Exfoliation is incredibly beneficial for a range of reasons: as you get older, dead cells can gather on the surface of your skin (due to slowing turnover), giving it dull appearance. It also helps with skin clarity, if you have scarring or breakouts, and also texture. I personally don't tend to go for physical exfoliation, as it can be harsh and often doesn't provide an even exfoliation across the skin. So, today we're talking chemical exfoliation in the form of acids, which 'unglue' these surface skin cells so they fall away and reveal radiant skin...
Toners are usually the entry level acid exfoliant, and I recommend starting at once a week but you can build up to 3 times a week if your skin likes it (as with everything: make sure you patch test before diving right in). I personally don't really recommend using them every day, morning and evening, despite the advice given out my many brands (including several I love).
Masks are a quick hit of the active because you're leaving the product on for an average of about 15 minutes. I liked masks for a long while; they worked well for me as you only really have to go in with one once a week so if you really love your retinoid and want to use that most nights, it's not as much of an inconvenience to skip it one night out of seven. On the flipside, you are exposing yourself to more potential irritation due to the strength of the product and every time my skin has been upset by an exfoliant, it has been a mask!
Cleansers are a gentle, everyday way of getting exfoliation into your routine. They're not leave-on so I wouldn't expect dramatic, 'brand new skin' results from a cleanser with glycolic or salicylic, however they can be great for daily maintenance or for those with sensitive skin.
Moisturisers are another option. I don't tend to go for them, to be honest, but I do have a couple of night creams I'll be trying soon that have some decent acid content in them. The oils and other ingredients in a moisturiser can help to buffer any harshness from the acid.
Serums are probably my preference now, and my usage can vary between once a week and three times a week depending on the formula and its strength and how my skin is feeling on the day. What I like is that you get amazing results with a serum but it's a slow-release effect, which makes it far less irritating.
I generally use acids in the evening, and apply sunscreen the following morning. You can use them in the day, potentially a milder toner or something like that. You just need to make sure you have your sunscreen on and you're reapplying it throughout the day.
- WHICH ACID? -
This is where skin type and skin concerns come in. Yes, all acids will exfoliate the skin, however they have different molecular sizes and work in different ways. I'm going to move from the more gentle options to the stronger ones (approximately)...
PHAs - this is a class of chemical exfoliant that can have some hydrating properties and are often found lower-down on the INCI list for serums, as they aid penetration of other ingredients into the skin. They have a large molecular size so work on more of a surface level, so seem to be better-tolerated by sensitive skin than some of the other options out there.
Mandelic Acid (AHA) - this is the AHA with the largest molecular size and I personally find it far gentler than something like glycolic. It has antibacterial properties to help with breakouts and there's good evidence that it's effective in treating pigmentation issues such as melasma.
Lactic Acid (AHA) - I really enjoy this milk-derived (but now often synthetically-made, for those looking for vegan skincare) AHA. There are some hydrating properties and it falls somewhere in the middle on the irritation scale. This acid can be particularly great for dry and mature skin types.
Glycolic Acid (AHA) - this is often held as the gold standard of chemical exfoliation for its ability to resurface the skin and give it an amazing glow. However, it's small molecular size can make it a little more irritating.
Salicylic Acid (BHA) - this is an oil-soluble acid that can penetrate deep into the pores to clear out debris-causing breakouts, and it can also help with the scarring left behind by acne.
- WHAT PERCENTAGE? -
This really depends on the product you're using; it's not uncommon to find a 10% mandelic acid that's still really gentle on the skin, however if that was glycolic, it would be considered pretty strong stuff! A typical concentration of glycolic or lactic would be 5%, though treatment masks can definitely get stronger and I've seen lactic acid serums at 10%. Salicylic acid can't be formulated over 2% here in the UK (and the EU) so if you're seeing higher concentrations, it might actually be willow bark extract, which isn't quite the same thing.
Not every product is going to disclose the exact percentages and some may contains blends of different acids, so the description of the product could act as a rough guide (is it called 'complete resurface' / words to that effect, or is it called 'gentle smoothing'?) However, personally I don't really feel the need any more to be using a 30% glycolic acid, when I've got some amazing formulas that give me amazing benefits without that potential risk of irritation and skin damage.
- SOME CURRENT FAVOURITES -
To round things off, let's run through some of my favourite products I've found recently and why they're so great...
Serum: Strivectin Lactic Acid Nightly Retexturising Serum* | £60 | full review coming soon | I don't use this nightly, I use it 3 times a week at most and it gives me the smoothest skin overnight, also increasing clarity over time. It gives me that immediate gratification of a good skin day the next morning.
Toner: Medik8 Press & Glow Daily Exfoliating PHA Tonic with Enzyme Activator* | £25 | full review | This is my go-to gentle option. If I'm feeling sensitive or it's during the winter and I can feel that surface dryness then this is amazing at breaking that down without being at all irritating.
Serum: Farmacy Honeymoon Glow AHA Resurfacing Night Serum | £55 | full review | This is one of the products that really got me into lactic acid: it gives me incredible results in terms of smoothness with no dryness and no irritation. I'd say this is an intermediate formula.
Cleanser: Skingredients Sally Cleanse | £25 | full review | I generally have quite dry skin but I do get hormonal breakouts. This is a really gentle way to clear that congestion. The brand even says to leave it on for a couple of minutes to really allow it to work and this helps my breakouts without drying out my skin as a whole.
Mask: Algenist Blue Algae Vitamin C Dark Spot Correcting Peel* | £80 | full review | This is pretty pricey but it's packed full of incredible ingredients, including glycolic acid, ascorbic acid (the OG Vitamin C), salicylic acid, mandelic acid and tranexamic acid, buffered with glycerin so it's incredibly gentle whilst giving amazing results.
Toner: Glow Recipe Watermelon Glow PHA + BHA Pore-Tight Toner | £31 | full review | This is that rare hydrating exfoliating toner and the blend of PHAs and BHAs means it exfoliates on the surface and deep within the pores.
Serum: PSA Liquid Clarity BHA & Bakuchiol Blemish Recovery Booster* | £27 | full review | This is a lovely hydrating serum that contains a blend of willow bark and salicylic acid that helps to clarify and decongest the skin without being too harsh or drying. Sidenote: I do also love their exfoliating toner (not pictured as I'm in-between bottles, but I reviewed it here).
Serum: Kora Organics Noni Night AHA Resurfacing Serum* | £65 | full review | This is pretty similar to the Farmacy formula, to be honest. It's a gentle, moisturising option for incredibly smooth skin and an instant glow-boost. This one is formulated with lactic acid.
Oil: Sunday Riley UFO Ultra-Clarifying Face Oil* | £68 | full review | Salicylic Acid is the oil-soluble exfoliating acid, so that's why it can come in this form! This product combines the spot-fighting benefits of the ingredient with a moisturising base, making it perfect for my dry skin when I'm breaking out. This is amazing for me at clearing up any congestion and the oil formula means it's very gentle.
What's your favourite acid and how do you like to get it into your skin?