Christina Aguilera has left fans stunned with her latest TikTok video, in which she appears to have a dramatically different look.

The singer, who is known for her glamorous and often over-the-top style, has traded in her usual heavy makeup and bold outfits for a more natural look.

In the video, Aguilera is seen taking items out of her bag, while wearing an all-black ensemble and a chunky silver necklace. She has a full face of makeup, complete with a glittery smokey eye and dark red nails.

However, it didn't take long for fans to notice that Aguilera looked different than she normally does. Many commented on the video, saying that they didn't recognize her.

"No way that's Christina Aguilera," one fan commented. "Someone is pretending to be Christina Aguilera," someone else wrote.

Fans also noticed that Aguilera's signature icy blue eyes appeared to be brown in the video.

A selfie of Christina Aguilera

"Who is THAT! That is not xtina, she has blue eyes not brown! And the whole thing looks like clone but ok," one confused fan wrote. "Doesn't she have blue eyes????," another asked.

Some fans even speculated that the video was a deepfake or that Aguilera had undergone plastic surgery.

"This has gotta be AI Xtina," one TikToker commented.

However, many of Aguilera's long-time fans defended her appearance, arguing that she looks like her younger self again and is "ageing backwards."

"Omg she looks like early 2000's Xtina!!!! She looks amazing!!!" one of her "Fighters" gushed.

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"She sounds and looks like she did when she first came out. I don't understand why people say this is not her. True fans know," another user clapped back.

"If you are OG Christina fan you know this is her. She looks like she travelled back in time," one more agreed.

Aguilera has not commented on the video or the reactions to it.