Alpha Hydroxy Acids, glycolic acid from sugarcane, lactic acid from milk, mandelic acid from almonds, are chemical exfoliants that change the texture and brightness of skin faster than almost any other ingredient. Korean beauty's contribution to AHA is the "low and slow" philosophy: consistent use at moderate concentrations (5-8%) in leave-on formats, rather than the occasional high-percentage clinical peels that require days of recovery. This approach delivers cumulative results without disrupting your daily life, and it's made AHAs accessible to people who couldn't consider a 30% glycolic peel but can absolutely fit a 7% lactic acid toner into their nightly routine.
What Does AHA (Alpha Hydroxy Acid) Actually Do?
AHAs dissolve the ionic bonds holding dead skin cells to the surface of the stratum corneum, accelerating their shedding. At pH below 4, glycolic acid also penetrates to the dermis and stimulates fibroblast activity, increasing collagen synthesis and improving skin density. Lactic acid has the additional benefit of increasing ceramide synthesis in keratinocytes, improving barrier function as it exfoliates. Mandelic acid's larger molecular size means slower penetration and less irritation, making it better for sensitive skin and skin of color. All AHAs improve the penetration of subsequently applied actives by clearing the cellular surface layer.
Who Should Use AHA (Alpha Hydroxy Acid)?
AHAs are most valuable for dry skin with texture issues and hyperpigmentation, lactic acid in particular both exfoliates and moisturizes. Aging skin benefits from the collagen stimulation at lower-dermal depths that glycolic acid reaches. Hyperpigmentation of any cause responds well to AHA's accelerated cell shedding. Oily skin can use them too, but BHA is often more directly useful for pore congestion. Sensitive skin should start with lactic or mandelic acid at 5% and build slowly.
How to Add AHA (Alpha Hydroxy Acid) to Your Routine
AHAs go at night, they increase photosensitivity, so morning use isn't recommended without very thorough SPF. Apply on clean, dry skin after your toner, then wait 20-30 minutes before layering other actives to let the pH normalize. Follow with hyaluronic acid and a moisturizer to rehydrate. Don't combine AHAs with retinol or BHA in the same session. The following morning, apply SPF, this is non-negotiable when using exfoliating acids.
- When: Evening only, AHAs increase photosensitivity
- Step: After cleansing and toner, on clean skin; wait 20-30 minutes before layering other actives
- How often: 2-3 times per week initially; some work up to nightly with gradual introduction
- Pair with: Hyaluronic acid (after AHA to rehydrate), niacinamide (the following morning), ceramides
- Avoid: Retinol and BHA in the same session; physical scrubs on the same day; always follow with SPF the next morning
Best Korean AHA (Alpha Hydroxy Acid) Products
Abib Jericho rose PHA toner Skin booster 200ml
$37.44, Toner
A well-formulated Korean toner that delivers AHA as a key active ingredient. It's also formulated with bha, adding complementary benefits to the core AHA action. Best for sensitive skin. Consistent use as part of your daily routine is what gets results, this is a product that rewards regularity.
Anua HEARTLEAF LHA MOISTURE PEELING GEL 120ml
$24.96, Peeling Gel
A well-formulated Korean peeling gel that delivers AHA as a key active ingredient. It's also formulated with centella-asiatica, hyaluronic-acid, pdrn, adding complementary benefits to the core AHA action. Best for dry skin and sensitive skin and rosacea and men. Consistent use as part of your daily routine is what gets results, this is a product that rewards regularity.
Anua RICE ENZYME BRIGHTENING CLEANSING POWDER 40g
$37.44, Cleanser
A well-formulated Korean cleanser that delivers AHA as a key active ingredient. It's also formulated with rice-extract, vitamin-c, ceramides, adding complementary benefits to the core AHA action. Best for dry skin and oily skin and sensitive skin and combination skin and rosacea and hyperpigmentation and men. Consistent use as part of your daily routine is what gets results, this is a product that rewards regularity.
Anua Triple Acid Spot Care Microdart Patch 12ea
$22.88, Patch
A well-formulated Korean patch that delivers AHA as a key active ingredient. It's also formulated with centella-asiatica, hyaluronic-acid, bha, adding complementary benefits to the core AHA action. Best for dry skin and sensitive skin and rosacea and men. Consistent use as part of your daily routine is what gets results, this is a product that rewards regularity.
AROMATICA Pure & S Soft Feminine Wash (Refill) 300ml
$43.68, Feminine Wash
A well-formulated Korean feminine wash that delivers AHA as a key active ingredient. It's also formulated with tea-tree, fermented-extracts, adding complementary benefits to the core AHA action. Best for dry skin and sensitive skin and combination skin and rosacea and men. Consistent use as part of your daily routine is what gets results, this is a product that rewards regularity.
AROMATICA Pure & Soft Feminine Mist Clary Sage & Tea Tree 50ml
$21.84, Feminine Wash
A well-formulated Korean feminine wash that delivers AHA as a key active ingredient. It's also formulated with tea-tree, fermented-extracts, adding complementary benefits to the core AHA action. Best for dry skin and oily skin and acne-prone skin and sensitive skin and rosacea and men. Consistent use as part of your daily routine is what gets results, this is a product that rewards regularity.
FAQ
What is the difference between glycolic and lactic acid?
Glycolic acid is the smallest AHA, penetrating deepest and acting fastest, the most potent but also most irritating. Lactic acid is larger, penetrates more gently, and additionally moisturizes. For beginners or sensitive skin, lactic acid is the better starting AHA. Mandelic acid is gentler still.
Can AHAs make hyperpigmentation worse?
If used improperly, yes, sun exposure after AHA use without SPF can worsen hyperpigmentation, as freshly exfoliated skin is more vulnerable to UV. When paired with daily SPF, AHAs are excellent treatments for hyperpigmentation by accelerating the shedding of pigmented cells.
How do I know if AHA concentration is right for me?
For beginners, start with 5% lactic or mandelic acid. Intermediate users can try 8-10% glycolic. Advanced users may use up to 12-15%. Start using 2x per week and monitor for redness or excessive peeling.
Can I use AHA every day?
Some people with non-sensitive skin work up to daily use after 2-3 months of gradual introduction. Signs of over-exfoliation: redness, stinging, sensitivity, a shiny tight feeling. Reduce frequency before reducing concentration if these occur.
