The Acid Test

Do you know your AHA from your BHA?

Words by Sorcha McCoy Moran
April 24th, 2017

Whether you’re a skincare aficionado or maintain a restrained routine, chances are you’re using an acid at some point each day. If you’re not, you should be.

Dermatologists cite retinoic acid as the second most effective anti-ageing product you can use, behind SPF. Beyond that, though many people are aware of them, there is such a proliferation of acids on the market that it’s easy to feel overwhelmed and confused by what’s right for your own skin. Whilst they can all deliver excellent results, knowing your AHAs, BHA and Hyaluronic Acid apart is key when incorporating acids into your arsenal. Here is a quick rundown of the most effective acids available.

Alpha Hydroxy Acids (AHAs)

Example: Glycolic, Citric, Lactic.

The most commonly used of acids are derived from fruit, nuts, milk or sugars. They’re hydrophilic, meaning they’re attracted to water. As AHAs are such tiny molecules, they can penetrate the epidermis much more deeply and gently than abrasive scrubs, making them the best exfoliators. They brighten skin, aiding in cell turnover and collagen production and can also be used to reduce hyperpigmentation. Be sure to wear an SPF as acids make skin more photosensitive.

How to use: AHAs are water-soluble, so apply your cleanser, toner or treatment serum/mask to completely dry skin as skin that is damp will hinder the product’s effectiveness.

Best for: Brightening dull skin, first signs of ageing, fine lines.

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Beta Hydroxy Acid (BHA)

Example: Salicylic Acid

These are derived from acetylsalicylic acid, better known as aspirin. They are lipophilic, meaning that they’re attracted to oil and thus a great choice for oily and/or acne-prone skin. They penetrate and dissolve the oil, debris and dead skin which may be congesting the skin’s pores. While not quite as effective as AHAs at exfoliating, they soften and even the skin surface by virtue of this pore purging.

How to use: BHAs are oil soluble, so should be applied to skin which is freshly cleansed and dried. You can use a salicylic toner or a standard toner followed by a separate BHA product, such as a serum or pads. If using a separate BHA product, leave it on for about 2 minutes to absorb before applying moisturiser.

Best for: Oily and/or acne-prone skin. Can also be used to great effect to treat isolated breakouts on any skin type.

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Glycosaminoglycans (GAGs)

Example: Hyaluronic Acid

Despite the name, Hyaluronic Acid is a humectant, meaning it attracts and retains moisture. It occurs naturally in the body and is integral to maintaining healthy, hydrated skin, with 1g of HA able to hold up to 6 litres of water. As we age, our skin gradually loses this ability to retain moisture leading to a reduction in firmness, plumpness and the exaggeration of the appearance of lines. Thus, every skin type can benefit from supplementing their skincare regimen with a hyaluronic as it is an extremely gentle instant injection of moisture.

How to use: Apply to cleansed, dry skin in a moisturiser with Hyaluronic Acid. Alternatively, and especially for particularly parched/dehydrated skins, try incorporating a standalone Hyaluronic Acid serum before moisturising. Hyaluronic acid masks are also a pleasant, indulgent night time treat.

Best for: All skin types, especially dehydrated.

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Retinoic Acid (Vitamin A)

Example: Retinols

Technically, Retinoic Acid is only available as a prescription, but Retinol is a Retinoid meaning it is a derivative of this amazing acid and delivers similar and equally impressive results. It’s clinically proven to decelerate the process of skin ageing by normalising cell turnover where the cells would usually pile up, causing a dull complexion, i.e. it triggers cells to renew themselves more regularly. The result? Minimisation of fine lines and wrinkles, smoothing of the skin’s texture and a reduction in hyperpigmentation. They also boast some exfoliant properties which aids in keeping pores clean.

How to use: The single most important aspect of using Retinol is that you only do so at night, 3-4 times a week. Though it’s available in a variety of potencies, Retinol is strong and as Vitamin A is an active ingredient, it will irritate all skin types on initial application. It also normalises the outer layer of your skin making it more sensitive to the sun so ensure to be vigilant with your SPF usage. Apply retinol (as a serum or cream) after cleansing and toning, but before applying any other serums or moisturisers. Mild stinging and redness are normal. You should add Retinol to your night time routine incrementally, especially if you have sensitive skin, starting with a low strength such as 0.3% once a week and working up to 3-4 nights a week over time. Skinceuticals Retinol 0.3% is a good choice for beginners.

Best for: An anti-ageing powerhouse everyone from their late 20s/early 30s should be incorporating into their routine. Your future skin will thank you. Though it may take some trial and error, there is a Retinol out there for every skin type.

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