Welcome to the 'undetectable era' of cosmetic surgery.

If it feels like you've walked into some weird time warp, where all your favourite celebrities look the same as they did 20 years ago but… better, please take a seat.

It's not just you.

Let's start with that video of Christina Aguilera that went viral recently — and for good reason. The singer, who was dressed in Cosplay for a performance in Osaka, showed off a high, slicked-back ponytail and perfectly flawless makeup. At 43, she didn't just look "good for her age". She looked… impossibly younger.

Watch: We asked a cosmetic physician everything she'd do to our face. Post continues below.

And the speculation in the comment section BLEW UP. Is it real? Is it AI? Some kind of DNA cosmetic procedure? The salmon sperm! Must be the salmon sperm.

One comment read: "What year is it."

Another said, "Wait what am I back in 2002."

"Okay so are we in a time capsule?" wrote someone else.

People wanted to know if she'd been on Ozempic, what she did to her face, but most importantly — who her surgeon was and just how they did it.

Because while the relationship between celebrities and cosmetic surgery is not news, this is. Because the impossibility of her ageing process makes it feel very different. It's not just injectables or a face lift — it's a full physical aesthetic transformation.

Image: Instagram/@xtina.

Then there's Lindsay Lohan.

After recently attending New York Fashion Week, the actress garnered a wave of attention for her appearance. She looked stunning. And fans couldn't help but be curious about what procedures she's had to look this good.

On Reddit, fans speculated what kind of cosmetic treatments she'd undergone, with one comment ringing true: "She ... looks really good. Whatever she did, it was done tastefully."

Image: Instagram/@lindsaylohan.

And what about Matt Damon? If you recently spotted him on Toronto International Film Festival red carpet, you would've noticed just how… fresh he looks. With a smooth-looking forehead and minimal lines, the actor looked like a youthful, rejuvenated version of himself. But nowhere near 52.

There's also other celebrities like Christie Brinkley and Gisele Bundchen — youthful, refreshed faces that make it tricky to pinpoint what's actually changed. Scroll through these celebrities Instagram feeds and you'll read comments like: "the surgeon deserves a Nobel Peace Prize."

And according to surgeons, there's a good reason celebrity faces look different. Apparently, we're in the midst of what's been dubbed an 'undetectable era', where the telltale signs of cosmetic surgery are almost blurred. While we're used to spotting overfilled lips, frozen faces and that very recognisable 'done' look, these days cosmetic work is almost devoid of the signs we're so used to seeing — but that's the goal, right?

Whether you want to thank the revolution of weight loss drugs or the cutting-edge procedures and advancements in the aesthetics industry (using your own fat to fill! Using your own blood to rejuvenate!), we're seeing an entirely new 'look' that's very different to what we're used to. In fact, it makes it increasingly harder to put your finger on what is actually… different about someone.

Mamamia spoke with Sydney cosmetic doctor Dr Yalda Jamali from Epios Cosmetic Clinic, who shared what she's observed when it comes to celebrity faces.

"Some celebs have always had subtle treatments, a great example is Kate Middleton. However many celebs who previously have gone for the 'done' look or have potentially taken it a bit too far previously are trying to undo this image and going towards a more natural cosmetic look," she told us.

"It is really hard to have 'undetectable' cosmetic surgery. Surgery is permanent, leaves scarring and usually can be noticed, especially in those that are constantly in the eye of the public."

Meaning? Everything you see on social media might not tell the full story. Classic!

However, another factor that might play into it is when people are actually opting to go down the cosmetic surgery route — the demographic, Dr Jamali said, is trending younger.

"Those that seek cosmetic surgery are turning to it as an option slightly younger. You are more likely to see much more subtle results in someone who doesn't have extensive signs of ageing. A surgical brow lift in someone who is in their 30s will look more subtle than a full surgical face lift in someone who is 60," Dr Jamali said.

Together with this is the change in aesthetics. It's something that's been bubbling under the surface for a while now and the aesthetic industry has just finally caught up. Sparked by a noticeable shift in almost every aspect of fashion and beauty, we're seeing the birth of a 'new look' right in front of our very eyes. And on the faces of almost every celebrity you follow.

After the rise of the Kardashian-fuelled 'Instagram Face' a few years ago, people are now gravitating towards a natural look more than ever in all aspects of beauty — from skincare to makeup and now, aesthetics.

"People are noticing that the 'frozen' look actually isn't nice or natural," said Dr Jamali.

Instead, it's all about subtle 'facial rejuvenation,' using technical advancements and of course a shift of focus towards skincare, with game-changing procedures and treatments focusing on the health of your skin.

Read: It's less about filling your face and more about working with what you've got.

"Cosmetic medicine as a field has also massively enhanced in the last 10 to 15 years and we have so many more options when it comes to treatments than ever. A lot of these treatments focus on skin quality rather than changing how you look which is promoting the more natural and 'quieter' cosmetic look. Energy-based devices are far more advanced and popular, and many non-surgical cosmetic treatments stimulate our own natural collagen and elastin rather than volumising or freezing the face."

Sharing what's she seeing in her own clinic, Dr Jamali said patients "rarely enter my clinic wanting to change how they look but mainly to improve their skin quality and prevent premature signs of ageing."

"I am also seeing that patients are happy to follow along on a long-term skin plan rather than a one-off treatment that may augment their features. Patients are also understanding that one-off quick treatments cannot possibly improve skin quality and it is a long-term commitment with both in=clinic treatments and at-home extensive skincare." 

When it comes to celebrities like Christina Aguilera, Lindsay Lohan and Matt Damon — and the exact treatments they've undergone — Dr Jamali told us, "It is hard to comment on what individuals have had (and not right to do so) if you aren't the treating doctor." However, in general, she said many celebrities use a combination of different treatments, turning to both surgical and non-surgical cosmetic procedures.

Again, it's also about skincare — and celebrities just happen to have access to some of the best treatments and devices in the world, right at their fingertips.

"It is also important to note that many are focusing on their skin quality and would have access and the funds for continuous skin treatments which does not necessarily change how you look but improves your skin quality. These will include energy-based devices such as lasers," she said.

In a now viral clip, the Blonde Files host Arielle Lorre invited hosts of Gloss Angeles, beauty journalists Kirbie Johnson and Sara Tan, to share the most common 'undetectable' procedures people are doing in LA.

Johnson said, "Blephs are the buzzword. Everyone is getting their eyes done. Obviously it's a surgery but it's not super invasive, like a lateral brow lift. I think a lot of people are into it to refresh their eye area."

"Also, I think we're in this world where fillers and neuromodulators are a part of people's beauty routines at this point. Once the [injectables] stop working in certain areas around their eyes, they're like, 'What's next? What else can be done?'" she shared.

"If you notice somebody looks really good and you can't put your finger on it, chances are they've had a rhinoplasty."

Tan chimed in, "Something that people notice but they can't put their finger on are the veneers."

"Taylor [Swift] has amazing veneers. Whoever she's going to now, nailed it," Lorre added.

Specific procedures and treatments aside, what does this all mean for us mere mortals? Because whatever beauty standards are running the show in the elite social circles of Hollywood, eventually trickle-down into the public, right? (Ozempic, we didn't see you walk in).

So, is this new era of beauty a good thing?

"This new era of aesthetics is slightly more positive," Dr Jamali told us.

"I hope the new era celebrates the signs of ageing, especially in women. Ageing is inevitable and you're always going to look much better as a glowing 40-year-old compared to a 40-year-old that's trying to look 30. I do think the new era unfortunately promotes surgery in younger patients (under 30) and this will have implications long term."

Ultimately, women's expectations of how they want to look as they age have changed. But is this just another unattainable pillar of 'beauty' we're trying to uphold? Because make no mistake — the pursuit of perfection is certainly not dead.

What do you think of the above? Share your thoughts with us in the comment section below.

Feature image: Getty/Canva.