BHAs: How and Why You Should Be Using Them

MECCApedia is here to decode the science, unravel the jargon and give you the knowledge to understand the actives you're slathering on morning and night. Let your skincare education commence!

Make way, make way, BHAs are clearing the path towards smooth, glowing skin. Short for beta hydroxy acids (if we were testing you, this would be question one), they hold impressive pore-clearing abilities and could be the ingredient your skincare routine is missing.

They are popular chemical exfoliants that you may have come across alongside AHAs (alpha hydroxy acids). Both offer a helping hand in shedding dead skin cells to support cell turnover. The result? Fine lines appear less prominent, skin tone more even, and a radiant glow awaits. Plus, your addictively soft skin preps a blank canvas to allow your skincare routine to go the extra mile. You heard us right! What makes BHAs truly special is their ability to sink even deeper into the pores to further clear excess oils and debris. So if you have oily or blemish-prone skin, you may want to add them to your roster.

Once you get behind the technical talk, they are easy to include in your routine. So pens out, here is everything you need to know.

Beta hydroxy acids are a chemical exfoliant; unlike the physical scrubs of our teenage years, they don't rely on abrasive particles to get the job done. They start their work on the skin's surface, buffing away dead skin cells by dissolving the glue that holds them together. Their oil-soluble structure means they don't allow oily substances to stand in their way and can get past excess oils and the skin's lipids to get deeper into the pores. Clever, right? The most common BHA found in skincare is salicylic acid, the infamous blemish-buster naturally found in the barks of willow trees. Some of our favourite brands turn to the pore-patroller in their formulas, and it has earnt its way into our routines in the forms of blemish treatments, cleansers, serums and body scrubs.

The exfoliating power of a BHA brings about a transformative result; we like to describe it as 'uncovering your glow from within'. By assisting dead skin cells to shed, the shiny new ones beneath (unexposed to harmful external factors like sun exposure) take centre stage. Over time, this can improve the appearance of fine lines, create a more even-looking skin tone and leave a radiant complexion in its place.

Thanks to its ability to get past lipid layers and sink deeper into the skin, the ingredient can work its magic on the lining of the pore. Once penetrated, it dissolves the debris clogging the pores which will allow natural oils to flow more freely. The rest of your routine will also thank you for it; with less standing in their way, your skincare products can also get deeper into the skin, enabling them to work a little harder. Did someone say skincare hero?

You will find BHAs making their way into skincare formulas in the form of topical spot treatments, rinse-off cleansers, exfoliating peel pads and leave-on serums. Salicylic acid is the most common form of BHA found within cosmetic products, the main difference being the concentration used which ranges between 0.5%-5%. Those products designed for everyday use, such as a cleanser, will generally have a lower acid concentration. A leave-on exfoliator may contain higher percentages, so they should be used less frequently. The benefits may be tempting enough to get application-happy, but patience is key and it is essential to check the concentration of BHA and the recommended frequency of use. Whilst the back of the bottle is always a good place to start, we recommend building up usage slowly or even testing the product on a small patch of skin to avoid unwanted reactions (heart reacts only!).

It's no surprise that BHAs are especially beneficial if you have oily or blemish-prone skin. Their ability to sink deeper into the skin will help clear congested pores, bringing you closer to stopping new blemishes and blackheads in their tracks and managing the symptoms of those already there. Plus, their oil-soluble trait enables them to pass through and dissolve excess oils (AKA the culprit of midday shine) while allowing the necessary, skin-loving amount to flow freely. Take this as a sign to get on the BHA wave (if you haven't already!).

Using acid on your face may sound scary, but BHAs are actually gentle on the skin (a reminder not to judge a book by its cover). This means sensitive skin types could also join the BHA party and benefit from assisted cell turnover. But it is essential to remember that BHAs are still considered an active ingredient; you should take extra steps in carrying out patch testing before starting with a low concentration and building up your tolerance. If your skin is dry, it’s best to opt for an AHA formula as it will allow your skin to retain that much-needed moisture.

So the long list of benefits were enough to convince you to incorporate BHAs into your routine, but patience really is key as you don’t want to cause dryness or irritation by starting too strong. Begin your BHA journey with a low concentration rinse off cleanser every other day to allow your skin to adjust to the acid. If you have sensitive skin and your skin tolerates the acid then you can continue with this daily.

If you have oily skin, you can take things further and experiment with a leave-on BHA toner that can be applied with a cotton pad after cleansing to dry skin. You can then go in with the rest of your serums and moisturisers. This is a great choice for combination skin, too as you can apply this topically to areas that feel greasy like the t-zone and chin whilst avoiding dry patches.

You could also opt for a moisturising gel or lotion containing BHAs that can be applied as you would a day or night cream. If your skin continues tolerating the ingredient, you can work your way up to a BHA peel that is likely to contain a high acid concentration; always check the label for recommended use, but we like using this at night and limiting use to once a week (like during your Sunday reset!).

You will often find that products pair BHAs alongside an AHA. It's no surprise; side by side, they are a dynamic duo that offers deep exfoliation, but these should be used cautiously to avoid over-exfoliating the skin. Niacinamide is another A-list ingredient in an oily skin routine, albeit working slightly differently from BHAs, so combining the two can reap impressive results. Niacinamide reduces excess oils by stabilising oil production, which reduces the appearance of pores whilst contributing to a protected skin barrier (which can increase the likelihood of your skin tolerating the acid).

Tread carefully when incorporating BHAs into a routine that involves other actives like vitamin C or retinol. Overloading the skin with potent ingredients can take the fun out of skincare, lead to a compromised skin barrier, and land you in irritation station. We recommend using your actives on different days and introducing all ingredients slowly to find what works best for you.

Over-exfoliation is real and can compromise your skin barrier. Key signs you are overdoing it? Dryness, irritation and unexpected breakouts. With this in mind, it is best to avoid using more than one type of BHA product at a time or going above the recommended use. If you are unsure about whether you can use BHAs (like if you are pregnant, breastfeeding or taking medication) it is best to consult a doctor before use.

Last but not least, it wouldn’t be a lesson in skin school without a final reminder to use SPF daily (whether you are using BHAs or not, it is a non-negotiable). Whilst using BHAs and assisting with skin cell turnover brings about many benefits, the newer skin cells will be extra sensitive to the sun, so it really is essential to ensure you are applying and reapplying SPF throughout the day. Your skin will thank us later!

Transient stinging or irritation may occur when using BHA products. If irritation persists, discontinue use. Not recommended for use on children or infants.