In The Outline, Krithika Varagur writes that “perfect skin has become the thinking woman’s quest.” She goes on to say that skin care is a consumerist scam, but she’s touched on something with her emphasis on “thinking.” Confronted with the multitudinous choices and absent good information about the efficacy of different products, many skin-care fans have become citizen scientists—educating themselves and each other about what works and experimenting on their own faces.

“For most of my life I wasn’t too serious about skin care. I’d use random drugstore products that I was drawn to on a purely superficial level,” the beauty writer Rio Viera-Newton told me in an email. “Only after college, when, for various medical reasons, I went off birth control and started having really aggressive, painful breakouts, did I decide I wanted to create a routine for myself. I was initially really overwhelmed by all the information and advice out there on the internet. I read just about every article on hormonal acne and would binge-watch ‘How I Cured My Hormonal Acne’ YouTube videos for hours.”

Viera-Newton eventually got it figured out—partly by consulting a dermatologist, and partly by narrowing down her online searches to recommendations from people who shared her dry, sensitive skin type. She built up a routine, and is now dispensing skin-care advice for The Strategist. A post she wrote in the summer of 2017, “The Google Doc I Send to People Who Ask About My Skin,” details her elaborate skin regimen. It was so widely shared that one of the autofill options when I google her name is “Rio Viera-Newton google doc.”

Framing the article as Viera-Newton’s advice to her friends was savvy. Because there are so many products out there, and because there are so many good reasons to be skeptical of brands’ claims about them, word of mouth often feels like the most trustworthy resource for information on over-the-counter skin care. People often turn to their friends—or their favorite beauty bloggers—to find out what really works. (Dermatologists, of course, are the best resource, but if you don’t have a medical reason to see one, you’re not likely to pop in and ask if you should be using Noxzema or Neutrogena face wash.)

My own skin-care routine is cobbled together with prescriptions from my dermatologist alongside recommendations from coworkers at bars, from the beauty writer Arabelle Sicardi, from the private makeup and skin-care Slack channel I share with my friends (called “People With Faces”), and from the subreddit r/SkincareAddiction.

This forum is the most visible repository of the apparently growing interest in the science of skin care. It has more than 450,000 readers, and the growth curve of its subscriber base has notably steepened since mid-2017. Its posts are a mix of memes, users seeking advice, product reviews, before-and-after skin selfies, and “shelfies”—pictures of users’ bathroom shelves crowded with products. But it also has an exceptionally well-organized reference section, summarizing the conclusions of the hive mind on ingredients, the identification and treatment of certain skin conditions, the best products, and how to build an effective routine with them. Many posts refer to scientific papers in their explanations.