Skincare ingredients list has you stumped? Consider this your go-to guide to acids.
While the thought of smoothing acid on to your skin may sound scary, this multi-tasking ingredient family could be the secret to unlocking your most radiant complexion yet.
Not all acids are created equal, and many
Each one performs a different function when applied to the skin – from banishing blemishes and balancing oiliness to plumping fine lines or soothing inflammation.
By now, most of us will have heard of the common skincare acids – hyaluronic, salicyclic, ascorbic – but there’s a whole host of lesser-known options that are worthy of a spot in your skincare rotation.
However, understanding the difference between them, how they work and which skin types they’re best suited to can often feel like a daunting task.
To cut through the confusion, we enlisted the help of a skincare expert to shed light on the different types of acids, and how best to incorporate them into your routine.
What’s the difference?
Typically, the use of acids in skincare points to chemical exfoliants – found in cleansers, toners, serums, moisturisers and eye creams.
According to Nathan Rivas, beauty brand Drunk Elephant’s vice-president of global research and product development, most acids approach exfoliation in a similar way – resurfacing dead skin cells and retexturising the skin, leaving it with a healthy glow.
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Advertise with NZME.He says the primary difference lies in their solubilities (or how a substance dissolves into skin).
“Alpha hydroxy acids are purely water soluble, so they can’t really go beyond that first layer [of skin],” Nathan says.
“Polyhydroxy acids have a higher rate of solubility than alpha hydroxy acids, so you have some blemish-fighting benefits that are not possible with just first-generation alpha hydroxy acids.”
By contrast, beta hydroxy acids are oil-soluble, meaning they’re better at penetrating the follicle and addressing skin issues like congestion.
Alpha Hydroxy Acids (AHAs)
Common acids: Glycolic, lactic, citric and mandelic
What they are: AHAs are water-soluble acids, meaning they exfoliate the skin’s surface to varying degrees.
Glycolic remains one of the most common AHAs, found in skincare touted to remove the top layer of dead skin cells to banish dullness and leave skin brighter and more radiant-looking.
While it’s suitable for most skin types, those with dry or sensitive skin may want to select a lower concentration glycolic to avoid irritation. Instead, lactic and mandelic acids are gentler. They lightly exfoliate skin but are less likely to leave redness in their wake.
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Beta Hydroxy Acids (BHAs)
Common acids: Salicylic
What they are: BHAs remain a popular choice for combination/oily skin types, thanks to their ability to exfoliate clogged pores and decongest skin.
Salicylic acid is the most common BHA, but Nathan adds there are new ways of using it to maximise its anti-inflammatory properties.
“Salicylic acid is a chemical cousin of aspirin, which is acetyl salicylic acid. And so as a result, there is a potential in there to bring out some of those anti-inflammatory benefits if you formulate it properly,” he says.
Nathan notes betaine salicylate as an ingredient to watch – which can be formulated alongside salicylic acid to boost its efficacy without increasing the potential for irritation.
Polyhydroxy Acids (PHAs)
Common acids: Gluconolactone and lactobionic
What they are: PHAs are larger in molecular size than AHAs or BHAs, meaning they penetrate the skin’s surface slowly and gently. Their inability to absorb into the deeper layers means they’re ideal for sensitive skin types.
“The great thing about polyhydroxy acids, particularly gluconolactone, is that they have a higher rate of tolerance than your classic alpha hydroxy acids, even though they are at a similar rate of benefit equivalency and percentages,” says Nathan.
Try: The Ordinary PHA Exfoliating Lip Serum, $17 (available from September 24) and Aesop Lucent Facial Refiner, $133.
Other Types Of Acids
While they’re not categorised as AHAs, BHAs or PHAs, these acids boast their own benefits.
Hyaluronic Acid: A powerful humectant which can draw up to 1000 times its weight in water to the skin (and keep it there). This molecule is found in everything from cleansers to serums to moisturisers and boasts universal appeal to all skin types (particularly good for dry or dehydrated skin). Try La Roche Posay Hyalu B5 Serum, $59, which replumps the skin and increases elasticity.
Ascorbic Acid: Also known as L-Ascorbic acid, this form of vitamin C helps fend off free radical damage, inhibiting melanin production and reducing dark spots, leaving skin more even-toned and radiant. Try Jeuneora Brightening Booster, $45, which helps to brighten skin, reduce the appearance of dark spots and fend off environmental damage.
Amino Acid: A must for a healthy skin barrier, amino acids maintain the skin’s hydration, resilience and health. This hardworking molecule promotes collagen, cellular repair and regeneration in the skin, meaning it appears more even in both tone and texture, with a reduction in fine lines and wrinkles. Find it in the new Drunk Elephant Amino Acid Rain Glasswater Serum, $114, which boosts luminosity, firms and soothes skin for a glass-skin finish.
Retinoic Acid: Retinol or vitamin A comes in many forms, and is said to stimulate cell turnover and boost collagen production in the skin, improving elasticity and firmness whilst refining skin texture when used over time. It’s powerful when cocktailed into serums touted to smooth fine lines and wrinkles, resulting in a smoother, firmer complexion. Try Kiehl’s Retinol Micro Dose, $189, which harnesses a precise amount of retinol to help build tolerance over time.
How to apply acids in your skincare routine
Nathan recommends a slowly-slowly approach if you’re new to acids, explaining skin tolerance differs for everyone.
“Someone who’s completely new to actives would baby-step in. They would start with their moisturiser and hydrator, and start with their core active, whether it’s glycolic acid or beta hydroxy acid or retinol,” he says.
“When it comes to adding other actives, they could use it once a week or every other day, and carefully evaluate how their skin responds. Over time, they can increase the frequency until they find that sweet spot that gives them the results they want without compromising their skin barrier.”
There’s no one-size-fits-all rule when it comes to using active ingredients like acids, Nathan says, adding some people can use exfoliating acids twice daily and others can only use them once a week.
And if you do have a mild reaction like redness or irritation? Nathan says to strip your skincare routine right back and stick to a basic cleanser, moisturiser and sunscreen.
“Continue with this basic routine until whatever reaction you’ve encountered subsides entirely,” he says, warning that any reaction accompanied by swelling should be assessed by a medical professional.
“When that redness has gone away, introduce that product in your routine at a frequency slower than what you did before – once a week, three times a week, every other day – and assess from there.”
The key is to be patient, Nathan says, allowing time for tolerance to be built up and fine-tuning frequency to experience the formula’s full benefits.
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