The Rise of Ingredient Anxiety—Why Our Obsession With Scanning Beauty Products Is Becoming Toxic

“I used to love this,” says the woman standing next to me in Boots. With a wistful sigh, she places the bottle of serum back on the shelf. The only thing standing between her and her favourite Elemis Pro Collagen Renewal Serum isn’t the £78 price tag but a carrot. “It only scored 33 on Yuka,” she whispers, by way of explanation.

Beauty scanning apps that determine the toxicity of your skin and hair care are booming. Arguably, the most famous of these is the Yuka App with its distinctive vegetable logo, which an estimated 5 million people in the UK now consult for cosmetics and food purchases.

According to the brand’s website, what happens behind the scenes goes a little like this: Scanning a beauty product’s bar code with your phone pulls up its ingredients. The Yuka App then assigns a risk level to each one based on the potential effects to your health and the environment—for example, if it’s an allergen or carcinogen. It does so via an algorithm that’s managed by Yuka’s team, which includes a toxicologist, and takes into consideration data from bodies such as the European Chemicals Agency.

The database includes around 12,500 cosmetic ingredients, but the final safety score out of 100 is based on how much of the highest-risk ingredient is present in the product. A score of 75 to 100 earns a dark green risk-free dot; 50 to 74, a light green “good”; 25 to 49, an orange “poor”; and 0 to 24, a red “bad”, indicating the presence of potentially harmful ingredients.

The Pros and Cons of Product-Scanning Apps

But product-scanning apps such as Yuka, Think Dirty and INCI Beauty are dividing the experts. Skincare founder Irene Forte says the apps are empowering beauty shoppers to make more informed choices, especially those who know what ingredients they’re keen to avoid. “I like that they tell you in a snapshot what’s actually in a product—something that’s often hard to read on the pack,” she says.

However, some cosmetic chemists and skincare experts say it’s not that straightforward. For starters, there’s the ingredients list itself. By law, beauty brands are only required to list ingredients in descending order based on weight. So an app can’t know exactly how much of an ingredient is actually in a product. “Scanning apps assess ingredients in isolation without knowing the percentage, the delivery mechanism, or the overall formulation,” explains Daniel Isaacs, a chemist and the director of research at Medik8. “In science, the dose makes the poison. Even pure water can be harmful in excess, whereas potent actives like retinaldehyde are exceptionally effective and completely safe when delivered at precise, controlled levels.” Ginger King, an award-winning cosmetic chemist who has formulated hundreds of products for brands including Joico and Avon, echoes these frustrations. “In a cosmetic formulation, consumers aren’t likely to use one ingredient by itself at 100%,” she says.

The worry is that this methodology can demonise some ingredients unnecessarily. One example is phenoxyethanol. “At 1% it’s a perfectly safe and good preservative,” says King, a claim that’s backed by the European Commission. Yet Yuka assigns phenoxyethanol a damning orange dot. Similarly, when Dr Ash Soni, a plastic surgeon and founder of The Soni Clinic, used the Yuka App to test some of the skincare in his clinic, the inclusion of phenoxyethanol at an extremely low, legal concentration skewed the results and rated the overall product as “poor”. “I know how well formulated these science-backed brands are, and the research behind them,” he says. “A tiny dose of this preservative would never cause any type of irritation or harm to your skin. But it’s needed to stabilise a product and prevent the growth of harmful bacteria and mould.”

From my own research, I also found that results varied from app to app, which muddies the waters. When I scanned the products I’m currently using on the Yuka App, my Skinceuticals P-Tiox cream scored highly with 86/100 and my tinted La Roche-Posay Anthelios UVAir Serum Sunscreen SFP50+ a solid “good” 57/100. My CeraVe Foaming Cleanser, however, only scored a “poor” 39, prompting the app to suggest Simple’s Kind To Skin Moisturising Facial Wash as an alternative. But when I put the same products through the INCI Beauty app, the cleanser scored a light green 11.8/20, literally giving me the green light to use it. The sunscreen sat unfavourably between the orange and low yellow colour bands with a score of 8.9/20 and, while still good, the P-Tiox cream was only rated 11.4/20.

So Should We Use Product-Scanning Apps Like Yuka?

All that said, you can’t ignore the impact of product-scanning apps on the beauty industry. “I love seeing how passionate people have become about what goes onto their skin,” says Isaacs. “The popularity of apps like Yuka shows that consumers want transparency and want to understand their products. These apps have helped to demystify skincare jargon and encouraged people to look beyond marketing claims. They have put healthy pressure on the beauty industry to be more open.”

A number of beauty brands are also betting on Yuka validations. Forte notes that “excellent” ratings on Yuka for products such as the Almond Cleansing Milk, which scored 100/100, and the new Red Algae Resurfacing Body Exfoliator drive revenue and brand loyalty for her brand. “We made the scores visible on our product pages and, since introducing them, our conversion rate increased by 88%,” she explains. “Independent retailers are also taking us on, partly because of our Yuka rating. And more and more customers are scanning in-store and shopping with us because of our scores. Ultimately, with tens of millions of users, it’s become a very powerful app.”

There’s no denying, too, that they reflect a cultural shift towards self-empowerment by beauty fans. One of Forte’s favourite features on the Yuka App is that it highlights fragrance allergens, especially essential oils. “In the US, brands still aren’t required to disclose fragrance allergens on pack, and in the EU/UK they can note “from organic sources” with an asterisk without stating it’s an allergen. I find that misleading, and I love Yuka for calling it out—especially because people with sensitive skin often assume natural means better.”

But the debate still rages about the accuracy of these apps. While Forte acknowledges that not knowing the exact percentage of each ingredient is a shortcoming, “Yuka still highlights everything a product contains,” she says. “Even at a low percentage, it’s there—a 100/100 score means there’s no debatable ingredient in the formula at all.”

Dr Soni takes a more cautious view. For him, the biggest issue is that these apps oversimplify toxicology in ways that can mislead shoppers. “There’s a lot of science and data behind skincare products,” he explains. “Apps like Yuka are creating a traffic light system to simplify things that are actually quite complex. But they’re not always taking into account the true science and data from that brand—they’re pulling ingredient data from lots of different sources and we don't actually know what these clinical studies are.” For this reason, he cautions against chucking a product just because it scores low on an app. “If you’re using skincare by a reputable brand, you like it and your skin is tolerating it well, then I don’t see a reason to throw it away,” Dr Soni says. If in doubt, his advice is to speak to a professional—either your GP, a dermatologist or an aesthetic doctor.

Meanwhile, Isaacs recommends taking automated risk scores with a pinch of salt. “From a formulation and research perspective, I would recommend viewing these risk scores with caution,” he says. “The fundamental issue is that safety cannot be reduced to a simple red-or-green score based on an ingredient list alone. It tells you what's in the bottle, but it tells you nothing about the concentration, the purity of the raw materials, the pH, or how the ingredients interact within the total formula. When you strip away the toxicology context, you replace genuine science with unnecessary alarmism.”

It’s also worth noting that in the UK and EU, beauty brands operate under some of the most stringent cosmetic safety laws in the world, Isaacs adds. Taking his own brand as an example, he says, “Every Medik8 product undergoes rigorous clinical testing and complies with the strictest safety standards. Before it reaches a customer, it is evaluated by a qualified independent toxicologist who looks at every single detail. Apps often flag safe, approved, and heavily tested ingredients as dangerous, which distorts the real science. We need to trust the true experts here—cosmetic toxicologists.”

Still, technology moves at a speed of knots, so perhaps there’ll be a scanning sweet spot that satisfies both supporters and sceptics in the not-too-distant future.