08 Jan Everything You Need to Know about AHA and BHA Acids

Exfoliation is an essential step in any skincare routine. It reveals a smoother and more radiant complexion by removing dead skin cells. But not all exfoliants are created equal.

Unlike physical exfoliants, which can sometimes be harsh and abrasive, chemical exfoliants like AHAs and BHAs offer a gentler yet highly effective way to rejuvenate and improve your skin.

Chances are you’ve heard about these acids, but what exactly are they, and how do they work?

Read on to uncover everything you need to know about AHA and BHA exfoliants — and discover which one is right for you.

What Are AHAs?

AHA stands for alpha hydroxy acid, a water-soluble acid that comes from natural sources like fruits, milk, and sugar.

There are three common types of AHAs:

1. Glycolic acid: Derived from sugarcane, it’s the most potent AHA, known for its ability to penetrate deeply and reduce fine lines and surface wrinkles.
2. Lactic acid: Milder than glycolic acid and perfect for sensitive skin, lactic acid comes from milk and helps improve hydration while gently exfoliating.
3. Mandelic acid: Derived from almonds, mandelic acid is another gentle AHA that’s ideal for beginners or those with sensitive skin.

AHAs work by breaking down the bonds that hold dead skin cells together on the surface of your skin. This process encourages skin cell turnover, revealing fresh, younger-looking skin underneath. Being water-soluble, they stay on the surface of the skin, making them ideal for addressing superficial concerns.

The biggest benefits of AHA are that it brightens dull skin tones and age spots, smooths uneven or rough texture, and reduces the appearance of fine lines, wrinkles, and hyperpigmentation. It also boosts hydration and moisture retention by drawing water to the skin.

AHAs are perfect for people with dry, sun-damaged, or mature skin. They are also great for anyone looking to improve overall radiance and reduce signs of ageing.

What Are BHAs?

BHA stands for beta hydroxy acid, a type of oil-soluble acid that comes from natural sources like tree bark, as well as being synthetically grown in labs.

The most well-known type of BHA used in skincare is:

Salicylic acid: Derived from willow bark, salicylic acid is highly effective at reducing oil buildup to help treat congestion issues like pimples and blackheads.

Unlike AHAs, BHAs are oil-soluble, allowing them to penetrate deep into the pores to dissolve sebum and debris.

The biggest advantages of BHA are that it unclogs pores and prevents breakouts, reduces blackheads and whiteheads, and controls excess oil production. It’s also known to calm redness and inflammation, making it suitable for sensitive skin and conditions like rosacea.

BHAs are best suited for people with oily, combination, or acne-prone skin. They are also ideal for those dealing with persistent blackheads, enlarged pores, or redness.

What’s the Difference Between AHA and BHA?

While both AHAs and BHAs are effective exfoliants, they serve different purposes based on your skin type and concerns.

Let’s break down their key features to see how they differ!

Can You Use AHA and BHA Together?

Yes, you can use AHA and BHA together, but it’s important to do so carefully.

Combining them allows you to tackle multiple concerns. For example, an AHA can brighten and smooth your skin’s surface while a BHA can work to clear out your pores.

Many products on the market combine the two for convenience (such as an all-in-one AHA and BHA exfoliant​), offering dual benefits in a single application.

There are three key things you should consider when combining your AHA and BHA exfoliant​s:

1. Start slowly: If you’re new to chemical exfoliation, avoid using both acids at the same time, all the time. Begin by alternating days or using them in different routines (e.g., BHA in the morning, AHA at night).
2. Monitor your skin: Look for signs of irritation, like redness or dryness, and adjust usage accordingly.
3. Layer wisely: If using separate products, apply the thinner, water-based AHA first, followed by the oil-based BHA.

When to Use AHA and BHA?

AHA and BHA products should typically be used during the treatment step of your skincare routine. This is after cleansing and toning but before moisturising.

Always allow around 10–15 minutes for maximum penetration before moving on to the next stage.

BHAs are often used in the morning to reduce oil and prepare the skin for the day. AHAs are typically used at night to repair skin damage and renew the skin while you sleep.

However, you can use them at either time of the day, depending on your personal preference, tolerance and routine compatibility.

Tips for Starting AHA and BHA Products

Regardless of whether you’re using one hydroxy acid or both, it’s important to establish a safe yet effective routine and stick to it to get optimal results.

Here are our top five tips and tricks for using AHA and BHA:

1. Patch test: Test the product on a small area of your skin first to ensure it doesn’t cause irritation or an allergic reaction.
2. Start with low concentrations: Begin with products containing lower percentages (e.g., 5% AHA or 1% BHA) and gradually increase as your skin builds up tolerance.
3. Avoid over-exfoliation: Stick to using an acid just 2–3 times a week to prevent over-exfoliating, which can lead to redness, dryness, and a compromised skin barrier. It’s also advisable to stop using other strong actives like retinoids or vitamin C immediately after applying AHAs or BHAs to minimise irritation.
4. Hydrate and moisturise: Follow up with a hydrating serum or moisturiser to restore your skin barrier and lock in moisture.
5. Use sunscreen daily: Both acids can make your skin more sensitive to the sun. Apply a broad-spectrum sunscreen with at least SPF 30 daily to protect against permanent UV damage.

See our range of exfoliating skincare products, including our ‘CLEAN’ AHA and BHA cleanser, in-store at the Zecca Sydney clinic. The clinic is open 5 days a week, from Tuesday through to Saturday.