All About Acids

Exfoliating acids can be your skin’s superhero; they can exfoliate, smooth and visibly brighten many stubborn skin concerns. As some of the most well-proven ingredients in skincare, they have the potential to transform skin tone and texture in just a matter of weeks.

At Medik8, we have 3 categories of products and treatments containing exfoliating acids:

Daily Acid Exfoliation

At-Home Treatments

Professional Peels


Before we get into our different acid categories at Medik8, let's look at how they actually work. Exfoliating acids break down the bonds between skin cells to allow them to shed off more easily, helping to stimulate faster skin cell turnover. As a result, they can help to resurface the texture of the skin and minimise the appearance of hyperpigmentation. They can even reduce congestion and the likelihood of blemishes forming, all while smoothing the appearance of fine lines and wrinkles.

There are many different exfoliating acids to choose from, and it’s super important to tailor your ‘acid wardrobe’ (as we like to call it) to your individual skin type and concerns.


So let's meet our 3 types of exfoliating acids: AHAs, BHAs and PHAs. They all have different ways of working on the skin, all with slightly different end results.

AHA - Alpha hydroxy acid. Usually water soluble and work to exfoliate the upper layers of the skin. Examples include glycolic acid, lactic acid and mandelic acid - see Sleep Glycolic our true 10% glycolic acid at-home peel, or Pore Minimising Tonic which contains a blend of lactic and mandelic acid.

BHA - Beta hydroxy acid. Oil soluble and can therefore penetrate deep into pores, unclogging blockages to prevent blemishes. Examples include salicylic acid - found in our Blemish Control Pads, Blemish SOS and Press & Clear at a maximum strength of 2%.

PHA - Polyhydroxy acid. Water soluble, and are made up of big molecules therefore they stick to working on the top surface of the skin. Examples include gluconolactone - found in our everyday, twice a day acid toner Press & Glow.
So now we’ve established each type of acid - let's get into our different categories at Medik8.


When high strength exfoliating acids are used every day, multiple times a day, the skin can become overwhelmed. Over exfoliation of the skin can lead to an impaired skin barrier and, ultimately, sensitised and dry skin which is less able to repair and protect itself. We wanted to overcome this problem at Medik8, by developing exfoliating acid products that can be used in an everyday regime.

At Medik8, we have two clinically proven stars of daily acid toning: Press & Glow and Press & Clear. Born out of the need for powerful, exfoliating acid toners that can be used every day, twice a day, both formulations are non-drying, non-sticky and always gentle on the skin. Press & Glow and Press & Clear are suitable for all skin types, including sensitive skins. The perfect upgrade to your daily Medik8 regime.

Press & Glow features hydrating polyhydroxy acid gluconolactone (at 5.5%) and is designed to deliver radiant, glowing skin. It is perfect for those experiencing skin dullness, uneven texture and those wanting to boost their vitamin A results, due to its gentle, hydrating propertie

Or if skin clarity is your main concern, then our new-to-market Press & Clear is for you. Utilising the power of 2% salicylic acid with cutting-edge encapsulation technology, this toner provides triple-action blemish care that’s as powerful as it is gentle.

Both toners are ideal for use alongside your daily CSA routine.

Can you use multiple exfoliating acids together?

Overuse of high-strength AHAs, BHAs and PHAs everyday can leave the skin barrier impaired, leading to sensitised and dry skin. If you want to introduce an everyday, twice-a-day exfoliating acid to your routine, we recommend our clinically proven PHA toner, Press & Glow. Its carefully-curated ingredients boast hydrating and barrier-supporting qualities, a far cry from the common downsides of traditional exfoliating acids.

At Medik8, we advise against layering acids in a single routine. If you use too many exfoliating acids, your skin can become irritated and stripped of its natural moisture and oils. When layering your skincare, start with one exfoliating acid - either daily or every other day, depending on how sensitive your skin is. Work in other treatments throughout the week if your skin feels comfortable and always patch test first. Refer to for an in-depth guide to patch testing.

We recommend choosing one exfoliating acid (Sleep Glycolic, Press & Glow, Press & Clear, Pore Minimising Tonic, Blemish Control Pads, Glycolic Acid Activator) for use in a single routine - either AM or PM. For example, if you regularly use Press & Glow twice a day (as per our directions of use) and want to use Sleep Glycolic as well, we would recommend avoiding using Press & Glow in your evening routine where you are going to use Sleep Glycolic. One exfoliating acid per regime will ensure you don’t overexert your skin barrier.

Can I use AHAs, BHAs and PHAs with vitamin A?

Yes, you can combine vitamin A with an exfoliating acid. This can be a particularly effective combination for visibly improving the look of hyperpigmentation or post-blemish imperfections. However, we advise that you do not use the two ingredients in the same routine as this can cause dryness and irritation. Instead, we would recommend using either Press & Clear or Press & Glow in the morning, then vitamin A as part of your evening routine.


As we explained earlier, the overuse of high strength exfoliating acids can result in a damaged skin barrier. Of course, your skin barrier is crucial for overall skin health. Keeping this in mind, our ultimate guidance on using at-home, high strength exfoliating acid treatments is simple - treat your skin 2-3 times a week, rather than every day. Remember, it is a marathon not a sprint to reach your skin goals. Long-term skin health is the most important aim.
And with that, let us introduce Sleep Glycolic. With an innovative take on at-home, high strength glycolic acid, this hydrating leave-on treatment delivers the powerful exfoliation potential of glycolic acid in a way that keeps our skin barrier in perfect health. Recommended for use 2-3 times a week, Sleep Glycolic is crafted with Time-Release Technology which gradually delivers the 10% true glycolic acid throughout the night - minimising the potential for irritation. This is ultimate glycolic power, without the downsides.


Zooming in on our Medik8 Professional treatments, let's have a closer look at how we administer exfoliating acids in-clinic. Chemical peels are fast-becoming the number one clinical skin treatment worldwide due to their ability to go deeper into the skin, meaning they can target the most stubborn of skin concerns. Offering the ultimate in skincare results, professional peels need to be delivered in a controlled environment and are recommended for less frequent use, compared to at-home treatments. Medik8 has an extensive range of Professional Peels that are specifically formulated to target different skin concerns, such as hyperpigmentation or uneven skin tone (see Even™), or for congestion and oiliness (Clarity™ may be the one for you), or for concerns around fine lines and wrinkles (Rewind™ is our go-to peel for signs of ageing). Delivering visible results with less discomfort and downtime, we take clients on a unique peeling journey, with high performance peeling results alongside reduced sensation.
Our Peels range features an assortment of exfoliating acids; lactic acid, glycolic acid, mandelic acid, gluconolactone, pyruvic acid and lipohydroxy acid. We keep the acid concentrations high and the peel pH low for optimum penetration and results, but with the addition of irritation-reducing Time Release Technology. In each peel formulation, we have included arginine – a naturally occurring amino acid that slows down the penetration of exfoliating acids on the skin, causing the stinging sensation to build up gradually in order to ease the client into the peel experience. We never compromise on experience for results, or vice versa.

12 weeks → 8 clinic appointments → 6 professional peels

Medik8’s 12 Weeks to Wow programme introduces a form of ‘personal training’ for the skin - a 12-week programme of 6 in-clinic peels tailored to your specific concerns, combined with a prescribed at-home regime of CSA products. Clients are assigned a dedicated Medik8 professional who will guide them through their treatment journey with educational tips, personalised homecare and a unique peels experience. Over the 6 treatments, therapists have a choice of 12 peels from our portfolio to treat various skin concerns which can be built up in strength and layered for maximum results. The final appointment is the ‘WOW Reveal’ where clients will be able to measure their skin results by comparing them to photos taken in their first consultation.


At Medik8, you can be certain that we take every step to avoid any unnecessary discomfort when using exfoliating acids. When developing our exfoliating acid products in our in-house laboratory, there are many areas we take into consideration: careful selection of what exfoliating acids we want to use based on extensive research, trialling and testing different inclusion levels (%) and experimenting with different ways of delivering the acids into the skin (see Encapsulation Technology in Press & Clear and Time Release Technology in (Sleep Glycolic).
We also ensure that our ‘directions of use’ are crystal clear, and combine these amazing acid ingredients with hydrating and nourishing actives to counteract any drying or flaking. We believe that when exfoliating acids are used correctly, they are comfortable on the skin and can promote a healthy skin barrier - resulting in noticeably smooth, glowing, and resilient skin.

Medik8 Recommends

Daily Exfoliation

Press & Glow
Gentle, exfoliates skin surface only
PHAs (Gluconolactone)


Press & Clear
Clarifies, decongests and exfoliates deep within the pores
BHA (Salicylic acid)

At-Home Treatments

Use occasionaly 2-3 x a week
Sleep Glycolic
High concentration treatment. Ideal for at-home top ups.
AHAs Glycolic acid

Top tips for keeping your skin barrier healthy when using exfoliating acids:

Always check the product’s direction of use and stick to them; and be sure to give your skin a break every now and then with a barrier-building hydrating treatment.
(See Ultimate Recovery Bio-Cellulose Mask or Ultimate Recovery Moisturiser!) Following each acid use with a moisturiser can keep skin comfortable and keep the skin barrier strong
SPF is a must, in any skincare routine (see our CSA strategy).
It is especially important if you use acids, as some can leave skin more sensitive to sun damage.

Can I use a scrub with an acid? Is chemical acid exfoliation enough?

Again, we don’t want you to over do it. Keeping your skin barrier intact is crucial to skin health and over-exfoliation is not good for it. Therefore, we would always recommend to switch out your acid exfoliator on the days you wish to use a physical exfoliant.

Can I use a cleanser with acids in with a leave-on acid product (toner, serum, mask)?

Yes! Wash-off acids are fine to use in conjunction with a leave-on product, as you are not layering upon layering acids onto your skin. Providing they are washed off properly after use, they can be an excellent way to incorporate multi-acid use into your routine. Wash-off acids can be the perfect stepping stone for those hesitant to start using exfoliating acids, see Surface Radiance Cleanse for an AHA/BHA combination cleanse that quickly reveals a visibly smoother, brighter skin surface.

Of course, if you feel your skin does not react well to multi-acid use - please refrain from using both! Top tip; try them both separately first to check they are individually friendly to your skin, before using them together.