By Claire Coleman


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”.


The episode originally aired in 2002 and really reflected the fact that, back then, most people who encountered acids from a skincare perspective did so in clinics or doctor’s offices. And, by acids, in this feature, we’re really talking predominantly about AHAs — although BHA- and PHA-based products do get a brief look-in too.


“At first, acids were definitely not a retail ingredient,” says dermatologist Dr Dennis Gross, who launched his skincare line at almost exactly the same time that Samantha was showcasing the results of her peel. “They were used by derms and, occasionally, plastic surgeons, as in-office procedures. We used TCA (trichloroacetic acid) and phenol (carbolic acid), but they were very harsh and quite radical in terms of downtime (ie You looked bright red and had to hide yourself away for days if not weeks). There were also the risks of scarring and, while the results were good, they were not something I thought was great.”


That said, while most consumers would only ever encounter acids in a professional setting, since the 1970s, there was one cult product that, in certain circles, had become legendary and could well lay claim to being the first ever acid skincare product for home use. That product was Biologique Recherche’s P50.


P50 was created by French biologist, Yvan Allouche, for his wife, Josette. The original formulation used phenol and was intended to gently exfoliate the skin. Dr Philippe Allouche, Yvan and Josette’s son, who is one of the co-owners of the brand, told Refinery 29 that his parents began sharing the product with their friends in France and abroad, before launching it to the press in the late 1970s.


While the original is still available in some parts of the world, it’s now known as P50 1970, and you won’t find it in the EU or Canada where phenol is not allowed to be used in cosmetic formulations. Instead, you will find four other versions, including P50, the most powerful and the closest to the 1970 version but without the phenol; P50W, for sensitive skins; P50V for older skins and P50 PIGM 400 for pigmented skins. All of them contain lactic acid, malic acid, citric acid, salicylic acid and gluconolactone: a combination of AHA, BHA and PHA exfoliants.


Part of the mystique of the legend of P50 was that you couldn’t just pick it up off the shelf, you had to see a professional — a facialist or aesthetician — and buy it from them. (You can now buy it online but it’s not as easy as click and go, you have to sign up and take a skin analysis, etc). So, while there’s no doubt that P50 was the brand that first put acids in the hands of consumers for home use, it doesn’t really count as the first commercially available acid skincare.
That honour goes to Avon who, in 1992, became the first beauty company to bring alpha hydroxy acid technology to the mass market, with the launch of the ANEW skincare line and the Perfecting Complex for Face, which contained glycolic acid.


“Having uncovered the benefits of AHAs, we immediately partnered with the scientists who discovered them to bring them to the masses with our award-winning brand: ANEW”, says Anthony Gonzalez, current head of skincare R&D at Avon. “This was a pivotal moment in skincare history”.


 ANEW remains Avon’s biggest skincare brand and, when it comes to glycolic, they’re still innovating. They claim their new Revival Serum Lipstick is an industry-first, combining colour payoff with efficacious skincare ingredients, including AHAs, to help treat not just the symptom but the cause of dry lips.
Other big brands followed Avon’s lead and, by the mid 1990s, AHA-based products from Estée Lauder, Prescriptives, Elizabeth Arden, Decléor, Murad and many more were popping up in our bathrooms. But, for Dr Dennis Gross, the issue was that these were all one-step treatments that echoed the approach that was still being taken with peels in doctors’ offices.


“I set out to create an AHA peel with no downtime. For me the ‘Aha!’ moment [he doesn’t say ‘pun intended’ but I totally think it was] was when I realised that you have to neutralise the acids to stop them working, and that second step is the key to making it effective, but gentle”.


He started out by working with a blend of acids that he used in a professional treatment before thinking about formulating it for home use.


“I had a client take home two canisters of pads. There was acid in one and neutraliser in the other, and they were designed to be used two minutes apart. The first step exfoliates, removing the top layer of dead skin and bringing the younger epidermal cells to the surface, but that’s the least of it. Like all tissues in the body, those fresher, younger cells are more avid to take up nutrients, so that’s when the second step does more than just neutralise the acid. It also includes anti-ageing ingredients, antioxidants, vitamins, soothing ingredients”.

And so the two-step peel pads were born. They’ve recruited an army of followers, including Naomi Campbell and Rosie Huntington-Whiteley — and apparently a pack now sells somewhere in the world once every three seconds.
While pads continue to be a staple in many skincare routines, a smart bit of marketing saw acids in skincare reborn as the modern form of toners. The original toners of the cleanse, tone, moisturise routine have become somewhat anachronistic, as dermatologist Dr Zoe Draelos explained in a piece for Dermatology Times.


“Toners were originally developed to remove soap scum from the face when lye-based soaps, combined with hard water, left a sticky residue post-cleansing. The alcohol-based toner removed the soap scum, eliminating irritation and contributing to cleanser mildness”.


These days, as our cleansers are decidedly more sophisticated than lye-based soaps, they’re not necessary, but that stage in the routine is the perfect place to slip in an acid. Add to that the fact that, over the last ten years, dermatologists have increasingly warned against the use of physical exfoliants — anyone remember that apricot scrub that genuinely scoured the skin? — and encouraged the use of chemical exfoliants, aka acids, that do a similar job, just in a more uniform and gentle way. It’s easy to see how acid toners became “a thing”.


One of the brands at the vanguard was Pixi Beauty, whose Glow Tonic sold out in 2012 after Caroline Hirons raved about it on her blog. Other brands have since developed their own, with Medik8, Ren and The Ordinary among many brands giving you the option to swipe a glycolic-soaked cotton pad across your skin post-cleanse.


So what’s the future for acids in skincare? Perhaps understandably given that the concept is his baby, Dr Gross feels that consumers haven’t yet got the message that two steps are better than one and that more education is needed here. But, more broadly, he is also wary of the trend for plastering percentages on labels, which seems to result in a race for brands to outdo each other with ever higher percentages of acids.


“It’s gamesmanship — fundamentally there are laws that govern what concentrations are included in over-the-counter products,” he says. “And, when it comes to acids, more isn’t necessarily better. More can cause damage”.
He also points out that without knowing the details of a formulation or its mechanism of action, the numbers are meaningless.


“You might claim a very high concentration of acid on your label, but the formulation might mean that that’s not the effective concentration”.
However, he also believes that consumers are: “smarter than ever, they’re doing their research, looking to learn, and not being spoon-fed commercialism and marketing jargon”. And, as he puts it, “truth prevails, honesty prevails and results prevail” — which is why there will probably always be room in your regime for a well-formulated, effective acid product.