Acids… just the word makes your skin bristle. Or at least conjures up images of tight, waxy faces, pink as salmon sashimi. And yet acids are now a firm part of the beauty vernacular. They’ve crept on to shop shelves and into our beauty cabinets. They’re backed by clinical trials and supported by the world’s leading dermatologists as one of the biggest skin care breakthroughs of the last century. Acids smooth lines, slough away dead skin, take the edge off sooty pigmentation marks and blitz spots. They can brighten, tighten, protect and hydrate.

“The majority [of acids] interact beautifully with the skin, which is naturally acidic, it’s just a question of finding the right one for your needs. 


Retinoic acid (Retin-A, Retinyl Palmitate, Tretinion) is what you need to ramp up collagen growth, speed up cellular turnover and fade lines. But these perks can come at a price – try dryness and redness for the first couple of weeks. So go easy there.

What to use: Retinoic acid is found only in prescription creams, but less potent over-the-counter retinoids (like retinol and retinaldehyde) are converted into retinoic acid in the body. Start with a sensitive-skin formula, such as cosmedix serum 16.

Pro tip: Apply a pea-size drop of serum 16 to your entire face. Use it every other night for two weeks, then two nights on, one night off, .Once your skin adjusts (after about a month), you can apply nightly without irritation.THE MEGA-


Hyaluronic acid (HA) is a moisture magnet that keeps skin quenched. Fatty acids, listed as linoleic, alpha-linolenic or gamma-linolenic acid, “are an integral part of our skin’s barrier,” . They shut out irritants and seal in moisture, kind of like a blanket for your face.

What to use: An AHA serum is a must for parched skin. Try (Defy)  serum from Cosmedix. Barrier-building fatty-acid creams meanwhile are soothing panaceas for everything from windburn to acid overdoses. 



Unlike water-soluble AHAs that act on the skin’s surface, BHAs, which include salicylic acid and the milder lipo hydroxy acid (LHA), are oil-soluble, so they dive deeper into the skin than AHAs, infiltrating greasy pores to root out grime. Not a job we’d fancy.

What to use: Scour the shelves for a cleanser that has 2% strength, such as  Purity Clean from Cosmedix. Washes are a better option for your skin than lotions if you’re using an intensive anti-ageing product, such as a retinoid, since it’s best not to combine two all-over leave-on products. 

Pro tip: Make an at-home DIY salicylic mask by crushing four aspirin with lemon juice. Apply the paste to the skin for 10 minutes, then wash off and moisturise.


If you want to exfoliate dull, tired skin then you need to look out for these three letters: AHA. By dissolving the glue-like bonds between skin cells, AHAs – also known as ‘fruit acids’ – basically dust off old, drab cells, ushering in a younger-looking layer. (You’ll also glow a little more, since a small amount of pigment is also shed along with the cells.) As a lovely side effect of AHAs, “when surface cells start peeling away more quickly, they signal cells deeper down to pick up production.  This includes fibroblasts, the collagen-making cells in the dermis, which keep skin firm and plump. 

What to use:  Choose an AHA wash with less than 15% buffered acid. (If you don’t see a number on the label you can assume it’s less than 10%.) Purity Clean from Cosmedix has the required amount of AHA.

Pro tip: After about four weeks of use, you can graduate to a weekly AHA peel that contains less than 10% buffered acid. Try Cosmedix Pure Enzyme Peel Mask 2-3 week. And if you want the best effects from your AHAs, always use them on dry skin. Water can actually neutralise them.


Kojic and azelaic acids interfere with melanin production in the skin’s deep layers. “Azelaic keeps pigment production in check, rather than inhibiting it altogether, as kojic does. “This is good for skin of colour, as there’s no risk of azelaic lightening the normal skin around the area you’re treating.

What to use: Look for serums that mix kojic or azelaic with other spot stoppers (hydroquinone, arbutin, mulberry, licorice) as they work best as a team. Use an AHA cleanser in the morning and the kojic or azelaic product at night to increase cell turnover.

Pro tip: Use sunscreen with zinc oxide. It shields all light wavelengths, even from computers and light bulbs, which have been shown to cause brown spots.