Acids explained! How to use AHAs and BHAs to improve your skin and hair

Even if you're familiar with the concept of using acids on your skin and hair, it can still sound daunting. But don't let the name fool you — acids are a powerhouse beauty ingredient that deserve a place in every care regimen.

Our aesthetic experts reveal everything you need to know about using acids in your beauty routine. They share which acids are most common, what they do, and how you can use them to improve your complexion and hair health. It's time to erode some myths!

What are acids used for, and how do they work?

Acids are used as an exfoliating ingredient in skincare and haircare products. You can use them to remove dead skin cells, hydrate, and much more besides!

Skincare acids work by loosening the desmosome bonds that glue your skin cells together, allowing you to sweep away the dead top layer of the epidermis to reveal the fresh layer beneath. You're likely to see two main types of acid in facial peels and beauty products:

Alpha hydroxy acids

Alpha hydroxy acids (AHAs) are a family of water-soluble acids which occur naturally in certain plants and fruits. AHAs work on the surface of the skin, which makes them good for treating sun damage and pigmentation. Their surface-level penetration also makes AHA chemical peels and glycolic peels ideal for people who can't afford to take much downtime after a treatment. Instead, you can opt for multiple treatments over a longer time period.

Types of AHAs include:

  • Lactic – a mild acid used to treat hyperpigmentation.
  • Glycolic – AHA superstar capable of hydrating while exfoliating.
  • Tartaric – both an antioxidant and a hydrating exfoliant.
  • Azelaic – anti-inflammatory and antimicrobial acid.
  • Malic – a gentle exfoliant best suited to sensitive skin types.
  • Citric – brightening exfoliant and antioxidant.

Beta hydroxy acids

Beta hydroxy acids are natural, oil-soluble acids which penetrate deep into the skin to improve the appearance of fine lines and texture. BHAs are thought to be less irritating than AHAs, and their antibacterial effects make them good for acne sufferers.

The most popular BHA for skincare is salicylic acid, which exfoliates while decreasing redness and swelling. Trethocanic and tropic acids are also classed as BHAs, but they're less common in beauty products.

When used as part of a facial peel, BHAs give a deeply penetrating cleanse, which often requires several days of downtime. You'll need to be gentle with your skin afterwards, only using mild cleansers and products recommended by your facialist.

If you're familiar with your acids, you might be wondering why hyaluronic isn't included in that list. Although it may have 'acid' in the name, hyaluronic isn't actually an acid; it's a moisture molecule that occurs naturally within the skin.

BHAs and AHAs aren't just a great ingredient for home-care products; they're also widely used in specialist skincare treatments. In fact, booking an appointment with an aesthetic expert is a great first step when integrating acids into your beauty routine. They'll advise the best products for you and can kickstart your journey with a deep cleansing AHA or BHA peel.

How to choose an acid peel facial at Paul Edmonds London

We've stocked our skin destination with a curated edit of clinically-proven brands. Here are some of the peel options available and how to choose a treatment based on your needs.

SkinCeuticals Peel


There are three SkinCeuticals peels at our skin destination, each designed to address specific skin types and issues. The Glycolic Peel stimulates collagen and promotes radiance with light exfoliation. If you need slightly more exfoliation, opt for the Micro Peel to target fine lines, dullness, and imperfections. Finally, we recommend the SkinCeuticals Pigment Balancing Peel to target hyperpigmentation and sun damage.
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Acne Peel

ZO Skin Health

Need quick results for an upcoming event? Book our Stimulator Peel — it's specially formulated for that instant, short term radiant glow. After an initial glow period, this peel causes the skin to shed, revealing a glowing visage once more.
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Decree Peel

Decree Weekly Peel

The Decree Weekly Peel is an at-home product that makes a fantastic add-on to our Decree facial. It's a clinical-grade peel powerhouse that combines AHAs and fruit enzymes to resurface and hydrate the skin.
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Before and After

TCA chemical peels

Trichloroacetic acid (TCA) peels are a great option for anyone suffering from skin complaints deeper in the epidermis. TCAs have a lower PH than other peels, which means they penetrate much deeper to target pigmentation and ageing. 

Our skin destination offers TCA peels in synergy with our aesthetics practitioner, who'll work with aestheticians to create a pre-peel program to help build your tolerance. These programs usually last for an entire skin cycle (4 to 6 weeks). Prepping ahead of the peel allows for a quicker recovery time, less dramatic inflammation, and better results.

Book your peel

LED Light Therapy

Can you have other services with acid facial peels and treatments?

Yes absolutely. In fact, this is a great time to opt for other treatments because your skin is clear of dirt and debris. We recommend combining your peel with other anti-ageing services like mesotherapy and microdermabrasion. LED light therapy is also a great follow-up service for acid peels because it targets specific concerns, like pigmentation.

Are you a fan of filler or Botox? Combining non-surgical aesthetics services with a peel helps to target the shape and elasticity of the skin, alongside the quality and brightness. All clients who book a course of Botox or Profhilo get a complementary GL peel with our aestheticians (which makes the deal even sweeter!).

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Using acids in your hair and beauty routine at home

Acid skincare

Team your chemical peels and aesthetic procedures with SkinCeuticals Glycolic Renewal Cleanser, designed to be the perfect partner to in-clinic treatments. If you want to bump up the potency and renew skin overnight, we recommend SkinCeuticals Glycolic 10 facial cream.

Take advantage of the foaming, exfoliating lipo hydroxy acids in SkinCeuticals Blemish + Age Cleansing Gel as part of your oily, acne, or anti-ageing skincare routine. Amp up the potency by choosing Blemish + Age Defence treatment, which harnesses the power of salicylic acid and dioic acid to control breakouts and smooth imperfections.

Acid haircare

Your hair and scalp can reap the benefits of acid-based products, too. Use the tartaric acid in the Kérastase Chroma Absolu range to prevent minerals from dulling the shine in your coloured hair. 

Do you suffer from dry hair and scalp flaking? Hydrate with hyaluronic acid-packed Kérastase Pré-Cleanse Régénérant and give yourself a moisture boost. If you're plagued by oily roots, we recommend the salicylic acid-rich Kérastase Bain Divalent shampoo to rebalance your scalp. 

You can combat oily and dry flakes by using Kérastase Bain Anti-Pelliculaire shampoo. It uses salicylic acid to target the bacteria responsible for dandruff and can clear flakes in as little as 8 weeks.

Now that you know your AHAs from your BHAs, you're ready to revamp your beauty routine! Book yourself in for a facial peel at our skin destination or shop your new obsession online to start reaping the benefits of acids.