According to some dermatologists, high acidity is a good thing when it comes to your skin — it forms what’s called an “acid mantle” that can ward off harmful bacteria and fungi. The trouble is, short of saliva strips and liquid-based pH meters, there’s no easy way to estimate your epidermal pH.

L’Oréal is on it. At the 2019 Consumer Electronics Show, the French skincare company today unveiled a wearable and companion app dubbed My Skin Track pH — codeveloped with its skincare brand, La Roche-Posay — that can measure skin acid.

“The scientific and medical communities have long known the link between skin pH levels and common skin concerns that millions of people experience every day,” said Guive Balooch, global vice president of L’Oréal’s Technology Incubator. “Our goal is to use this advanced technology to empower consumers with meaningful information about the … condition of their skin, so that they can find the products that are right for their individual needs.”

L’Oréal says it worked with Epicore Biosystems to develop the tech, which relies on microfluidics — the study of manipulating and controlling fluids. L’Oréal claims My Skin Track pH is the first wearable to capture trace amounts of sweat from skin pores through microchannels, which it then uses to deliver a pH reading in 5 to 15 minutes.

It’s not quite as easy as, say, taking an ECG with an Apple Watch, however. Wearers first have to wait until an indicator dot changes color. Then they use the companion app to photograph said dots. A computer vision algorithm reads the pH measurement and sweat loss and delivers a report, along with La Roche-Posay product recommendations.

And ease of use isn’t the only concern, here — there’s also the question of the underlying science. L’Oréal contends that there’s more than a tenuous link between imbalanced pH levels and skin conditions like dryness and eczema, and preliminary research suggests extremely low or extremely high pH can exacerbate inflammation. A 2002 study published in the International Journal of Dermatology found that “most products recommended for sensitive skin have a considerable irritation effect, which is related to the pH of the product.”

But the strength of the link remains unclear. And according to some doctors, there’s no need to apply products that “correct” the skin’s pH levels, because the body corrects them itself.

L’Oréal says it’ll embark on a series of clinical studies in partnership with Northwestern University’s Laboratory for Bio-Integrated Electronics to investigate the connection between skin pH and conditions like acne.

But it could be years before the results of those studies complete peer review — which is probably why My Skin Track pH will initially be available only through select La Roche-Posay vendors in the U.S. L’Oréal says it plans to launch a direct-to-consumer product in the future, though one would hope not before amassing more research.