“I have had so much plastic surgery,” said the late Joan Rivers, “when I die they will donate my body to Tupperware.” The late comedian went under the knife many times, but cosmetic surgery is far less popular than even just a few years ago. After hitting a record high in the UK in 2015, when 51,140 surgeries were carried out, numbers had dropped to 28,347 by last year.

Instead of operations, more people are opting for non-surgical “tweaks”, such as facial fillers and Botox. And rather than these procedures being the preserve of older people trying to stave off the signs of ageing, fillers are all the rage among the young, from girls in their teens up to women in their 30s. (It remains an overwhelmingly female market.)

The cosmetic surgery industry in the UK is worth £3.6bn, and non-surgical treatments account for nine out of 10 procedures, worth £2.75bn. While these treatments still involve needles and cost several hundred pounds a go, “tweakments” are seen as no big deal. In a new two-part BBC documentary, The Truth About… Cosmetic Treatments, some young people across the country liken fillers to “going for a hair cut”. Experts are not so sure.

Facial fillers

Fillers are a small injections of gel, often made of hyaluronic acid – a natural compound which dissolves in six to 12 months – which fills wrinkles and can add volume around the eyes, cheeks, mouth, jawline and lips. The UK is the fastest-growing market in the world for facial fillers – seen as a less expensive, less long-term option than surgery – and there is always a new treatment on offer as the technology advances.

The latest filler trend on the market is the “liquid nose job”, or a non-surgical rhinoplasty, where fillers are injected to “straighten” any bumps or crooks. It is said to last two years. It is popular because it can cost £400 as opposed to a £5,000 surgery, and it can be done in a quarter of an hour on your lunch break.

Another is the “tear trough filler”, which sees watery acid injected into the area below the eye.

Former A&E doctor Dr Wassim Taktouk has been a cosmetic doctor for 11 years, and has seen a massive change in the age of patients, and the work they want done.

“We used to think of cosmetic surgery as rejuvenating someone,” he tells i, “but now younger patients are coming in for beautification, a sharper angle to their jawline or a brow lift, or the really popular one being lip fillers.”

He has had 16-year-olds come in with their mums, but says he turns them away.

‘Red carpet ready’

Dr Taktouk says patients show him pictures of themselves filtered on Instagram and ask to look like those. The social media app is also used to drum up business – one UK-based practioner recently ran a competition to win a “Red Carpet Ready Package”, consisting of “4ml of Revolax to be used anywhere on the face – RRP £450!”

And just as women used to ask their hairdresser for “The Rachel”, Jennifer Aniston’s glossy bob in Friends, girls now take in pictures of famous women to show the face they want.

“Kylie Jenner has a lot to answer for,” says Dr Taktouk, “as does Love Island.” The “trout pout” is out, he says, with more customers preferring full but “natural” lips, wide eyes, a straight nose, sharp cheekbones and an all round sleekness. Like a perfect, seductive feline. Or a Kardashian.

Kylie Jenner, the 23-year-old reality star of Keeping Up With the Kardashians, looks like a different person after cosmetic procedures. Some of this may have been surgery, as she hasn’t confirmed what she has had done, but her love of facial fillers is evident and has caught the imaginations of teens and 20-somethings who have see how much it is possible to change a face.

Normalising ‘tweakments’

Mehreen Baig, who presents the documentary, met women who cited celebrities as their inspiration for fillers.

“Because of the amount of editing, angles, filters there are, on social media,” she says, “we start thinking a lot of these celebrities and influencers look like this naturally, and you start comparing why you don’t look like that naturally.”

Except, of course, it is so often not natural. While the normalisation of “tweakments” might be an anathema to those who thought this sort of thing only happens in Los Angeles, others feel it is better than invasive surgery. However, the long-term effects of repeated procedures are not yet known, and it is easy to overdo the injections.

Rogue practitioners are offering treatments on the cheap across the country – and unlike the US, non-surgical treatments are entirely unregulated in the UK. In 2017, Save Face, a company running a government-recognised national register of accredited practitioners, received almost 1,000 complaints about “tweakments” going wrong, with over half about fillers. There were also cases of blurred vision caused by wrong needle placement. In the documentary, a woman cries with relief when the acid in her lips is dissolved, after a rogue treatment left them swollen for a year.

“I hope it won’t take a big disaster for people to realise the law needs to change,” says Dr Taktouk.

Science continues to offer ways to supposedly upgrade our appearance. But as thousands of young people in the UK get their faces injected as casually as they would get a manicure, what does this mean for teenagers of the future?

Dr Taktouk has a test for young patients who come to him for fillers. He asks whether they think getting a liquid nose job will mean they get the boyfriend or job they want. If the answer is yes, he is cautious.

“You can put filler on their nose, but they still don’t have a boyfriend or don’t get that job. Sometimes it is that they don’t need the procedure, and they actually need something completely different in life.”

The Truth About Cosmetic Treatments begins at 8pm on Tuesday on BBC1