The drug network exposed by Matthew Perry's death

Before he died, alone in his jacuzzi, Matthew Perry had received three injections of ketamine in the space of just six hours.

"Shoot me up with a big one," he told his personal assistant, ahead of the final, fatal dose. According to court documents, in the period leading up to 28 October 2023, Kenneth Iwamasa was illegally administering Perry with between six and eight shots of the drug, an anaesthetic that can have hallucinogenic effects, each day.

A live-in assistant, he admitted to finding the actor unconscious at his Pacific Palisades home on at least two occasions in the weeks prior. The hit that ultimately killed the Friends star was supplied by Jasveen Sangha, also known as the "Ketamine Queen" - a dealer who apparently only dealt "with high-end and celebs".

She has now pleaded guilty to five charges. Her charges, along with others filed against Iwamasa and others over the supply of ketamine to Perry, exposed part of Hollywood's underground drug network - and put the spotlight on the world of celebrity, money and power.

'Yes men' with terrible consequences Perry's death was met with both utter shock and a sad sense of the inevitable. The world knew him best as Chandler Bing, the comic heartbeat of Friends.

But behind the jokes and the sarcasm, he was deeply troubled. "It almost felt like we'd been mourning Matthew for a long time because his battle with that disease was a really hard one for him to fight," is how his former co-star Jennifer Aniston described his addiction in a recent interview.

"As hard as it was for all of us and for the fans, there's a part of me that thinks this is better... I'm glad he's out of that pain." The actor was an addict, and vulnerable - but also a huge star, worth millions.

Iwamasa was administering the injections, ultimately playing God - but to him, the power most likely lay with his famous boss. His actions may seem inexcusable, but did he feel he had a choice? "I think it was a situation that increasingly got more and more out of control," says Bonnie Low-Kramen, a former celebrity assistant turned trainer, and author of Be The Ultimate Assistant.

Those who do the job, especially in Los Angeles, can be put under an enormous amount of pressure, she says, "tasked with doing things many of us wouldn't imagine carrying out for our employers. It is a job which comes with an inherent power imbalance".

Which means it can be incredibly hard to say no. "When people are rich and famous, they often have people around them who won't say no," she says.

"And assistants are in the yes business anyway. "We're in the business of figuring out, 'well, let's solve the problem...'.

When money is no object, there are new rules that apply in that situation and that can be really hard to handle." Iwamasa is not the first celebrity assistant asked to administer or pick up illegal drugs, she says, and Perry is not the first star to die after taking drugs. Ms Low-Kramen highlights the deaths of Janis Joplin, Prince and John Belushi as just a few other examples.

"Unfortunately, there are so many examples of this tragic end, where the abuse of drugs gets to a point where they've handled it for a really long time, and then the day comes when it can't be handled anymore." For those struggling with addiction, being surrounded by "yes men" can have terrible consequences, says Garrett Braukman, an addiction treatment executive in Hollywood. "Treatment is difficult for people when they have yes men.

They have a lot of people that are going to tell them you can get whatever you want, you can get drugs, you can get alcohol, you could do whatever, and no one is willing to really look at that from the perspective of how dangerous that is." Read more:Obituary: The one who made everyone laughMatthew Perry: A life in pictures Mr Braukman says addiction can go hand in hand with fame and that a "high" percentage of his patients work in the entertainment industry. "I don't know how I would be able to stay clean and sober if I go to my grandma's house and there's 20 guys outside of my grandma's house taking pictures of me walking in.

You become an animal to a degree that people are watching." Rise in use of ketamine The use of ketamine recreationally has been on the rise in recent years, in the UK as well as the US. In England, some 3,609 people started treatment for problems with the drug in the year 2023-2024 - more than eight times the number in 2014-2015, when 426 sought help, according to government statistics.

In January, drag queen The Vivienne was found dead in the bath at their home in Cheshire, aged 32. The star's family later told how the performer had died "from the effects of ketamine use causing a cardiac arrest".

Ketamine is usually taken recreationally as a crushed powder, but also sometimes injected or swallowed - making people feel detached and dreamlike. It can also cause severe bladder and kidney problems.

Perry's struggles with alcohol and other drugs, before ketamine, were long running and well documented, starting with drinking as a teenager before moving on to painkilling prescription drugs Vicodin and OxyContin, and tranquilliser Xanax. "I have spent upward of $7m (£5.8m) trying to get sober," he wrote in his memoir, released when he was clean, just a year before his death.

While accepting the almost unsurpassable legacy of the hit show that made him a star, he said he hoped his support for fellow addicts would be the achievement he was best remembered for. "When I die, I don't want Friends to be the first thing that's mentioned - I want helping others to be the first thing that's mentioned and I'm going to live the rest of my life proving that." He only lived for another year.

Illegal use v therapy Before he died, Perry had been undergoing legal ketamine infusion therapy to treat depression and anxiety. The drug can be used as a treatment in clinical settings in the US, and some specialist and private centres in the UK - although there are concerns from some medics here about its use even in those settings.

According to a postmortem report, the actor had reportedly been clean for 19 months before he started obtaining the drug illegally as well. It was not the supervised doses that killed him, but the idea of an addict taking the drug to help their problems might still sound shocking.

In California, ketamine drips are legally used as pain relief, to treat mood disorders and to help with addiction. Other celebrities and notable figures - including Chrissy Teigen, Elon Musk and Sharon Osbourne - have all shared details of ketamine therapy and how it helped them.

Dr Austin Harris, owner and medical director at NeuroRelief Ketamine Infusion Therapy, says historically the drug is "extremely safe" when used in the right conditions, and swears by its effectiveness. At the clinic in California, he explained to Sky News how it can help people with mood disorders and chronic pain, as well as those in recovery from drug or alcohol abuse.

"Which a lot of people who don't really understand this at a scientific level might think is an oxymoron," he says. "But actually, it's profoundly beneficial - done properly - in resetting both neurologic and psychological patterns for substance abuse." Ketamine infusion "restarts in our brain what should already be there.