Women's Health - UK (2019-07)

boost hyaluronic acid (more on which

later) in the lower skin layers, plumping

fine lines and wrinkles,’ says Paula Begoun,

dermatologist and founder of skincare

brand Paula’s Choice. Glycolic acid is so

ruthlessly efficient that it only takes one

application to yield results. The downside?

It works so quickly that skin can become

irritated. This is where percentages come

in – the higher the strength, the more likely

irritation will occur. If you’re a glycolic

virgin, start with formulations between

3% and 5%. ‘These will hit the sweet spot

for daily use, because any irritation will

be very minimal and will subside after

a few applications,’ says Isaacs. ‘You’ll

know, because the tingling sensation will

disappear. However, be sure to give your

skin regular breaks. So, use one bottle of

product, then have a month off.’ Once your

tolerance rises, you can move on to stronger

formulas, around 10%. Anything higher

should be used as a one-off treatment.

It’s not just percentages that are key, pH

levels are equally important. Some brands

will formulate their glycolic acid with a high

pH level to counteract potential irritation,

but this also weakens the acid. (The higher

the pH, the more alkaline something is; the

lower, the more acidic it is.) ‘If you have a

product with 5% glycolic acid, but a high

pH level, it weakens the acid, lowering it to

around 2%. The ideal pH level for glycolic

should be three to four. This means the acid

percentage stated on the label will be true to

form. ‘pH levels aren’t always stated on the

label, so check the website,’ suggests Isaacs.

Lactic acid

Best for: Dry skin

Remember the tale of Cleopatra bathing in

milk? Well, she was way ahead of the game,

because sour milk produces lactic acid. Now

created synthetically in a lab, this AHA is

gaining a following because its molecules

are bigger than those in glycolic, so don’t

penetrate as deeply to trigger that peeling

action. If you have dry or sensitive skin, this

is a good thing. ‘At low percentages, around

5%, lactic acid also acts as a humectant,

drawing moisture into the skin while it

exfoliates,’ says facialist Kate Kerr. It won’t

provide dramatic overnight results on its

own, so if you have a party, job interview or

date for which you want instant results, opt

for a formula that combines lactic with

glycolic acid and plenty of antioxidants. This will still

be weak enough not to cause irritation, but strong

enough that you’ll notice a difference come morning.

In Sunday Riley Good Genes, £85, lactic and glycolic

are combined with squalane to retexturise and hydrate.

Mandelic acid

Best for: Pigmentation and acne

This is the newest AHA on the block. Research

published in Dermatologic Surgery showed that it was

as effective as glycolic at treating pigmentation from sun

damage, but with less redness and irritation. And further

studies show that it also reduces melasma by as much

as 50% in four weeks. Mandelic’s molecules are twice

the size of glycolic’s and a third bigger than lactic’s, so

irritation is reduced, as it takes a long time to penetrate

the skin. But don’t be fooled by its softly-softly approach.

Like other AHAs, mandelic’s micro-exfoliating properties

help lift excess pigment from the skin’s surface. However,

it’s the only AHA to work in the skin’s deeper layers to

inhibit melanin production. So what it might lack in

speed, it makes up for in depth. Its gentle approach

also makes it a winner for those with darker skin tones,

who should avoid glycolic and lactic acids because the

irritation they cause can lead to post-inflammatory

hyperpigmentation. ‘This is because there’s more

melanin in the skin, which means there are also more

melanocytes to react to irritation and trigger excess

pigmentation,’ says Dija Ayodele, facial aesthetician

and founder of the Black Skin Directory. If that wasn’t

enough, it’s also being championed by cystic acne

sufferers who are preaching its benefits on internet

forums. ‘As well as exfoliating, it also has antibacterial

properties, which help to regulate sebum production,’

says Dr Wei Chen, senior research and development

manager at Dermatologic Cosmetic Laboratories. This

stops acne forming. Products with 5% mandelic acid will

be gentle enough for everyday use. ‘If the formulation

contains 10% mandelic acid, it should be applied two or

three times a week, always in the evening,’ says Shabir

Daya, co-founder of victoriahealth.com. That’s because

AHAs increase your skin’s sensitivity, so you’ll also need

to boost your UV protection with a good SPF.

Fears around AHAs aren’t totally misplaced. ‘I’ve seen

a rise in patients coming to me with concerns about

irritation from overusing or misusing acids,’ says Dr

Sarah Shah, founder of the Artistry Clinic. Her advice? If

you haven’t used acids before, start by working one into

your routine with a wash.’ Something like Peter Thomas

Roth 3% Glycolic Solutions Cleanser, £36.60. ‘This

limits the amount of contact time with your skin and

avoids over-drying.’ Then you can move on to a serum

or peel pads. Just make sure you’re only using one acid-

based product in your regime. ‘You also don’t need to

start on a single acid first [products containing a mix of

acids are fine], but it’s beneficial to help you understand

which ones work best on your skin,’ adds Isaacs.

JULY 2019 | 89

‘Acids are extremely effective and

their effects can be seen very quickly’

B E A U T Y

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