Testing geekery...
...including how beauty products are tested (or not), my top Christmas gift for Beauty Geeks, and Daniel Sadler, make-up artist & brand founder gives his verdict on clear brow gels.
Last week I talked about product testing in relation to the amount of testing Byoma does on their products and I realised that it was becoming an essay in its own right so I decided to make a separate newsletter on it. And here it is… with slight apologies for the geekiness… but that’s what you’re here for, right? (Also I’m resolutely ignoring Christmas as I figure there are a million other people covering what to buy and that’s not what you’re here for BUT if a list of last-minute beauty buys to bag this weekend would be helpful, just shout.)
Basically, you may or may not know but, here in the UK, while there are some compulsory tests you have to do on beauty products that relate to safety and stability, not all brands will test the efficacy of a final product — I know, wild isn’t it? That means you can buy a product that says it will moisturise your skin, or improve breakouts but they might be making those claims on the basis of individual ingredients, whose claims have been provided by an ingredients manufacturer.
So, for example, an ingredients manufacturer can tell a skincare brand, “this ingredient has been shown to boost collagen production by 30%”, even if that research was carried out in a test tube, by adding the ingredient directly to fibroblasts — the cells in the skin that produce collagen — and not when applied to real live human skin. Then the brand can put that ingredient in their product — hopefully at the same concentration at which it was tested and shown to have an effect (although that’s not always a given) — and then on the packaging use tiny writing to say it “contains an ingredient that” HUGE WRITING: “boosts collagen production by 30%” without having to test the final product and so without knowing how other ingredients in the product might affect this one ingredient, or whether the ingredient actually gets to where it needs to.
It’s not that data on ingredients isn’t important, it is, but good formulators and good brands will look at (and interrogate) the claims that an ingredients manufacturer is making about an individual ingredient and then test the final product to see if they get the same results. That said, I did recently hear a horror story from a brand founder who told me that they’d got an ingredient from a manufacturer that had some quite impressive claims behind it but the manufacturer had been reluctant to share the studies behind the claims. When the brand founder eventually got their hands on the paperwork, it turned out that the ingredient had no clinical trials behind it at all, and the claims that they were making were literally based on two people in the lab trying it out and feeling that 30 minutes later their skin had improved. 😱 (My actual face when I was told that.)
I spoke to Nausheen Qureshi, a cosmetic chemist who is one of my go-tos for these sort of tech questions, about the issues around claims and substantiation.
“To make certain claims, such as anti-ageing or anti-wrinkle, you need to have completed a clinical study,” she says. “However you’re at liberty to choose whether it’s a controlled study [meaning you might test the product against a similar cream without the active ingredients] or not and whether you test it in vivo [on real people as opposed to cells] or not.” She also points out that products can be tested on just a handful of people — “and no one tells you their ages, or ethnicities, or sex — all of which play a huge factor in the efficacy of the product.”
It’s clearly a very imperfect system. So how is this legal? It’s kind of not but because in the UK claims like this are regulated by the Advertising Standards Authority (ASA) who are, let’s be honest, pretty toothless, brands are often prepared to ignore their guidance and take the risk.
The relevant guidance comes in the CAP Code (The UK Code of Non-broadcast Advertising and Direct & Promotional Marketing). It says that “marketers must hold documentary evidence to prove claims that consumers are likely to regard as objective and that are capable of objective substantiation” and “Objective claims must be backed by evidence, if relevant consisting of trials conducted on people.” Basically you have to be able to prove you’ve carried out the right tests on actual people if you’re making claims. BUT, what actually happens if you make a claim you can’t substantiate? Well first of all someone has to complain to the ASA and, if they decided to uphold the complaint they could make you pull any material that contains the claim (which admittedly might have an associated cost). Beyond that while they could refer you to Trading Standards, from what I understand this is incredibly rare, they basically rely on the fact that you’ll be publicly named and shamed and consumers might mistrust you. But have a look at the ASA Rulings over the past five or so years and you’ll see a load of names you’ll recognise — including Lyma, Silk’n, Wild deodorant and more — that haven’t exactly been ostracised by consumers…
I realise that this sounds a lot like I’m trying to tear down the beauty industry. It’s actually quite the opposite. If you’re reading this you, like me, probably know that it’s not all “just oil and water” or “smoke and mirrors” and that there’s some really good, credible science behind many of the products out there. But when brands undermine their science by making claims that are poorly substantiated, it makes the whole industry look bad. I know that conducting trials is an expensive business but frankly, if you want to make a product with any claims, I feel like you should budget for that.(I’d be interested to know what any brand founders reading this think about that.)
So what does this all mean for you as a consumer? It means that if you’re interested in a claim that a brand is making about their product, you have to ask them to substantiate it and you have to decide if it stands up to scrutiny. And I really believe that more consumers asking these questions will force brands to step things up which, in turn, means better products for you. But you can also ask people like me to hold brands to account. If you see something that looks shonky, or you want to know more about, email me (beautygeekery@substack.com) and I’ll dig into it and report back.
(By the way, if you’re interested in this sort of geekery, there’s an entire chapter on Claims Support, which talks all about the different types of test and how they’re carried out, in Ingredients (£19.65), the book I worked on with The Ordinary which, incidentally, would make an amazing Christmas present for any beauty geeks.)

While I’m still figuring out what BeautyGeekery is going to look like, I was kind of thinking that every issue should probably include a recommendation or a tried and tested of sorts, and this week, it’s… brow gels. I’m kind of obsessed, mostly because I’ve got orange bits on my brows from faded microblading so I need to cover them up, and a tinted brow gel does the work far more swiftly and effectively than any pencil that I’ve found (plus I’m lazy and time-pressed so a “two swipes and you’re done” product is the dream.) My favourite is an old one that I’ve used on and off for years — Benefit’s Gimme Brow (£14.50) — I recently rediscovered it in an old makeup bag and it was a bit like cornflakes — I’d forgotten how good it was.
Because of the aforementioned orangeness, I never really use clear ones so when makeup artist and brand founder, Daniel Sandler asked for recommendations of a clear brow gel, I sent him a load that had been hanging around in the back of my beauty cupboard and asked him to report back. If you’re in the market for a clear gel, here’s what he had to say…
Charlotte Tilbury Brow Fix, £25
Great brush, feels good to use. Once dried, the formula flakes. Didn’t like the result as it looked like dandruff.
Glossier Boy Brow, £22
Tiny brush, doesn’t grip particularly well. Gel goes on white then goes colourless , needs a lot of work to distribute white clumps of product. Did keep brows in place.
L’Oréal Brow Artist Plumper, £10.99
Brush does grip brow hairs but formula is too thin/too wet so doesn’t keep brows under control. Says it’s volumizing, but it isn’t.
BBB London Clear Brow Gloss, £23
Wand is too long. Brush is tiny but does grip hairs quite well . Formula is semi thick which is ok but to keep brows in place you’d have to wait for the first coat to dry and then layer on another coat of product.
(Just a quick note to say that all the product links in this newsletter are affiliate links. Beauty Geekery is currently a free publication and so affiliate links are a way for you to support it. As ever, I will never recommend a product that I don’t think is worth you spending your hard-earned cash on.)
That’s all for this week, more next week. Would love to know your thoughts. What do you want to see in BeautyGeekery? What burning beauty questions do you need answered? Also, if you’re enjoying BeautyGeekery and know someone else who might like it too, please spread the word.






Thank you for asking me . Hope my feedback is useful for your followers
This is brilliant Claire.. 👏👏