After Dillon Latham’s girlfriend dumped him during their junior year of high school, the then-17-year-old decided to invest in his appearance. He began spending hours daily in the gym, applying homemade skincare concoctions to his face like beef tallow moisturizer, and permed his hair to give it a tousled mop look. He says he felt and looked better.

Soon, Latham started posting tips on TikTok to inspire teen boys in similar situations. His videos are captioned with language like “this is making you ugly,” “stop ruining your skin,” and “get a smaller nose.” The makeover advice went, and continues to go, viral. To date, his TikTok clips have nearly 98 million likes and 1 billion views across social media. Latham, who is now selling his own brand of hairspray, says he’s making six-figures in revenue monthly from sales and social media, leading him to skip college and be a full-time influencer.

Latham’s videos are part of a trend called “looksmaxxing” that capitalizes on mostly boys’ insecurities, and tells them they can become attractive and masculine by toning their faces and bodies via rigid fitness, skincare, and hair care routines. In its mildest form, looksmax social media creators tell teen boys to wash their faces; in its most extreme, they tell boys to regularly pummel their jaws to induce micro fractures, get surgery, and take steroids. Social media algorithms tend to amplify this content.

Psychologists interviewed by Fortune expressed concern about the trend. They assailed the potentially devastating effects of the online advice and criticism that makes those seeking it feel inadequate and unattractive.

“Psychologically, it’s essentially an erosion of the sense of self,” says Tom Hildebrandt, a clinical psychologist who has studied eating disorders for 20 years as the chief and founder of the Hildebrandt Laboratory at the Icahn School of Medicine at Mount Sinai, in New York City. “It’s like, ‘The more I get feedback that I’m not good enough, the more I consume it. And then, I trade my attention, my time and sometimes my money and resources to give up my current identity in pursuit of this other one.’”

Latham, too, says the negative content he posts attracts far more views and engagement than positive stuff. So the now 19-year-old continues to insult the appearances of his viewers, and in turn, sell more products, mostly via TikTok Shop.

He dismisses the critics, saying they should listen more closely to his advice. The negativity in his videos is mixed with positive messages, he argues. “People are really attracted to negative things because so many guys are insecure—so you pull them in with that in a way, and then try to help them.”

This negative feedback loop has also spurred a burgeoning looksmaxxing economy, including chewing gum meant to help with jaw exercises, personal care products, and clothing.

Meanwhile, a number of apps claim to evaluate the looks of users and their success in following the looksmaxxing message. The most popular app is UMAX – Become Hot. Powered partly by OpenAI’s technology, UMAX rates paying users’ faces on masculinity, their jawlines, and cheekbones, among other attributes. Though it launched in December, the app is already raking in about $500,000 in subscription revenue monthly, according to Blake Anderson, the app’s 23-year-old founder and CEO. The amount could not be independently verified.

UMAX, which relies on users uploading headshot photos, costs $3.99 weekly. It scores users’ faces each week on a scale up to 100, and gives tips like “start a skincare routine” to increase their scores. Though the app says users can forgo the first weekly fee if they refer three friends, this feature didn’t work in Fortune’s test of the app.

UMAX has over 7 million total downloads, according to Anderson, and climbed to number 36 in the Apple App Store’s Lifestyle chart, which ranks apps by downloads, app usage and velocity of downloads. It ranked higher than the apps of Zillow Rentals and handyman service TaskRabbit. Anderson says 90% of users are males aged 16 to 45.

He credits UMAX’s popularity to its social media presence, helped by users who often show screenshots of UMAX’s app as a backdrop in their own social media videos in which they discuss their looksmaxxing journeys. He says UMAX has garnered over 1 billion impressions across all social media platforms. A UMAX competitor, LooksMax AI – Face Style Rater, is also among the top 100 lifestyle apps. (Its developer did not respond to Fortune’s interview request.)

“Social media, as a whole, is the greatest advertising channel to exist,” says Anderson, who wants to build a brand that “embodies male self improvement.” “The videos that tend to do really well are glow up videos: ‘This is me before—maybe I had acne or wasn’t as good looking, wasn’t taking care of myself—and now, this is me after.’ UMAX scores help to quantify that change.’”

In response to critics who say that UMAX may contribute to users’ negative self-perception, Anderson says: “We never want somebody to feel insecure to the point that it causes anxiety or significantly impacts their mental health…If we just tell everyone to just love who you are 100% and there’s never anything that needs any work—I think that’s a dangerous mindset…self-improvement is extremely important and pays dividends over the course of one’s life.”

Another reason for the growth of the looksmaxxing economy is TikTok Shop.

Looksmax influencer Latham calls it an “insanely profitable” platform for his haircare brand because “you can literally just buy a product on the same screen that you watch the video.” He says the success of his brand on TikTok Shop is a reason he decided to forgo college to focus on his social media creator career.

TikTok did not respond to Fortune’s request for comment.

Mount Sinai’s Hildebrandt is deeply worried about the potentially devastating effects of negative content delivered through an algorithm, as he believes this could cause widespread and often-undetected male body dysmorphia. This phenomenon, he says, gained traction during Arnold Schwarzenegger’s muscular rise to fame in the 1980s. With the rise of social media, the problem has been supercharged and harder to detect. Now, the disorder is often characterized by people spending excessive time consuming and thinking about online beauty and wellness content. On the surface, it’s largely indistinguishable from today’s norm of people scrolling on their phones for hours on end.

Hildebrandt is unsurprised that UMAX’s app and Latham’s hair care products have caught on. He believes the looksmaxxing economy takes advantage of men’s insecurities using methods that have minted female-focused cosmetics and wellness brands trillions of dollars. “The producers of [looksmaxxing] content and products are figuring out that men are just as vulnerable as women to that negative feedback…if you make anyone feel insecure about their identities, they are willing to throw money after a solution for that.”

TikTok has cracked down on weight loss content, though psychologists say problematic content very much still exists. A search for “looksmax” on the platform returns a banner saying “you are more than your weight.” The message is accompanied by a cartoon character hugging a heart and an option to click on a message that says: “If you or someone you know has questions about body image, food, or exercise — it is important to know that help is out there and you are not alone.” Users can follow links to TikTok’s own eating disorder resource center and nationaleatingdisorders.org. But once users begin to scroll, the banner disappears.

Meta-owned Instagram and Facebook, Google’s YouTube, and Snapchat have no such warnings on looksmaxxing content.

Instagram, which CNN and Sen. Richard Blumenthal (D-Conn.) said in 2021 promoted eating disorder content to teens, has a page about eating disorders that focuses on how users should approach friends about the problem. Facebook has a similar page. A Meta spokesperson declined to comment for this story, but pointed Fortune to its policy on suicide, self-injury and eating disorders.

Though the company says it removes “any content that encourages suicide, self-injury or eating disorders,” it allows “people to discuss these topics because we want our services to be a space where people can share their experiences, raise awareness about these issues, and seek support from one another.”

Meta says that it has added popup on searches related to suicide, self-harm, eating disorders or body image issues that gives users tips and ways to connect with relevant organizations, but it has no such warning on looksmax-related searches. When Fortune searched for “looksmax” on Instagram, it found a video of a user with a chiseled jaw who claimed to have obtained it by hitting his face with a hammer (a practice known as “bone smashing”). The video shows users how to do it, while warning of its dangers.

Snapchat provides users with no information about eating disorders. A spokesperson for the platform declined to comment for this article, directing Fortune to its guidelines about the kinds of posts its algorithm recommends, noting the company prohibits the promotion of self-injury, suicide and disordered eating content. Despite the rules, under the #looksmax hashtag on Snapchat, Fortune found a number of posts that promote self-harm and violence. One video that begins with a selfie video of looksmaxxer is captioned “when she says I’m going to party with my new friends,” followed by a sequence of people firing assault rifles. A caption on the clip then said “me after pulling up to that party.”

In response to looksmaxxing content on YouTube, a spokesperson for the platform told Fortune: “YouTube has extra safeguards in place for videos recommended to teens and younger viewers, developed in consultation with child development experts.” The spokesperson, who share a link to the safeguards, says the company “limits repeated recommendations of content that compares physical features and idealizes specific fitness levels or body weights over others,” noting it has policies to remove content about disordered eating behaviors that “can be easily imitated.”

Social media companies are already facing scrutiny from federal and state officials for allegedly causing a youth mental health crisis with their addictive algorithms and features. A key accusation in these lawsuits and initiatives is that social media platforms incite body dysmorphia in users, especially young females.

But looksmaxxing may be evidence that young male users are just as affected by body dysmorphia.

Sera Levelle, a clinical psychologist who treats eating disorders and disordered eating in New York City, says she now has an even split of male and female patients. When she started her practice in 2007, it was mostly women and girls. Levelle says that over the last 10 years—concurrent with the rise of social media—the gender makeup of her patients has reached parity. “Society is now getting equally horrible for men as it has been for women for a long time,” says Levelle.

Levelle’s anecdote is consistent with national reports that show that diagnosed male eating disorders have increased with social media’s rise.

Sarah Davis, also a psychologist in New York who is focused on children’s eating disorders, notes that a few patients have engaged in a looksmaxxing exercise during therapy sessions called mewing, a belief that touching one’s tongue to top of mouth through clenched teeth can spur a defined jawline. She blames social media as her patients get “younger and younger,” with the youngest being nine years old.

“We all want to be loved and accepted,” says Davis. “People think, ‘If I look a certain way, and I can throw money at that [to be loved and accepted,] then I’ll do it.”