Walking into Sephora can feel a little overwhelming. Every product promises brighter, smoother, glowier skin, and suddenly you’re trying to figure out whether you need an AHA, a BHA, or something else entirely. If you’ve ever felt confused by skincare ingredients, you’re definitely not alone.
I’m not a dermatologist or skincare expert—just someone who has tested a lot of skincare products and has spent plenty of time researching the ingredients behind them. That’s what inspired this series: breaking down the skincare ingredients everyone seems to be talking about in a way that’s actually easy to understand.
This is the first installment of The Skincare Breakdown, where we’ll look at what popular skincare ingredients do, who they’re best for, and how to use them. We’re kicking things off with one of the most talked-about categories: Alpha Hydroxy Acids (AHAs) and Beta Hydroxy Acids (BHAs). Think of this as part one of your guide to understanding acids in skincare. is a little cheat sheet. This serves as the first post of a series of skincare posts tackling the skincare ingredients everyone likes to talk about but never seems to explain what they do and why we should use them. For today’s post, we’re tackling acids, AHAs and BHAs. This is just part one of our guide on all things acids.
What Are AHAs/BHAs?
AHAs is short for Alpha Hydroxy Acids, and BHAs are short for Beta-Hydroxy Acids.
Despite the name sounding a little intimidating, many acids are actually some of the most effective ingredients in skincare. Depending on the type, they can exfoliate dead skin cells, boost hydration, brighten the complexion, support the skin barrier, provide antioxidant protection, or even help treat acne.
In this article, we’re focusing on chemical exfoliating acids, which are generally divided into two main categories: Alpha Hydroxy Acids (AHAs) and Beta Hydroxy Acids (BHAs).
AHAs (Alpha Hydroxy Acids)
AHAs are water-soluble acids that work on the skin’s surface to dissolve dead skin cells, making them a great option for dullness, uneven texture, and hyperpigmentation.
Common AHAs include:
- Glycolic Acid
- Lactic Acid
- Mandelic Acid
- Tartaric Acid
- Malic Acid
BHAs (Beta Hydroxy Acids)
BHAs are oil-soluble acids, meaning they can penetrate into your pores to dissolve excess oil and debris. That’s why they’re often recommended for oily, acne-prone, and congested skin.
The most common BHA in skincare is:
- Salicylic Acid
You may have also seen ingredients like retinoic acid, hyaluronic acid, ferulic acid, ascorbic acid (vitamin C), and azelaic acid. Although they all have “acid” in their names, they are not AHAs or BHAs. Each belongs to a different category of skincare ingredients and works in its own unique way. I’ll be covering those in future installments of this series.
Why Should You Exfoliate?
Exfoliation is one of the easiest ways to help your skin look brighter, smoother, and more even. It works by removing dead skin cells from the surface of your skin, which can improve texture, help fade the appearance of post-acne marks and dark spots over time, and encourage healthy skin cell turnover. Regular exfoliation can also help your other skincare products absorb more effectively.
There are two main ways to exfoliate:
- Physical exfoliation, which uses something abrasive like a facial scrub or exfoliating tool to manually remove dead skin cells.
- Chemical exfoliation, which uses ingredients like AHAs and BHAs to dissolve the bonds holding dead skin cells together, allowing them to shed naturally.
While both methods can be effective, many people find chemical exfoliation to be gentler because there’s no scrubbing involved. Instead, the acids do the work for you. If you’re dealing with acne, clogged pores, or rough texture, a chemical exfoliant can be a great addition to your routine.
What’s the Deal With Salicylic Acid (BHA)?
Salicylic acid is the most well-known Beta Hydroxy Acid (BHA) and a favourite for anyone dealing with excess oil, blackheads, whiteheads, or breakouts.
Who Is It Best For?
Salicylic acid works for most skin types but is especially beneficial if you have:
- Oily skin
- Acne-prone skin
- Congested pores
- Blackheads and whiteheads
What Does Salicylic Acid Do?
Unlike AHAs, which work mainly on the skin’s surface, salicylic acid is oil-soluble, meaning it can travel inside your pores to dissolve excess oil, dead skin cells, and debris that can lead to breakouts. It also has anti-inflammatory properties, making it helpful for calming angry pimples and reducing redness.
Salicylic acid can help:
- Unclog pores
- Reduce blackheads and whiteheads
- Improve breakouts
- Smooth skin texture
- Minimize the appearance of enlarged pores over time
- Promote healthy skin cell turnover
How to Use Salicylic Acid
You’ll find salicylic acid in cleansers, toners, serums, spot treatments, masks, and moisturizers. How often you use it depends on the product and its strength.
If you have oily skin, you may be able to use a salicylic acid product daily, while those with dry or sensitive skin may prefer using it a few times a week. If you’re new to chemical exfoliants, it’s always a good idea to start slowly and build up your usage as your skin adjusts.
And one reminder: always wear sunscreen during the day when using exfoliating acids, since they can make your skin more sensitive to the sun.
Personally, my skin gets along really well with salicylic acid. Whenever I’m dealing with congestion or the occasional breakout, it’s one of the ingredients I reach for because it helps keep my pores feeling clear without being overly harsh.
Here Are Some of Our Favourite AHA & BHA Products
La Roche-Posay Pimple & Acne Cream, Effaclar Duo
If you’re in Canada or Europe, La Roche-Posay Effaclar Duo is formulated with salicylic acid (BHA) and can be used either as an all-over treatment or as a targeted spot treatment, depending on your skin’s needs. It also contains hydrating ingredients, so it’s generally less drying than many traditional acne treatments.
The U.S. version, however, is a completely different formula. Instead of salicylic acid, its main active ingredient is benzoyl peroxide, making it more of a traditional acne spot treatment. If you’re in the U.S. and are looking for something that’s closer to the Canadian and European formula, Effaclar K is the better comparison, as it also focuses on gently exfoliating and unclogging pores. Have no fear, I have found the US version of this product, and it’s the Effaclar K. The Canadian and European versions of the Effaclar Duo can be used as an all-over-the-face treatment or a spot treatment. All versions are gentle enough to be both and have some other great hydrating skincare properties, so it won’t dry out your skin like many acne-fighting products can.
Kate Somerville EradiKate Acne Treatment
The Kate Somerville EradiKate Acne Treatment uses sulphur as its star ingredient, which helps target acne-causing bacteria while encouraging skin cell turnover. It also contains calamine, which helps calm and soothe inflamed breakouts.
It is a powerful spot treatment, so a little goes a long way. My one complaint is that it’s fairly high in alcohol, which can make it quite drying—especially if you already have dry or sensitive skin. It can also sting when applied to active breakouts, so don’t be surprised if you feel a bit of a burn for the first few seconds.
Beauty Pie Plantastic Micropeeling Super Drops
This AHA/BHA treatment is one of my favourite exfoliating products I’ve tried. It combines both types of acids into one formula, helping to smooth texture, clear congestion, and leave skin looking brighter without feeling overly harsh. My skin always looks glowier after using it, and I never get that tight, stinging feeling that some acid treatments can cause.
It’s designed to be used as an all-over treatment and works well for a variety of skin types, though I think those with oily or congestion-prone skin will appreciate it the most.
Beauty Pie products can seem expensive at first glance, but if you’re a member, you’ll pay significantly less than the listed retail price. Unfortunately, Beauty Pie still doesn’t ship to Canada, but I’m hopeful that will change in the future.
Glycolic Acid (and Other AHAs) You Should Know About
If your goal is brighter, smoother, glowier-looking skin, glycolic acid is one of the best ingredients to have on your radar. It’s the most well-known Alpha Hydroxy Acid (AHA) and is loved for its ability to exfoliate the surface of the skin, helping to improve dullness, uneven texture, and the appearance of dark spots over time.
Many AHAs, including glycolic, lactic, malic, and tartaric acid, are naturally derived from fruits, milk, or sugars. Because they’re water-soluble, they work on the skin’s surface rather than inside your pores as BHAs do. They’re also known for attracting water to the skin, so some AHAs can provide hydrating benefits in addition to exfoliation.
If glycolic acid feels too strong for your skin, lactic acid is an excellent alternative. It’s generally considered gentler while still delivering smoother, brighter-looking skin.
One thing to remember is that not all acid products are created equal. The strength of the formula matters, and higher concentrations aren’t always better. Stronger acids can be more irritating, especially if you have sensitive skin or are new to chemical exfoliation. That’s why it’s important not to overdo it. Healthy skin is all about balance, and over-exfoliating can damage your skin barrier rather than improve it.
How to Use Glycolic Acid
You’ll most commonly find glycolic acid in toners, but it’s also available in serums, cleansers, masks, exfoliating pads, and overnight treatments.
How often you should use it depends on both the product and your skin. Some formulas are gentle enough for daily use, while others are designed to be used just once or twice a week. Always follow the directions on the packaging, especially if the product contains a higher percentage of glycolic acid.
Personally, I have sensitive skin, so I stick to using glycolic acid just a couple of times a week rather than every day. It gives me the brightening benefits without pushing my skin too far.
And one last reminder: never skip sunscreen when using AHAs. These exfoliating acids can make your skin more sensitive to UV rays, so wearing a broad-spectrum SPF every morning is essential. Not only does it help protect your skin, but it also prevents new dark spots from forming and allows you to get the most out of your exfoliating products.
Here Are Some of the Best Glycolic Acid Products:
Biologique-Recherche Lotion P50
If I could only recommend one exfoliating toner, Biologique Recherche Lotion P50 would be at the top of my list. It’s one of those products that has earned its cult status for a reason. I’ve been using it for years, and it’s genuinely one of the most impressive skincare products I’ve tried.
It’s also a little elusive. You won’t find it at Sephora or most beauty retailers because Biologique Recherche is primarily sold through authorized spas and clinics. While some online retailers carry it, the brand prefers to keep distribution fairly exclusive. Depending on which formula and bottle size you choose, Lotion P50 is definitely an investment, with the larger 250 mL bottle typically costing well over $100.
Despite the name, Lotion P50 isn’t actually a lotion—it’s an exfoliating toner. Developed by the French skincare brand Biologique Recherche, there are several versions designed for different skin types and concerns. The original Lotion P50 1970, which contains phenol, is only available in the United States, while the formulas sold in Canada and Europe are phenol-free.
Don’t expect overnight results. Like most good skincare, this is a product that works gradually. With consistent use, I noticed smoother texture, less congestion, and healthier-looking skin overall. Depending on which version you choose, the formula contains a blend of exfoliating ingredients such as lactic acid, salicylic acid, and even vinegar (yes, really), all working together to gently exfoliate and improve the look of your skin over time.If I could only recommend one exfoliating toner, Biologique Recherche Lotion P50 would be at the top of my list. It’s one of those products that has earned its cult status for a reason. I’ve been using it for years, and it’s genuinely one of the most impressive skincare products I’ve tried.
Pixi Glow Tonic
Pixi Glow Tonic is another cult-favourite that, in my opinion, lives up to the hype. This glycolic acid toner is a great option if you’re looking to add gentle chemical exfoliation to your routine. It helps remove dead skin cells, leaving your complexion looking smoother, brighter, and more radiant over time.
Alongside glycolic acid, the formula includes soothing ingredients like aloe vera and ginseng, which help balance out the exfoliating effects so it doesn’t feel overly harsh. If your skin tolerates it well, you can use it regularly, but as with any exfoliating acid, it’s always best to introduce it gradually and follow the directions on the bottle—especially if you have sensitive skin.
If your skin is looking a little dull, this is one of those products that can help bring back that healthy glow.
Beauty Pie Fruitizyme +AHA 5-Minute Miracle Facial Peel
This Beauty Pie Fruitizyme + AHA 5-Minute Miracle Facial Peel is one of my favourite products to reach for when my skin needs a quick refresh before an event or special occasion. If your complexion is looking a little dull, this mask gives it an instant boost with just five minutes of wear.
I usually apply it before hopping in the shower or while I’m doing my hair, then rinse it off before starting my makeup. It leaves my skin looking noticeably smoother, brighter, and glowier.
The formula combines AHAs and BHAs with pomegranate enzymes and bamboo powder to gently exfoliate and smooth the skin, making it a great option when you want that fresh, just-had-a-facial look without spending much time.
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