Do you know your AHAs from your BHAs? The Definitive Guide To Skin Acids

By Tamara Corin | 17th November 2022
skin acids

While it may sound daunting, using face acids instantly elevates your skincare routine. Acids are the mega multi-taskers that bring a whole host of skincare benefits by renewing the skin’s cell turnover, whether your concerns are ageing, acne, pigmentation, or dryness.

“Acids are incredible ingredients that are extremely effective, and their effects can be seen very quickly on the skin,” says Dan Isaacs, head of research and development at skincare brand Medik8. “You’ll see substantial changes in the skin’s texture in as little as a week, with results improving over time.” Dead skin cells absorb light rather than reflect it, so the cleaner and fresher your skin’s surface, the glowier and healthier your complexion.

Going back to basics. Typically, there are two main types of skincare acids, AHAs (alpha hydroxy acids) and BHAs (beta hydroxy acids). AHAs are water-soluble exfoliants and work to dissolve dead skin cells, whilst BHAs are oil-soluble, meaning they can penetrate clogged pores more easily. But just to confuse us even more, within these categories are sub-categories that are specific to your skincare concern and skin type.

Here, we give you the lowdown minus the fluff on the big hitters that should be part of your skincare staples…

Glycolic Acid

This is a great intro into the world of face acids and brilliant at dusting off those dead skin cells that sit on the surface of your skin. Glycolic is also known for helping the appearance of skin discolouration, and those pesky fine lines and wrinkles. AHA rich this acid is gentle but hardworking and compared to other acids, glycolic has the smallest molecules so it penetrates the skin easily giving dramatic results. Use twice a week for a solid skin dust and choose products that contain 10% glycolic, which is suitable for daily use and will effectively target your main skin concerns. And although glycolic acid is gentle, it can make skin sensitive to sunlight, so save using it for your evening routine.

Lactic Acid

Another strong member of the AHA gang, lactic acid simultaneously increases moisturisation while also gently exfoliating skin. Because of its moisturising properties, it is a milder form of glycolic acid and great for soothing sensitive skin without irritation. Its molecules are bigger than those in glycolic, so don’t penetrate as deeply which can often trigger that peeling action which is too harsh for sensitive skins to cope with. Naturally formed from fruit sugars and milk, it has a mild yogurt-y scent but not at all overwhelming. Cleopatra was definitely ahead of the skincare game with her bathing in milk beauty ritual!

Mandelic Acid

This is the quieter acid from the AHA family, but just as effective as glycolic at treating pigmentation from sun damage, but with less redness and irritation. Derived from almonds, this is a go-to for anti-ageing, it works by removing dead cells from the skin’s surface while strengthening collagen. Mandelic’s molecules are twice the size of glycolic’s and a third bigger than lactic’s, so irritation is reduced, as it takes a long time to penetrate the skin yet it’s the only acid that works deep in the skin’s layers that slows down melanin production. It also has anti-bacterial properties and helps regulate sebum production making this a brilliant choice of AHA for acne-sufferers and oily skin types.

Salicylic Acid

If you want to bust spots and acne in the face, salicylic acid is an absolute must! As a BHA it can penetrate through the skin’s surface, unclogging pores and wiping up oil in its path while making skin appear not only clearer but plumper too. It’s also a great anti-inflammatory agent, which is why you’ll often find it in spot gels and acne treatments. Look for strengths that are 0.5% to 2% which is gentle enough to flush out dirt and debris every day.

Azelaic Acid

This naturally occurring acid can be found in grains such as barley and rye, it’s a great choice for skin types that suffer from breakouts, spots, and sensitivity as its natural base means it is highly tolerable and offers a softer approach to exfoliation.

L-Ascorbic Acid

Otherwise known as Vitamin C, this super potent antioxidant fights off free radicals and other environmental aggressors while giving skin the most luminous glow, every time. Packaging is key when choosing a L-ascorbic acid-based product because as soon as it’s exposed to sunlight, heat or air the stability of the Vitamin C is ruined and becomes completely useless. Look for single-dose packaging or innovative bottle designs that ensure the Vitamin C is stable. Use twice daily and you’ll quickly make dull lacklustre skin a thing of the past.

Hyaluronic Acid

Last but by no means least, this popular acid is widely recognised and often used without realising. Neither an AHA nor BHA, hyaluronic acid occurs naturally in your body. As we age, our bodies slow down the production of hyaluronic acid and then the tell-tale signs of ageing start to creep in. The wonder of this acid is that it has an incredible ability to hold over 1,000 times its own weight in water. A daily dose or twice daily if you fancy, will plump, hydrate, and give you that lit-from-within glow.

Don’t forget…regardless of whether you’re applying an acid or not, a hardworking SPF is a necessity for extra skin protection during the day. In particular AHA’s and sunscreen go hand in hand. Here’s some of our top sunscreen saviours.

The products on this page have been selected by our editorial team, however, The Handbook may make a small commission on some products purchased through affiliate links.

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