Can you buy a good night's sleep?

Forty per cent of Australians have trouble sleeping, and the market has responded with a mind-boggling array of sleep aids. But do any of them actually work? The Weekly goes in search of slumber.

- GENEVIEVE GANNON

Last spring, wellness mogul Gwyneth Paltrow took to Instagram to announce she'd discovered that the secret to optimum sleep was taping her mouth shut before bed. "Breathing through your nose at night apparently creates alkalinity in the body and promotes best quality sleep," Gwyneth declared. She shared a photo of the tape she uses ($37.50 for 90 strips) and unleashed an army of copycats who echoed her enthusiasm across the internet.

Sleep expert Dr Carmel Harrington says the kernel of science at the heart of this viral craze is that, when you breat through your nose, you humidify and warm the air before it hits your lungs. But you don't need to spend almost $40 on designer tape to reap the benefits. "We are all natural nose breathers," Dr Harrington says. "If you're not a nasal breather, there might be a reason, so don't go and tape up night after night, and ignore the underlying issues."

Using a thin piece of surgical tape to keep your mouth shut can provide short-term relief from some sleep conditions, Dr Harrington says, but sealing your mouth shut horizontally with a big strip of tape is at best pointless, at worst dangerous.

As a sleep researcher, Dr Harrington gets frustrated when she sees expensive and ineffective solutions being peddled by people out to make a buck. "A lot of these things are born of research, but the commercial interest makes it bigger than it is," she says.

Australians are sleeping 1.5 hours less than they were in the 1960s, with 12 per cent reporting fewer than 5.5 hours of shut-eye a night, according to a Sleep Health Foundation (SHF) survey. That compares to an optimal 7-9 hours. Unsurprisingly, we're eager for solutions, and the business of bedtime is booming: Mattress sales alone are on track to exceed half a billion dollars in Australia this year, and brands are investing in sophisticated tech to wow us and win our business.