A complete guide to skincare acids

Have the winter months left your sun-starved skin feeling anything but sparkly? If the answer is yes, it’s time to start experimenting with skincare acids – the innovative liquids, serums, lotions and potions that have ascended to superhero status in recent years, as favoured by beauty junkies and skincare experts worldwide. But there’s a lot to unpack before you start your trip.

Let’s start with your A (alpha-hydroxy acids), B (beta hydroxy acids), Cs (vitamin C – more on this later) with a little help from Clara Croux, Product Development Manager at cult vegan skincare brand Typology.

Firstly, acids are not as invasive as you might imagine. As Croux explains: “Acids are several families of molecules that have different properties depending on their form and respond to a wide variety of skincare problems: exfoliating, anti-ageing, moisturising, antioxidants, etc.”

“It’s important to research which acids will work best for your specific skin type – and always do a patch test as a precaution”

Secondly, they’re really effective when used properly. For many beauty addicts, Pixi’s Glow Tonic was the gateway product for better understanding the positive exfoliating and brightening properties of acids, but it’s important to be informed before assuming that all acids have a place in your routine. Being overzealous with acids can lead to unhappy skin. While some experts suggest that acids shouldn’t be used daily for fear they will contribute to an over-exfoliation of the dermis, in turn damaging the skin barrier, others note that the frequent use of too many different kinds of acids might impair the healthy PH balance of your skin, resulting in rawness, breakouts and clogging. In worst-case scenarios, we’ve witnessed the results of acid misuse in cases such as Sarah Chaudry’s first-hand account of burning her skin with The Ordinary’s acid-laden skincare line.

In short, it’s important to research which acids will work best for your specific skin type – and always do a patch test as a precaution. A good rule of thumb when educating yourself is to remember that acids fall into two categories: AHAs (alpha-hydroxy acids) and BHAs (beta hydroxy acids). AHAs are good exfoliators and BHAs are best at unclogging the skin. For breakouts and oil regulation, look toniacinamide (otherwise known as Vitamin B); for pigmentation or discolouration you can try tranexamic acid, glycolic acid and lactic acid, while sensitive skin types will find PHAs and lactic acid useful.

Here’s everything you need to know to start, or supercharge, your skincare acid trip.

AHAs (alpha hydroxy acids)

AHAs are fruit and plant-derived acids. You can consider these the big hitters. Glycolic and lactic acids fall into this group, too – ingredients you may recognise from some of your skincare already.

Great for… anyone looking to improve the tone and surface of their skin, reduce any pimples, fine lines and to aid healing scarring.

Ideal for anyone… looking to fight the hands of time. Also for those who enjoy the tingly sensation that comes with deep exfoliation, shifting some dullness and improving the overall quality of their skin.

Expect to see… brighter, smoother skin and a newfound glow.

BHAs (beta hydroxy acids)

BHAs are very similar to AHAs but reportedly cause less irritation. Both groups of acids look to shed dead skin cells that make the surface of the skin appear dull and lined.

Great for… oily skin types looking to unclog pores, banish black heads and resurface the very top layer of skin (it’s a gentle exfoliator when used within skincare products). They’re great for shifting milia (tiny white “milk spots” that are sometimes found around the eyes, cheeks, lips and nose).

Ideal for anyone… looking to really de-clog their skin. While AHAs are water soluble, BHAs are uniquely oil soluble, allowing them to break down oil congestion and calm any inflammation that comes as a result of breakouts. Salicylic acid, one of the most recognisable acids from this family, is known to specifically combat acne.

Expect to see… brighter, calmer and less inflamed skin.

PHAs (poly hydroxy acids)

PHAs are some of the lesser known types of acids, but no less effective. Croux loves them because they provide “gentle exfoliation” allowing product developers to dial up the dosage for maximum efficacy. The molecules are larger, meaning they don’t disturb the skin beyond the surface.

Great for… anyone with sensitive skin who’s looking for a buffed and polished squeaky clean surface.

Ideal for anyone… who’s been burnt by AHAs or BHAs in the past (see Sarah Chaudry’s case above).

Expect to see… a gentle but impactful rejuvenation of the quality of your skin. Ideal for anyone suffering from raw, sensitive skin or rosacea.

LHAs (lipo hydroxy acids)

LHAs are less aggressive acids that are ideal for sensitive skin types. LHA is also known as capryloyl salicylic acid. According to La Roche-Posay, as a “derivative of salicylic acid, the major benefit of beta-lipohydroxy acid (LHA), lies in its gentle, non-irritating mode of exfoliation”.

Great for… anyone looking to combat acne without stripping their skin.

Ideal for anyone… who found salicylic acid too strong and is looking to take it slow with their acid routine. The PH level of LHAs almost matches that of healthy skin, so your skin barrier is safe.

Expect to see… any excess oil cleaned up, reduced pores and less blemishes. Some reports suggest LHAs have hydrating properties and are ideal for anyone looking to combat ageing and fine lines.

Ascorbic acids

Ascorbic acids are otherwise known as vitamin C. Vitamin C is your all-rounder: it brightens, hydrates and is a highly effective anti-pollutant. Ascorbic acids also help protect against UV damage.

Great for… pretty much everyone. It’s proven to promote collagen, lighten dark spots and help protect your dermis against pollutants.

Ideal for anyone… who wants to turn the brightness up on their skin care routine. You should notice an increased glow almost immediately. Word of warning: avoid using your acids with vitamin C in the mix. Both are acids, meaning they will work against each other giving you zero results. And while vitamin C and niacinamide can be used individually to combat acne, when mixed they can in fact trigger breakouts.

Expect to see… brighter, hydrated, more youthful looking skin.

Nellie Eden’s top tips for first timers:

So you’re embarking on your first acid trip? I recommend starting with what’s regarded as the hero acid by many beauty editors: hyaluronic acid (HA), which actually isn’t a true acid. Instead, it’s a naturally occurring glycosaminoglycan which is famed for its ability to “bind up to 1000 times its weight in water”, meaning it’s intensely hydrating and suitable for most skin types and for everyday use. Start by introducing your acid weekly and then at night before going to sleep. If you’re seeing results, progress to evening and morning use: apply your acid straight after cleansing, then finish with a moisturiser and SPF.