Hollywood confidential

SO, WHICH tanorexic Hollywood superstar speaks of herself only in the third person, has her pet pooch's fur dyed an electric shade of purple to match her latest couture disaster and is a monster midget in Manolos, with the IQ of a two-year-old?

And who is the loud-mouthed female British rock star who's been known to hand her long-suffering make-up artist a Bic razor, sterilised in Coca-Cola, because she plans to reveal her basic instincts and hasn't had time to have a Brazilian?

Well, take your pick really, since we're in La-La Land. Although, when I pester authors Ruthanna Hopper and Amanda Goldberg to name names their lips are sealed.

The aforementioned characters turn up in Celebutantes, a sassy, scandal-filled new novel the pair have written about the barking-mad world of modern moviedom, in which nothing succeeds like excess and nutty actresses bless their Oscar-night frocks with Native American sage; where starlets meet therapists between sessions with personal trainers, stylists, acupuncturists, massage therapists and astrologers.

Their narrator heroine is a fictional amalgam of both Goldberg (33) and Hopper (35), although they're reluctant to admit it. She's Lola Santisi, a 26-year-old member of Hollywood royalty without a kingdom – or even a condo – to call her own, 5ft 7-and-a-half (in four-inch Jimmy Choos), the daughter of a 250lb, Oscar-winning film director and a former model "who'd done her time with Warren Beatty, Mick Jagger, and Richard Gere, pre-the Dalai Lama".

Likeable Lola is, according to her therapist, an Actorholic – hopelessly addicted to dating narcissistic actors because she is trying to work out her relationship with her narcissistic father who's incapable of loving anyone other than himself, etc, etc … She's also suffering, in psycho-babble terms, from Career Deficit Disorder, which is apparently very common with the "Adult Children Of's" among Hollywood's caste-driven dynasties.

A failed fashionista and actress, Lola is persuaded by her Gay Best Friend, designer Julian Temple, to become "a Hollywood ambassador", ie she will persuade A-listers to get dolled up in his fabulous frocks on Oscar night. Set over six days in the run-up to the self-congratulatory orgy of the Academy Awards, it's a deliciously witty, whirlwind send-up of a world that appears to be beyond satire. Indeed, Hopper and Goldberg admit that it was the fact rather than the fiction that their publishers refused to believe, such as the story about the dazed and confused punk rocker who made her assistant shave her "Netherlands" – in the published version she does it herself, albeit in a room filled with embarrassed hangers-on.

The truth about the real star involved in this bizarre event, whispered to me over Fiji water, is much more gross – and certainly not suitable for a family newspaper like The Scotsman. "Every story we tell in this book happened," says Goldberg.

"It's just that we attribute them differently," adds Hopper. "It's all based on our life experience. But we've really toned it down because everyone who read our earlier drafts kept saying, 'It's too over-the-top!' Even though it was real. It's such a clich, but you couldn't make any of this up, because, however ridiculous, it's already happened."

Both women are "Adult Children Of's", although neither has ever suffered from Career Deficit Disorder. With the publication of Celebutantes being touted as "2008's most bling-toting, name-dropping, gossip-packed, celeb-filled read", their careers will doubtless go stratospheric, because it is surely destined to be the most talked-about Hollywood book since Jacqueline Susann's Valley of the Dolls in the Sixties.

Their chums Jackie Collins, Dominick Dunne and Anjelica Huston – who has a walk-on role in Celebutantes – have given it their blessing. Even fashion designer Tom Ford (who features as the camp-as-Christmas Julian's sexual fantasy) is a fan.

Well-connected daughters of serious power players in the business, Hopper and Goldberg have been privy to the secrets of the stars since childhood. Goldberg, for example, is a lifelong friend of Drew Barrymore. And that's Hopper as in Dennis, by the way, while Goldberg's dad Leonard is the veteran film and television producer of such hits as Hart to Hart, Starsky and Hutch and Charlie's Angels – he also produced the blockbusting Charlie's Angels films, on which his daughter was associate producer.

Actress Hopper produced and co-starred with her father in the critically acclaimed indie film Americano (2005). She's also put together the CineVegas Film Festival in Las Vegas.

Their book is packed with fun gobbets of gossip: Diane von Furstenberg and her billionaire husband Barry Diller are "off" refined sugar, the designer reveals at the Vanity Fair Oscar party, while devouring their third order of sticky toffee pudding. Meanwhile mother and daughter actresses Goldie Hawn and Kate Hudson employ a spiritual guide to direct them through Oscar week so that they may "stay centred in the sea of superficiality".

And, if you should run into Demi Moore at your Rabbi's birthday party, she'll almost certainly prescribe her valerian root tincture as a treatment for your stress-induced insomnia.

Hopper and Goldberg are the sharp-eyed and sharper-penned observers of the world in which they grew up, but always, as Hopper remarks, the watchers rather than the watched. They come across as level-headed, sensible and decorous, well schooled in the art of behaving themselves, unlike so many other "Adult Children Ofs".

Hopper is dressed in a cream coat and jeans, with lots of ethnic jewellery, while Goldberg, described as "One to Watch" by Vogue and who has also made it onto the Harper's Bazaar Best Dressed List, is wearing an oversized grey cardigan, skin-tight jeans and Dolce & Gabanna stilettos.

Although they could both presumably live the lives of Hollywood golden girls, burnished with money, success and surly bad behaviour, you won't find a whisper about either of them getting legless, doing drugs, going commando or having sex with inappropriate people. They're most definitely not the Paris Hiltons of their generation.

So how have the friends managed to keep their feet so firmly on the ground?

"I didn't grow up in Hollywood, although I spent a lot of time here with my dad, who's a force of nature," explains Hopper, who was born in Taos, New Mexico post-Easy Rider, the film that made her father's name. "My father was quite out there!" Her mother is dancer and actress Daria Halprin (star of Michelangelo Antonioni's 1970 film Zabriskie Point).

Her parents separated when she was young, so she was raised in California's "magical" Marin County before studying acting in New York.

"Amanda and I grew up at very different extremes of the Hollywood spectrum," says Hopper. "My upbringing was much more bohemian, a rebellious background because I lived with my mom – who's now a therapist – and my step-father. But I was in and out of Hollywood. I'd come visit my dad a lot, but I didn't live here; I was always quiet and withdrawn around all these famous actors.

"There was a lot of observing for me, although I did go down the acting path for a while. Amanda, though, is real old-guard Hollywood."

Goldberg's aunt, Toni Howard, is a veteran Hollywood agent and her mother, Wendy, founded the California State Summer School for the Arts, while her dad has been head of programming at TV giant ABC and president of 20th Century Fox. "People can't fault me for being Leonard's daughter – I was always very protected, although I think it would be easy to hate someone like me – or our heroine Lola – for growing up in such a privileged world," says Goldberg, in her soft, little girl voice, adding that her mother has been an enormous inspiration, too.

Family dinners would include guests such as Michael Caine, Sean Connery and Sidney Poitier. "It just so happened that my parents' friends were famous so I did hang out with a lot of Children Ofs. Anyway, there's nothing I can do to change my parentage and I wouldn't want to – I'm proud of it. I've always felt that all I can do is do my best, be myself and not worry about whether people have a problem with me, especially when I was a film producer. It actually negated my voice, though, because everyone asked all the time whether I'd talked to my dad."

Goldberg first worked with her father, to whom she's close, on the Ashley Judd movie Double Jeopardy, after graduating from the University of Pennsylvania. She'd spent a year in Paris and another as an intern in the designer Todd Oldham's New York studio – she was introduced to him by Julia Roberts' agent, a friend of the family.

Both women always wanted to do something on their own, something separate from what their parents did. "The idea of following in Leonard's footsteps was daunting," Goldberg admits, while Hopper believes that it's their very different backgrounds that's made their writing partnership "juicy".

"We're completely dependent on each other – neither of us has ever spent so much time with another human being," she says. "But we've never had a fall out. We wrote every word together because both of us dreamt of becoming bona fide authors and of escaping Hollywood. Of course, we haven't. We ended up being engulfed in it, but I certainly think the book marks the fact that each of us is finally emerging from the long shadows cast by our famous fathers. Both of us have always wanted to do something for ourselves." She adds that the sequel takes Lola and friends to Cannes.

The pair met during Oscar week five years ago at the opening of an art exhibition of work by sculptor Robert Graham, who is married to Anjelica Huston.

"We were the quiet ones, watching the parade of supernovas from the sidelines. We discovered immediately that we're a couple of twin-heads," explains Goldberg, whom Hopper insists is in possession of a photographic memory.

"We ended up sitting together most of the night, just taking it all in," says Hopper. "Neither of us is the sort of girl who would get drunk and dance on tables without our panties," chips in Goldberg, who's single. Hopper is married to comedy writer Steven Brill, who has worked with Adam Sandler and directed the about-to-be released Drillbit Taylor starring Owen Wilson. Celebutantes opens and closes with the Vanity Fair Oscars night Red Carpet party, the "primo" event of the Hollywood year. "You've no idea of the heightened reality that is that extraordinary evening," says Hopper. "When the invitations go out, people are on tenterhooks. It's like waiting for your college acceptance letter – only a thousand times worse. Will Graydon Carter, the editor of Vanity Fair , say yes or no? Will it be a case of Vanity Unfair?

"It's the barometer that tells them who they are and where they stand. It's a crazy time – in fact it's a good time to get out of Los Angeles. Some people do, of course, so that it won't emerge that they didn't get an invite."

It's rumoured that obscene amounts of dollars are offered for tickets. "Oh sure," says Goldberg. "We've heard of bribes up to 300,000." And then there are the extravagant gifts that need bungalows all to themselves when Graydon's in residence at the Beverly Hills Hotel – mountain ranges of blue Tiffany boxes, orange Hermes boxes . . .

"Of course, there are freebies everywhere for the A-listers, from Vera Wang lace negligees to mink eyelash extensions, as well as hospitality suites where you can get anything free, from 1,500 porcelain snap-on teeth that will give you Jennifer Hudson's smile to an Oscar gold-toned, made-to-measure Miracle bra from Victoria's Secret to wear while posing with your 25,000 diamond-encrusted digital Nikon."

So will they get tickets for next month's VF bash, after Graydon Carter reads their beady-eyed take on his big evening?

"My parents always get an invite, of course," replies Goldberg. "Personally, I find red carpets really, really daunting. All those flashbulbs popping, everyone shouting at you!"

While Hopper shudders: "It's just way too scary! We may be out of town."

Celebutantes by Amanda Goldberg and Ruthanna Hopper is published on Thursday by Orion, priced 6.99.