K-BEAUTY FAQ: Everything You Need to Know About Exfoliating Acids.

Let’s keep diving into the world of exfoliation with a deep dive into acid exfoliants. Today, we’re answering the most frequently asked questions about AHA, BHA, and PHA—the three main categories of chemical exfoliants. These acids are a cornerstone of K-beauty: they visibly brighten and smooth your skin while amplifying the effects of your skincare routine—all without compromising on gentleness.

Unlike scrubs, acid exfoliants don’t just slough off dead skin cells from the surface. They also provide added benefits like hydration, soothing properties, and even antibacterial action. We’ll break down which acid is right for your skin type, why they’re ideal even for sensitive skin, and shine the spotlight on three superstars: salicylic acid, mandelic acid, and gluconic acid.

And of course, we’ll help you find the perfect products to reset your skin—only on miloon.eu.

Exfoliation: A Healthy Skin Routine Starts Here.

Exfoliation is a must—not just when the seasons change, but all year round. Together with double cleansing and toner, exfoliation preps the skin for hydration and nourishment, helping your products penetrate more effectively. Even the most expensive routine won’t work if your pores are clogged and your skin isn’t properly prepped to absorb what comes next.

Acids, Acids Everywhere—Let Your Skin Sing!

Mechanical scrubs, acid toners… the world of exfoliation is vast. But thanks to advances in botanical science and skincare technology, there are now more effective, gentle options for every skin type.

Acid exfoliants still have a bad rap—many think they’re harsh or irritating. But that’s far from the truth. On the contrary, chemical exfoliation is essential for healthy, glowing skin, and acids do far more than exfoliate.

READ MORE: Why Spring Is the Best Time to Exfoliate

At Miloon, we believe good skin comes from good information. So let’s clear up those lingering questions you’ve always had—but never dared to ask—about acid exfoliants.

Why Are Exfoliants So Important?

As we’ve explained in previous guides, exfoliants help your skin shed dead cells and reveal the fresh new ones underneath. It’s a key step for achieving radiant, blemish-free skin.

When Should I Use an Exfoliant in My Routine?

Right after double cleansing and before applying serum or essence.

And How Often?

It depends on your skin type and the exfoliant you’re using. Miloon offers several gentle daily-use formulas—like Wishtrend’s Mandelic Acid—that are even suitable for sensitive skin.

Chemical or Mechanical? The Eternal Debate

Mechanical exfoliants use friction (think scrubs with microbeads) to physically remove dead skin cells.

Chemical exfoliants (acids), on the other hand, dissolve the bonds between dead cells, helping your skin renew itself more gently and evenly. For sensitive skin, chemical exfoliants are almost always the better option.

AHA, BHA, and PHA: What’s the Difference?

• AHA (Alpha-Hydroxy Acids): Derived from fruits or milk, these water-soluble acids work on the surface of the skin to smooth, brighten, and even out tone.
• BHA (Beta-Hydroxy Acids): These are oil-soluble, allowing them to penetrate pores and help clear blackheads, acne, and excess sebum.
• PHA (Polyhydroxy Acids): The gentlest of all, PHAs work on the skin’s surface like AHAs but with added hydration and antioxidant benefits. Ideal for sensitive skin.

Can I Use AHA and BHA Together?

Not on your own. Unless you’re using a product formulated to combine them safely, don’t layer AHA and BHA. It could cause irritation. You can, however, alternate them—AHA in the morning, BHA at night (or vice versa).

When Should I Use Acid Exfoliants?

AHA and BHA can make your skin more sensitive to sunlight, so it’s best to use them at night or with a strong sunscreen during the day. PHA, however, is not photosensitizing, so it can be used during the day without risk—but SPF is always a must!

Which Skin Types Benefit from AHA Exfoliants?

AHAs are best for normal to dry skin, thanks to their hydrating and exfoliating effects. They’re great for stimulating collagen production, reducing dark spots, and smoothing fine lines and acne scars. They work best on well-hydrated skin.

AHA Superstar: Mandelic Acid.

Mandelic acid is a fan favorite—gentle, non-irritating, and great for beginners. It has a larger molecular structure, so it doesn’t penetrate too deeply, reducing irritation. It brightens the skin, helps with melasma and discoloration, and works wonders for acne-prone skin. Bonus: it also helps regulate pH.

Which Skin Types Benefit from BHA Exfoliants?

BHAs are perfect for oily, combination, and acne-prone skin. Since they’re oil-soluble, they go deep into the pores to remove excess sebum and bacteria. They also help reduce inflammation, control breakouts, and refine large pores.

BHA Superstar: Salicylic Acid.

Salicylic acid penetrates deeper than any other BHA. Found naturally in willow bark, it clears pores, reduces oil, and fades pigmentation. It can also regulate sebum production over time. Korean skincare often uses a gentler derivative called Betaine Salicylate, which pairs exfoliating power with hydration—ideal for sensitive skin.

4% Betaine Salicylate ≈ 2% pure Salicylic Acid
K-beauty prefers this because Korean regulations limit pure salicylic acid concentrations in cosmetics.

Which Skin Types Benefit from PHA Exfoliants?

Thanks to their larger molecules, PHAs only act on the surface of the skin, making them suitable for all skin types, especially sensitive or reactive skin. They’re also great for dry skin due to their hydrating and humectant properties.

PHAs also help combat glycation—a process that damages collagen and elastin, leading to premature aging. And unlike AHA and BHA, PHA is not photosensitizing—making it a bit more flexible for daytime use. Still, SPF is non-negotiable!

PHA Superstar: Gluconolactone.

Naturally found in skin cells, gluconolactone is a gentle antioxidant with anti-inflammatory properties. It’s perfect for those who want results without irritation.

READ NOW: Reviews of the 30 Days Miracle Toner by Some By Mi

Shop the Story

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Final Thoughts: Exfoliating Acids Are Your Skin’s Best Friends.

There’s nothing scary about acid exfoliants. In fact, they’re found in a wide range of products—cleansers, toners, masks, moisturizers—and their benefits go way beyond exfoliation.

With continued innovation and botanical research, K-beauty continues to deliver powerful yet gentle formulas that adapt to your skin’s needs. And when it comes to choosing the best ones?

You’ll always find the most effective, skin-loving products right here on miloon.eu.