When Annie Luong opened up TikTok recently, she could not escape the filter that has been dominating her feed: Bold Glamour.

"I just saw a lot of girls turning on this filter, and their reaction to the filter and how it was such an advanced filter. So I wanted to try it," said Luong, a 28-year-old who works in management consulting in Toronto.

This filter goes far beyond putting a face-altering layer over someone's image. TikTok has remained cagey about how Bold Glamour works but experts say it uses advanced artificial intelligence to remold a face into something entirely new. Noses are thinned, chins are more sculpted, cheeks are raised and eyes are brightened, as a process known as machine learning remaps people's faces.

The results have captivated legions of TikTokkers — Bold Glamour has been viewed on the platform more than 400 million times since it was released last month.

"OK, this looks pretty cool, but it just didn't feel like reality," Luong said recently, gazing at her pore-less, shimmering face recreated by Bold Glamour.

Some of the millions of TikTokkers who have interacted with the filter are speaking out against it for how uncannily persuasive it is in generating glossier, skinnier, more movie-star versions of ourselves that, unless closely inspected, can go undetected.

Unlike past social media filters, Bold Glamour does not get glitchy if your face moves in a video. When you tug on your cheeks or put a hand over your eyes, the filter shows no sign of itself.

"It is different," said Luke Hurd, an augmented reality consultant who has worked on filters for Instagram and Snapchat.

"It's not cartoon-y. It's not drastically aging you, or turning you into a child, or flipping your gender on its head," he said. "And there are a lot of times where you have to look down in a corner and see, 'is there a filter on this person?' And lately it's been yes."

Hurd said the filter is using a type of AI known as a "generative adversarial network," which is a technical way of saying it compares your face to a database of endless other faces and spits out a whole new airbrushed-looking you.

"It is simply taking images that have been fed into it and targeting parts of your face and then trying to essentially match them," he said.

That blurring between reality and fiction is something that can have a lasting impact on your sense of self, said Renee Engeln, the director of the Body and Media Lab at Northwestern University.

"Your own face that you see in the mirror suddenly looks ugly to you. It doesn't look good enough. It looks like something you need to change. It makes you more interested in plastic surgery and other procedures," Engeln said.

Engeln said a feature like Bold Glamour can pretty quickly warp a young person's understanding of what a face is supposed to look like, potentially exacerbating mental health challenges tied to self image.

"It adds to this culture where a lot of young people are feeling really alienated from themselves, really struggling to just be in the world every day with other human beings without feeling like they have to perform and appear to be someone they're not," she said. "So I think it's a good reminder that these filters should be taken seriously."

Whether generating freakishly impressive images based on simple prompts, or chatbots that can hold sometimes-disturbing conversations, new artificial intelligence tools have been capturing the minds of many. To seize the moment, TikTok and other social media companies are racing to incorporate the latest AI magic into their products.

TikTok would not comment on the design of the filter. It also would not discuss how the feature could potentially worsen peoples' image of themselves.

Instead, a TikTok spokesperson provided a statement that said the app encourages creators to be true to themselves, noting that videos on the platform mark when users create content using filters like Bold Glamour.

In Toronto, Luong said she is heartened seeing so many on TikTok, mostly young women, using the filter to talk about how social media perpetuates unattainable beauty standards.

Many who commented on her own video using the filter said they prefer the version of her without the filter.

"But then there were a few comments where it's like, 'Oh, it improves so much, you look so much better, you should always keep that filter on,'" Luong said. "That was a lot meaner. It made me feel worse about the filter."