“Why settle for the ‘almost the right shade’ of blush?” Stila asks us. Its Custom Colour Blush is a “perceptive one-shade-fits-all powder (that) reacts with your skin’s pH to create a one-of-a-kind, customised shade perfect for you.” And what about Bourjois’ Rose Exclusif lipgloss? “Because the pH of your lips is unique, this lipgloss is enriched with pH reactive pigments that will self-adjust into a bespoke pink to suit your skin tone!”
This all sounds very impressive, but what’s the secret of these chameleon-like, pH-reactive products? A closer look at the ingredients list gives us a bit of a clue:
- Bourjois: Polybutene, Diisostearyl Malate, Octyldodecanol, Butyl Methoxydibenzoylmethane, Ethylhexyl Methoxycinnamate, Ethylhexyl Salicylate, Parfum (Fragrance), Propylparaben, PEG-8, Citric acid,
CI 45410 (Red 27), Tocopherol, Benzyl Alcohol, Linalool, Geraniol, Ascorbyl Palmitate, Alpha-Isomethyl Ionone, Citronellol, BHT, Ascorbic Acid 09bml0021
- Stila: Talc, zea mays (corn) starch, dimethicone, zinc stearate, zeolite, dimethiconol, sorbic acid, may contain (+/-) mica, Red 27 (CI 45410), Red 28 lake (CI 45410)
So what is Red 27?
Red 27 falls into a family of organic pigments known as non-azo soluble dyes and can change colour when exposed to different pHs. Healthy skin generally sits on the lower, acidic side of the pH scale, which helps to ward off bacteria and other bugs. When Red 27 is applied to our skin, the pigment will react to its lower pH, changing in colour and in theory producing a slightly different shade to match everyone’s own natural pH. Nice!
But does our skin’s pH really vary that much from person to person? Traditionally, picking the perfect lipstick or blush colour is down to what suits your skin tone, so for these products to transform into your perfect shade, surely the pH of skin in people from different ethnicities, and so with different skin tones, would need to vary too? Generally speaking, it doesn’t. The literature, which has been reviewed by a number of authors, shows that the pH of the stratum corneum, the outermost layer of our skin, doesn’t seem to differ significantly between different ethnicities. Therefore, these products probably won’t differ a huge amount from skin tone to skin tone, so I’m hesitant to believe any claims that the colour you’re getting is “one-of-a-kind”.
So, in summary, yes, pH is involved. That being said, I still think how these products have been marketed is a little misleading: the idea that a perfect, unique shade for our skin tone can be achieved using the “bespoke” pH of our skin just isn’t the case. While these colour-changing cosmetics are undoubtedly cool and pretty clever, I’d be hesitant to jump on the bandwagon.