AHA vs. BHA: The Exfoliant Showdown Your Skin Needs to Know About

Let’s be honest — skincare can feel like learning a new language sometimes. You finally figure out what a serum is, and then someone throws “AHA” and “BHA” into the conversation like you should automatically know the difference. As an esthetician, I hear this question all the time:

“What even are AHAs and BHAs, and do I actually need them?”

Short answer: yes, you probably do.

Long answer: they’re two types of chemical exfoliants that help your skin shed dead cells, unclog pores, and reveal that smooth, glowy complexion everyone’s chasing. But they do it in totally different ways — and knowing which one your skin craves can make all the difference. So let’s break it down in plain English, shall we?

What Are Chemical Exfoliants, Anyway?

Most people are familiar with physical exfoliants. The scrubs, brushes, and gritty products that physically slough away dead skin. But those can sometimes be harsh or cause micro-tears if you’re not careful (looking at you, apricot scrub). Chemical exfoliants do the same job, just smarter. Instead of scrubbing, they dissolve the “glue” that holds dead skin cells to the surface. They work like tiny bubble baths for your skin cells, breaking down the buildup that’s been hanging on too long so your fresh, glowing layer can finally come through with no harsh rubbing needed. That’s where AHAs and BHAs come in. Both are types of acids; don’t worry, not scary acids — your skin actually loves them, that exfoliate differently depending on your skin’s needs.

AHA: The Brightening, Hydrating Over-Achiever

AHA stands for Alpha Hydroxy Acid, and it’s water-soluble, which means it works on the surface of your skin. If your skin ever feels dull, dry, or rough, AHAs are your best friend. They gently loosen up dead skin cells that make your complexion look tired and flat, revealing that dewy glow underneath. Now lets go over the most common AHAs.

Glycolic Acid

Glycolic acid is the smallest AHA molecule, which means it can penetrate the skin the deepest. It’s derived from sugar cane (yep, glucose!), and it’s one of the most popular exfoliating acids in professional skincare. Because of its small molecular size, it works fast and effectively to boost cell turnover, smooth fine lines and texture, brighten dark spots, firm and plump by stimulating collagen. But — and this is important, glycolic acid can be a little too intense for sensitive skin. If your skin stings, gets red, or feels tight, it’s your cue to scale back and try a gentler AHA instead. Think of glycolic as the overachiever of the bunch: powerful, but needs to be handled with care.

Lactic Acid

Lactic acid comes from milk sugars (lactose), and it’s one of the most forgiving exfoliants out there. It’s larger than glycolic, so it doesn’t sink as deeply — but that’s actually a good thing if your skin is dry, sensitive, or just getting started with acids. Lactic acid not only exfoliates but also attracts water to the skin, giving you that soft, bouncy feel afterward. It’s great for dull, dry, or dehydrated skin, uneven tone, and maintaining moisture barrier health. If glycolic is a strong espresso shot, lactic is your oat milk latte — still effective, just smoother and a little more comforting.

Mandelic Acid

Mandelic acid is derived from bitter almonds, and it has a larger molecular size, meaning it penetrates the skin slowly and evenly. That’s why it’s one of the best options for sensitive, reactive, or acne-prone skin — it exfoliates without drama. It’s antibacterial, helps refine pores, and improves both acne and uneven pigmentation, making it a true multitasker. It’s great for sensitive or acne-prone skin, redness and post-acne marks, gentle brightening and refining. If your skin freaks out easily but you still want glow and clarity, mandelic acid is your calm, dependable friend.

So overall benefits of AHAs are that they smooth fine lines and texture, brighten dull skin, fade dark spots and hyperpigmentation, and improve hydration (especially lactic acid). Remember to always use SPF during the day when you’re using AHAs — they make your skin more sun-sensitive. You just revealed fresh skin; you’ve gotta protect it!

BHA: The Pore-Purifying Problem Solver

Now let’s talk about BHAs, the breakout-fighting, pore-purifying side of chemical exfoliation. If AHAs are your surface smoothers, BHAs are your deep cleaners. They don’t just polish the top layer of your skin; they dive down into your pores to dissolve oil, dead cells, and buildup before they turn into blackheads or breakouts. Think of BHAs as your skin’s internal detox — calm, cool, and always in control. That’s why BHAs are a holy grail for anyone dealing with blackheads, breakouts, or extra shine. The most common BHA is salicylic acid and if you’ve ever used an acne spot treatment, you’ve probably met it before.

Salicylic Acid

Salicylic acid is your one-and-only BHA, and it’s derived from willow bark. (Fun fact: willow bark is the same natural source as aspirin. So if you are allergic to aspirin, you're also allergic to salicylic acid.) It’s oil-soluble, meaning it can slide right into your pores and clear out the gunk, dead cells, sebum, and buildup that causes blackheads and breakouts. It’s also anti-inflammatory, so it’s great for calming angry, red pimples while preventing new ones from forming. It’s great for, oily or acne-prone skin, blackheads and clogged pores, redness and inflammation. If your skin tends to throw a fit when you look at it wrong, salicylic acid is your level-headed bestie that brings balance back.

So in short salicylic acid deep cleans clogged pores, reduces acne and blackheads, calms redness and inflammation and balances oil production. BHAs are powerful little multitaskers. But like anything in skincare, more is not better. Start slow — a couple times a week — and give your skin time to adjust. Pair your BHA with a soothing moisturizer to keep your barrier happy.

So… Which One Do You Actually Need?

Here's an easy breakdown:

Dull or tired skin: AHA, Glycolic acid brightens by removing surface buildup and boosting cell turnover for instant glow.

Dry or flaky skin: AHA, Lactic acid, exfoliates and hydrates — perfect for smoothing and softening without irritation.

Uneven tone / dark spots: AHA, Glycolic or Mandelic acid, helps fade hyperpigmentation and even out texture.

Fine lines or rough texture: AHA, Glycolic acid, stimulates collagen and smooths fine lines over time.

Sensitive or reactive skin: AHA (gentle), Lactic or Mandelic acid, larger molecules = slower penetration = less irritation. Gentle but effective.

Oily or congested skin: BHA, Salicylic acid, cuts through oil, cleans pores, and reduces shine.

Blackheads or whiteheads: BHA, Salicylic acid, deep cleans inside pores to prevent buildup and breakouts.

Acne or blemish-prone skin: BHA (sometimes combo with AHA), Salicylic acid + Mandelic acid, clears existing acne while gently resurfacing post-acne marks.

Combination skin: Both, Lactic acid (AHA) + Salicylic acid (BHA) Alternate days to balance oil and dryness — the best of both worlds.

If you’re dealing with both texture and congestion (because life’s not fair like that), using both acids on alternating days can give you balanced results — smooth, clear, happy skin.

How to Use Them Without Wrecking Your Skin

Chemical exfoliants can do wonders, but they also demand respect. Here’s how to stay on their good side:

1. Start slow. 1–3 times a week max until your skin adjusts.

2. Avoid layering acids or retinol unless directed by a professional.

3. Always, always moisturize afterward. Hydration keeps your barrier strong.

4. SPF every single day. (No excuses!)

5. Listen to your skin. If it burns, flakes, or gets red, take a break.

Remember, exfoliation should reveal your glow — not strip it away.

Pro Esti Tip: Don’t Chase the Tingle

If it tingles or burns, that doesn’t mean it’s “working.” It just means your skin barrier is begging for a break. Healthy skin feels calm, not spicy. If you want that “glazed donut” glow, think balance — not aggression.

Final Thoughts: Let Your Glow Work Smarter, Not Harder

AHAs and BHAs are both total game-changers when used correctly. Think of AHAs as your surface polishers and BHAs as your deep-clean specialists. One smooths, one clears, and together, they help your skin look radiant, even, and alive. So next time you’re scanning a label and see those three little letters, you’ll know exactly what you’re working with — and how to make it work for you. If you found this breakdown helpful, tap the heart on Vocal, share it with your skincare-obsessed friend, or drop a comment about your favorite exfoliant!

With love (and SPF),

Makayla South

Licensed Esthetician | Cultivating Confidence