🧪 What Are AHA & BHA?

Alpha Hydroxy Acids (AHAs) are water-soluble acids like glycolic, lactic, and mandelic acid that exfoliate the surface of the skin by dissolving bonds between dead cells.

Beta Hydroxy Acid (BHA), primarily salicylic acid, is oil-soluble and works deeper inside pores, making it a top pick for acne-prone and oily skin.

INCI Names

- Glycolic Acid, Lactic Acid, Mandelic Acid (AHAs)
- Salicylic Acid (BHA)

1. What Are the Sources of AHA & BHA?

*AHAs (Alpha Hydroxy Acids) are naturally derived from fruits, milk, and sugar sources think of them as nature’s resurfacing agents.

- Glycolic Acid → From sugarcane

- Lactic Acid → From sour milk or fermented vegetables

- Mandelic Acid → From bitter almonds
- Malic & Tartaric Acids → From apples and grapes
 

*BHA (Beta Hydroxy Acid) typically salicylic acid is originally derived from willow bark, birch, or wintergreen leaves. It’s closely related to aspirin (acetylsalicylic acid), which explains its anti-inflammatory powers.

So yes, your exfoliants are basically fruit acids and botanical extracts reimagined for high-performance skincare.

2. Why Are AHA & BHA Often Used Together?

Great question! AHA and BHA are often formulated together because they complement each other beautifully 1)AHAs work on the surface great for smoothing and brightening, 2)BHA goes deeper into the pore excellent for oil and acne control

Think of it like a tag team : one cleans up the top layer, the other clears out below. This combo offers multi-level exfoliation and is especially effective for people dealing with both dullness and breakouts.

📌 Tip: Korean and Western skincare brands both love this pairing in exfoliating toners, pads, and serums and for good reason.

🌱 Origins of AHA & BHA in Skincare

AHA use can be traced back to ancient Egypt, where Cleopatra used sour milk (lactic acid) for smoother skin. Modern cosmetic chemistry embraced glycolic acid in the 1970s.

BHA (salicylic acid) has its roots in willow bark, used for centuries in medicinal applications. Its keratolytic properties became a dermatological gold standard in the late 20th century.

🔬Mechanism of Action (How AHA & BHA Work)

AHAs weaken corneocyte cohesion in the stratum corneum → accelerates exfoliation → promotes even tone & texture
 

BHAs penetrate sebaceous follicles → dissolve sebum + debris → reduce clogged pores, blackheads, and acne
 

Both stimulate cell turnover and increase dermal thickness over time (when used consistently)
 

📖 Reference: Van Scott, E. J., & Yu, R. J. (1989). Alpha Hydroxy Acids: Skin rejuvenation mechanisms. Journal of the American Academy of Dermatology.

📊 Clinical Evidence & Optimal Concentrations of AHA & BHA

※ AHA (Alpha Hydroxy Acids) Common Types : Glycolic Acid, Lactic Acid, Mandelic Acid

(Concentration / Effects / Clinical Support)

✅ Clinical Insight : Glycolic acid is the most researched AHA. It has the smallest molecule size → deeper epidermal penetration.

 ❗ Caution: Over 10% can increase irritation risk always pair with barrier support like ceramides or panthenol.

※ BHA (Beta Hydroxy Acid) Main Type: Salicylic Acid

(Concentration / Effects / Clinical Support)

✅ Clinical Insight: BHA is oil-soluble  penetrates into pores, dissolves sebum and keratin plugs.
 

💡 Bonus: BHA also has natural anti-inflammatory and photoprotective properties (helps calm redness and reduce sun damage over time).

🧴 AHA vs. BHA (Product Formats & Typical Use Levels)

(Product Format / AHA (% Range) / BHA (% Range) / Primary Use Cases)

- Toners, Essences / 0.5–2% / 0.5–2% / Daily gentle exfoliation, hydration balance, light brightening)

- Serums / 5–10% / 1–2% / Resurfacing, tone correction (AHA), pore & acne care (BHA)

<Top 5 Skincare Products Infused with AHA/BHA>

1. COSRX AHA/BHA Clarifying Treatment Toner

Content : Glycolic Acid (0.1%), Salicylic Acid (0.1%)
Country : KR
 

2. Some By Mi AHA BHA PHA 30 Days Miracle Toner

Content : AHA: 0.05% (Lactic), BHA: 0.05% (Willow Bark derived)
Country : KR

3. NEOGEN Bio-Peel Gauze Peeling (Wine/Lemon/Green Tea)

Content : Estimated 5–8% AHA blend (Glycolic/Lactic)
Country : KR

4. By Wishtrend Mandelic Acid 5% Skin Prep Water

Content : Mandelic Acid 5%
Country : KR

5. Isntree Clear Skin 8% AHA Essence

Content : 4% Glycolic + 4% Lactic Acid
Country : KR

📚 Clinical Efficacy

Glycolic Acid (8–10%) shown to improve photoaged skin texture in 6–8 weeks
 (Ditre, C. M. et al., 1996. Journal of the American Academy of Dermatology)
 

Salicylic Acid (2%) effectively treats acne, reduces comedones
 (Kligman, A. M., 1986. Dermatologic Clinics)
 

Combination AHA/BHA regimens improve texture, clarity, and reduce pigmentation
 (Brennan, M. T. et al., 2003. Cutis)

🏛️ Historical Note

Once exclusive to dermatology clinics, AHA/BHA technology is now in everything from drugstore toners to luxury peels. Korean brands, in particular, have innovated with low-irritation, multi-acid formulations suitable for sensitive skin.

💾 Pro Tips from a Skincare Expert

1) Start slow: 2–3x/week with lower % to build tolerance
 

2) Avoid layering with strong retinoids or low pH vitamin C too much irritation risk!
 

3) Always apply broad-spectrum SPF when using exfoliants AHAs increase photosensitivity
 

4) Pair with hydrators like panthenol or beta-glucan to buffer dryness

📚 References

1. Van Scott EJ, Yu RJ. (1989). Alpha Hydroxy Acids and skin rejuvenation. JAAD.
 

2. Ditre CM et al. (1996). Glycolic acid for photoaged skin. JAAD.
 

3. Kligman AM. (1986). Salicylic acid in acne therapy. Dermatol Clin.
 

4. Draelos ZD. (2001). Cosmeceuticals with AHAs and BHAs. J Cosmet Dermatol.
 

5. Berson DS, Cohen JL. (2012). Cosmetic benefits of AHAs/BHAs. Cutis.