Demi Moore's terrifying flick The Substance is reviving a horror trend that has been neglected for decades (but it's leaving people traumatised)

Demi Moore 's latest film has hailed in a new era for an often-forgotten about film sub-genre - body horror.

When most cast their thoughts to the horror genre, images of ghosts and ghouls might first spring to mind.

But The Substance - a blood-soaked dystopian satire of the male gaze starring the 61-year-old Love Sonia actress - is slowly changing that, with the graphic body horror going mainstream and attracting cinemagoers across the globe.

The sub-genre defines films showing graphic violations of a body, and found its classics including Rosemary's Baby and Alien , some 60 years ago, but its popularity somewhat waned during the 2000s.

However, The Substance is reviving the genre, with the film's dramatic levels of gore commanding critics' attention, including the Evening Standard's Nick Howells who described it as the 'best and maddest film of the year so far', giving it five stars.

Body horror themes have been evident in literature for some time, including Mary Shelley's 1818 Frankenstein that saw a scientist manipulate human anatomy to create a so-called perfect specimen.

While its history can be rooted back hundreds of years in literature Canadian filmmaker David Cronenberg, 81, is hailed as one of the key figures in establishing the sub-genre on screen.

His films, including the 1977 film Rabid, and The Fly, released in 1986, incorporated visceral body transformation via circumstances including infectious diseases.

In that time, body horrors started to go mainstream, encouraging viewers outside of its niche fanbase to experience the sub-genre.

Rosemary's Baby, released in 1968, scooped 13 awards, and explored the body horror sub-genre in relation to pregnancy.

In 1979, Ridley Scott's Alien, which won an Oscar for best visual effects in 1980, found itself at the centre of a media buzz, despite the gory film showing images of human bodies torn apart by extra terrestrial life.

Fast forward to the early 2000s and directors continued to create body horrors, but few found mainstream success, with many failing to attract a widespread audience.

It's a challenge that, with the help of Hollywood's highest-paid actress, The Substance has managed to change.

Starring Hollywood's Demi Moore , The Substance tells the story of Elisabeth Sparkle, a famed aerobics instructor with a televised show.

Unceremoniously sacked as she hits her 50th birthday, Elisabeth discovers a black-market drug which can create a 'younger, more beautiful, more perfect' version of its user.

The drug's strict conditions are gruesome, and Elisabeth's need for youth to sustain her career talks directly to Hollywood's abandoning of actresses as they age.

But it's The Substance's 'deliciously unhinged and dread-inducing' levels of gore that have really commanded the critics' attention, with one describing it as 'a shocking assault on the senses'.

The film sees Elisabeth dealt a devastating blow on her birthday when she is fired by ruthless executive , played by Dennis Quaid.

Feeling rejected by a town that once loved her and despairing over her bygone star power, Elisabeth learns from a handsome young nurse about a black-market drug that promises to turn the user into a 'younger, more beautiful, more perfect' version of them self.

Though Elisabeth initially tosses the phone number in the bin, she soon fishes it out in a desperate panic and places an order.

The one rule to follow is that Elisabeth and her better self Sue (Margaret Qualley) must trade places every seven days.

So for one week at a time, she is forced again to live as her 50-year-old self.

But the allure of youth and a made-for-TV derrière proves too strong to resist that she tests the boundaries to see what the worst that can happen is if she squeezes an extra day or two in.

It's a rare body horror that has achieved critical praise. The Evening Standard's Nick Howells described it as the 'best and maddest film of the year so far' as he gave it five stars.

'Caveat: as long as you like a full portion of body horror and are happy to be spattered head to toe in blood and mutant body parts,' he wrote.

'It all climaxes way beyond where you could dare imagine it might end, in a riotously hilarious torrent of blood the likes of which you might never have witnessed before.

'A sledgehammer parable for the Ozempic generation, The Substance, with all confidence, is an instant classic.'

Meanwhile Krysta Fauria of AP described it as 'disgusting and deranged' as she wrote: 'The film's deliciously unhinged, blood-soaked and inevitably polarising third act is what makes it unforgettable.'

'What begins as a dread-inducing but still relatively palatable sci-fi flick spirals deeper into absurdism and violence, eventually erupting — quite literally — into a full-blown monster movie.'

For The Mail, Brian Viner wrote of the film's 'snapping, bursting, oozing and squelching' in his three-star review.

'There's plenty of popping in The Substance,' he said. 'Popping, in fact, might be the least of it, alongside snapping, bursting, oozing and squelching, in a grotesque body-horror satire that isn't for the squeamish but might be for the ticklish, if you can find the funny side.

'Yet for all its dystopian grisliness, Oscar Wilde would have recognised this story, which echoes The Picture Of Dorian Gray, but of course has particular resonance in today's looks-obsessed society.'

RTE's Bren Murphy added: 'Coralie Fargeat, the French director of 2017's powerfully violent Revenge, returns with The Substance, and when it comes to delivering more shocking visceral images with a message, she's not holding back.

'Darkly funny, intense, and extremely graphic, this is a shocking assault on the senses, in a good way - on second thoughts, in a masterful way.'

However, two critics weren't entirely sure its critique of the male gaze had landed.

Financial Times journalist Danny Leigh said: 'The longer the movie plays, the more you find other flaws. How gross beauty standards are, we are told, while for reasons that would be a spoiler, also being invited to shudder at elderly women's bodies.

'A satire of the male gaze this filled with young women twerking, they said, can look a lot like what it is meant to be satirising.'

While Clarisse Loughrey of The Independent noted: 'The Substance's final stretch descends into a full-blown, blood-fountain homage to gross-out cult classics like Brian Yuzna's 1989 horror film Society.

'It turns the body into a public spectacle and invites the audience in, a little too eagerly, to gawk at what has elsewhere been presented as such intimate, secret disgust.'