A holiday from sunshine, certainly.

In one big room, 36 young people  lie in single beds: so many smiling and dazed faces, male and female, some bodies curled up away from the light, low-key conversations, heads buried in pillows, a hipster-bearded dude listening to music in a chilled after-party fashion. No amputations here, apart from being cut off from the outside world. Even so, it's like a World War I hospital ward.

This is mid-morning at Nucleus Network, the biggest of four private facilities in Australia that carry out phase one drug trials for mainly United States pharmaceutical companies. Phase one is when a new drug is tested on healthy people for safety, before it is trialled on sick volunteers in phase two and three, when efficacy is tested.

A few weeks before visiting Nucleus Network - which is wholly owned by, and housed within the Baker IDI Heart and Diabetes Institute - a man was left brain dead, and later died after suffering serious side effects during a drugs trial in France. Catastrophic reactions in drug trials are rare, at least in the western world. But The Sunday Age wanted to know if this awful news was playing on the minds of test subjects in Australia. It seems not.

In Nucleus Network's drug testing facility in Prahran - next door to the Alfred Hospital lest something goes wrong - the greatest burden may not be an adverse reaction (mercifully rare) but a lack of privacy, cabin fever and an endlessly evolving cloud of flatulence.

There's also the matter of having to stay in bed for four hours at a time after taking the experimental medication. Such is the case now. One fellow is sitting up, having his bacon and eggs. He needs to get it down in 20 minutes. He's being watched intently for any reaction as the food mixes with an experimental drug or a placebo - he doesn't know which. Given that test subjects are confined to this room for between 16 and 32 days, he may not know what day it is.

That's how it is for country boy Darcy, 28, trialling a new treatment for psoriasis. ''I think this is day 10 out of 19," he says.

We're in a nearby meeting room and Darcy is permitted to break routine to tell his story. He is a tall and fit, with the long muscled arms of a rower, bright eyes, perhaps unnaturally bright and wide open. He's sitting at a table with several of Nucleus's bosses.They sit quietly while Darcy answers questions.

This is Darcy's fourth trial in six years. He signs up whenever he's between work. ''When I'm searching for the next position, I come in here and it fills the gap," he says.

At $10 an hour, paid around the clock, Darcy will go home with $4560. It was ''definitely the money" that drew him to the cause, he says.

''I try and keep a routine," he says of his time in the facility. ''I do some stretching, meditate a lot, do some study (an online youth work course, on his laptop), some job searching. I get dosed in the morning and I have to be in bed four hours after that. On the afternoon, I go on a walk around the unit. Then I do more study and get dosed again in the evening."

His fellow trial subjects are ''a really good group, quite social". Half of them are travellers from the UK. Darcy says most of the Brits are saving up for the next leg of their travels. There are usually more students, he says.

It was Darcy's university friends who first sold him the idea of being a medical guinea pig for the cash.

Still, he was apprehensive. ''My parents were definitely apprehensive. They offered to help me out if I really needed the money."

From day one, however, Darcy says he's put his faith in the doctors. During the screening process, ''we get everything explained about what the drug trial is for ... the risks and side effects".

Darcy says he hasn't had any side effects and that the most taxing aspect is long hours in bed and the lack of fresh air. He is open to doing more trials and has referred others to it.

According to Nucleus Network's Managing Director Cameron Johnson, the company runs about 50 drug trials a year. There are some oncology trials using cancer patients, but phase one trials for  US companies  are 85 per cent of the work. Other customers are local and from India, Europe and China.

Overseas pharmaceutical companies favour Australia, says Johnson, because our regulatory framework means ''the speed at which companies can get trials approved in Australia is quicker, more streamlined than other jurisdictions such as Japan or Europe".

Also, data generated in Australia is acceptable to the US Food and Drug Administration and the European regulatory agency,  whereas data from developing countries is less reliable, in part because the health and fitness of participants is questionable.

Johnson says each trial at Nucleus employs between 24 and 120 healthy volunteers, which means up to 6000 volunteers a year are required. While there is reportedly a chronic shortage of sick patients for phase two and three trials - who arguably have more to gain from taking part in a trial - there is no such scarcity of healthy people signing up for phase one trials, including those like Darcy who have taken part in multiple trials.

Johnson says early phase clinical research is booming, largely due to commercial funding for drug development  having been more readily available over the  past three to five years compared with 2008 to 2010.

So there's plenty of work available for the likes of Darcy. In the US, an unknown number of people have reportedly become professional guinea pigs. Is that possible in Australia?

Perhaps. Johnson says that as long as adequate time is allowed between trials, repeat volunteers are fine. "If it fits a person's lifestyle, we will see people who may come back for a clinical trial. Naturally, if they're coming back for a second or third clinical trial, there's a lot of scrutiny around what the previous trial was."

Nucleus Network's medical director Dr Jason Lickliter says participation in multiple trials is governed by what's known as the ''washout period" - how long it takes for the trialled drug to be judged clear of the subject's body. This can vary from 30 days to up to five months.

Another factor is blood collection. ''When you do a clinical trial you might take a lot of blood from people for testing," he says. Hence, subjects need time to recover before entering a new trial.

The issue of money as a motivation for entering a drug trial is ethically a tricky one.  According to the federal government's National Statement on Ethical Conduct in Human Research: ''It is generally appropriate to reimburse the costs to participants of taking part in research, including costs such as travel, accommodation and parking. Sometimes participants may also be paid for time involved. However, payment that is disproportionate to the time involved, or any other inducement that is likely to encourage participants to take risks, is ethically unacceptable."

In other words, money - especially when offered to unemployed people - could be seen as coercion. And so the $10 an hour earned by Darcy - well below the minimum wage rate of $17.29 per hour - appears to be modest, no matter it adds up to several thousand dollars when he's being paid 24 hours a day.

''We don't publish that you get $5000 to do this clinical trial," says Cameron Johnson.

Nucleus Network has a separate recruiting website - the Centre for Clinical Studies - with a toll free number and its own Facebook page. No actual dollar figure is advertised by Nucleus or the three other companies operating in Australia - although a Perth-based company called Linear offers a $50 prepaid Visa gift card to people who refer friends or relatives as potential trial participants.

Still, the word gets around that decent money can be made - thanks to those backpacker websites, which provide direct links to Nucleus Network (Melbourne), Q-Pharm (Brisbane), Linear (Perth), and IDT CMAX (Adelaide). Strangely, there's no site for Sydney.

In fact, sites like downundr.com go beyond merely naming the opportunity, to discussing issues of safety. ''Sounds dangerous, but is it really??? Australia is one of the world's top medical research countries... If you are feeling a bit nervous about it, keep in mind, that while there is no guarantee that something won't go wrong, Australia is one of the world leaders in medical research. If there was a country you wanted to be in while doing a trial, Australia would be it."

That's probably right, if statistics are a comfort. Prior to the January catastrophe in France that left one man dead and four others brain damaged - an event that is only now being explained - the only drug trial to go horrifically wrong in the western world this century occurred in England, in 2006. No one died, but six men were left maimed after taking a drug called TGN1412 which was conceived as a possible treatment for rheumatoid arthritis and leukaemia. Within hours of taking the drug - at a dose that was said to be 500 times lower than the safest dose trialled on animals - six  healthy young men suffered organ failure. Some lost fingers and toes; others became known as Elephant Men because their heads swelled up and reportedly complained of feeling that their heads were on fire and their eyeballs were popping out.

Could it happen here?

There were peculiar problems with TGN1412 in that it didn't stimulate the immune system in animals, where in humans it led to immuno-toxicity. ''It didn't have the same response in monkeys and other pre-clinical animals," says Lickliter. ''I guess people knew that going in, and so they took a very low dose."

But essentially it wasn't low enough. So new protocols were developed where the initial dose of a drug, when ingested by a human being, is lower than the dose that has been shown to cause a reaction in human cell work.

Also, rather than testing subjects 20 minutes apart in the initial phase, a greater amount of time is now allowed to see if there is a reaction in the first subject. This is called sentinel dosing and is now industry practise.

In effect, drug trial disasters are like plane crashes. They're rare but dramatic when they occur, and they lead to further refinements in protocols.

The TGN1412 debacle also prompted a UK Government report and a British Medical Journal article which both called for more transparency and sharing of phase one data. In 2013, the BMJ  and a number of leading research bodies, called for all past and future clinical trials to release their patient data - the idea being that even small events might prove significant when tests run by different companies are compared and analysed.

Since then, 652 international health and medicine organisations, including the National Health and Medical Research Council of Australia, the Australasian College for Emergency Medicine, and the Royal Australian and New Zealand College of Psychiatrists have signed the AllTrials petition - but pharma companies resist the move on commercial and practical grounds.

In an email to The Sunday Age, Ben Goldacre, a doctor and co-founder of the AllTrials campaign for clinical trial transparency, said: "We have a responsibility to do all we can to make phase one trials as safe as possible for those who are brave and altruistic enough to volunteer for them. That means learning from past mistakes wherever we can. The medical, academic and regulatory community have still not fixed the known problems around phase one trial transparency that were identified during the UK government's own inquiry into the TGN1412 trial ... as long as we continue to allow dangerous secrecy to persist around such trials, we make these disasters more likely."

Last year, an Australian-led study, reviewing 14-year-old data related to a psychiatric drug, was reportedly the first of a new BMJ initiative to encourage misreported studies to be formally corrected and abandoned studies to be published.

News reports predicted that a steady stream of clinical trials from around the world were to be reanalysed and there would be a major shift in the way drug companies approach how they conduct and interpret trials and data.

Watch this space.

It's important to note that serious adverse reactions to drugs are reported, and rare. Nucleus Network says that ''less than 0.1% of volunteers in our experience have any type of acute medical response and symptoms experienced are brief and not long lasting in nature".

In Australia, clinical drug testing companies are required to document any unusual symptoms, such as headache or upset stomach, and this information goes to the pharmaceutical company.

Nonetheless, how does all this play on the mind of a test subject?

In March last year, Michelle Gallaher, an advocate of clinical trials who has worked in the biotech industry, became one of 230 Australians who took part in a year-long non-residential trial of the Ebola vaccine. The trial involved a number of injections of either the vaccine or a placebo (she still doesn't know which) and keeping a daily diary.

Gallaher said she wasn't participating for the money (about $1000) but because she was keen to help fight a terrifying disease that had killed more than 10,000 people in west Africa. She wasn't frightened of side effects because the drug had been tested on others.

"I'd never be [the first to test a drug]. If something is going to go seriously wrong, it will be in that first cohort."

The Sunday Age spoke by telephone with an Adelaide-based musician, aged 33, we'll call Mr Body. He'd actually lost count as to how many trials he'd taken part in for South Australian company IDT CMAX.  "Around 12 times I think," he said, "and no adverse reactions."

The drugs Body has tested include anti-inflammatories and several pain killers. "Which isn't as much fun as it sounds. Because they usually give you a blocker which negates any of the positive effects."

"Sometimes I'll take all the information to a GP before I do a trial and ask 'what do you think of this?' If my doctor says I definitely wouldn't do that, I won't. If he has no real concerns, it makes me feel a lot less worried," Body says.

Still, there have been moments during a trial, when some of his fellow subjects have started to feel ill, that anxiety creeps in. "It's never been anything really serious. But when they first get a headache or an upset stomach, you wonder what's going to happen next..."

When  he read about the French study, "people turning up brain dead", he felt grateful not to have suffered such a fate – but it also made him re-think about whether or not to do another study.

"I have turned down studies because the drugs seemed too risky. I think anything that affects your  immune system should be avoided. And I'd never want to be number one. I'd want to know other people had already tried a drug before I took it. I'm not ruling out doing more. I have faith in the ethics board and in the historical record. To my knowledge,we haven't had anything go majorly wrong in Australia. If it did, I'd be done. No more."