentler than acid resurfacing. On a second rest night that week, run the Sungboon Green Tomato NMN Pore Mask instead — PHA refines pore appearance without the BHA sting. Don't stack both in the same night.

Calming reset: any night your skin feels hot, reactive, or post-treatment sore, drop the actives and run the Mediheal Tea Tree Essential Mask for 15 minutes. No BHA. Just calm.

Notice the calming layer — centella, tea tree, the Miracle Cream's barrier support — runs the whole show. The BHA is the guest, not the host.

Sources:

• American Academy of Dermatology — Acne: Treatment options
• American Academy of Dermatology — Daily acne skincare routine
• Medical News Today — What is salicylic acid?
• Healthline — Salicylic acid for acne
• Allure — Everything to know about salicylic acid
• Into The Gloss — What is LHA, PHA, bakuchiol, arbutin, galactomyces?
• Cleveland Clinic (2023) — "Centella asiatica: The most popular skin care ingredient you've never heard of"
• Lab Muffin Beauty Science — "Fact-check: Why does pH matter for AHAs and BHAs?"
• Biosciences Biotechnology Research Asia — "Emerging Formulations and Clinical Applications of Topical Salicylic Acid in Acne Management"
• Vogue Singapore — "The exact skincare products BTS, Twice and Blackpink swear by for ultra-clear skin"
• Marie Claire — "Simple-But-Genius Celebrity Skincare Secrets"
• Marie Claire — "KATSEYE's Sophia Laforteza Loves Drugstore Skincare Products"

This post is editorial commentary. Baerry products are cosmetic skincare, not prescription acne treatment. If your acne is cystic, painful, scarring, or covering large areas of your body, please see a dermatologist. References to artists, performers, and on-set experts cite publicly reported interviews; mention does not imply endorsement of Baerry or any specific Baerry product. All trademarks are the property of their respective owners.