You've probably heard a lot about acids in skincare. They sound a bit scary, but also excitingly powerful - what exactly do they do, and do you need to use them? Here's the lowdown on the most common acids in skincare. 

Hearing the word ‘acid’ in conjunction with a skincare routine may sound counter-intuitive, but acids can be excellent for your skin and should be a part of a solid routine. With countless acid products and even more misinformation coming from websites, celebrities and, in some cases, brands themselves, it can be a minefield to get your head around. It doesn’t need to be. The trick to choosing the best acid for you is to focus on the skin concern you want to address. Yes, it really is that easy.  Before we deep dive, it's helpful to understand the different types of acids that are out there:  Beta Hydroxy Acid – BHA (There is only one BHA, which is salicylic acid): Best for breakouts or acne Alpha Hydroxy Acids – AHA: Best for signs of ageing Polyhydroxy Acid – PHA: Best for those with sensitive skin, who want the results without the potential for irritation. Salicylic acid is best for those with blemishes and breakouts. It can usually be found at 0.2% in OTC products. It will be used in higher concentrations for a professional face peel to treat acne, acne scars, melasma, sun damage and age spots, but a hard core treatment like this should only ever be done under the advice and supervision of a trained medical professional. Glycolic acid (AHA) is best for those who are concerned about signs of ageing. It is the smallest AHA and is effective at getting into the skin to reduce fine lines. It also helps prevent acne, fade dark spots and even skin tone and texture. Glycolic acid does increase sun sensitivity, so it is vital to use an SPF while using glycolic acid to prevent any sun damage. Lactic acid (AHA) is your go-to if your concerns are dull, dehydrated or dry skin. It has a larger molecule than glycolic, so is gentler on the skin but still does a great job exfoliating the skin in a more sensitive fashion. Mandelic acid (AHA) is similar to glycolic acid and can be used to prevent acne and even pigmentation. It’s also a great option for oilier skin. Due to its larger molecular structure, it doesn’t penetrate skin as deeply as glycolic acid, making it less irritating. Don’t be fooled though; mandelic acid can penetrate the greasiest skin, and with regular use can reduce oiliness without drying out skin. Gluconolactone Acid (PHA) is your go-to if you have sensitive skin. Gluconolactone is mostly an antioxidant which attacks free radicals, protecting the skin from sun damage and strengthening barrier function. Over time, gluconolactone can reduce redness and it also helps maintain elasticity in the skin. Lactobionic Acid (PHA) is best suited to skin that is dehydrated. It may help prevent and reverse signs of ageingsuch as lines, pigmentation, large pores and uneven skin texture.

If you’re a woman of a certain age, then your introduction to acids in skincare was probably that infamous episode of Sex And The City when Samantha Jones tries a “freshening chemical peel” and ends up with a raw, red face that genuinely frightens children and causes Carrie to compare the results to “beef carpaccio”.

Beauty trends are ever evolving, especially within skincare. New technology breakthroughs, ingredient discoveries and delivery systems are constantly advancing. So, when a product has been around for a long time, it generally means it is something unique and special that can stand the test of time.