Pumping digital cigarettes full of liquid nicotine into the lungs is just as easy as putting a few drops of water in.
The process is simple: put the liquid into the digital cigarette and inhale.
However, digital cigarettes are no longer the only devices that can deliver nicotine.
The US Food and Drug Administration is considering regulating the use of vaporisers as a nicotine replacement therapy.
But some experts are sceptical.
The devices are now on the market in countries including Australia, Canada and New Zealand, but they are banned in the US.
Some argue they pose too great a risk of addiction.
But a growing number of research studies are suggesting they can be beneficial.
“This is something that people are starting to notice is having a beneficial effect,” Dr Matthew Gartner, a pharmacist from the University of Sydney, told Next Big Futures.
“It’s something that is not really on the radar, and certainly not as a health concern.”
But, Dr Gartners said, there were no studies that demonstrated that the inhaler worked as well as a digital device.
“The idea that we could use a vaporizer and put it in your mouth, there are a lot of risks,” he said.
“We are looking at the potential risks to our patients and the public health.”
But the FDA is still considering whether to ban them, and is expected to do so next month.
In a statement, the agency said: “The use of digital cigarettes is currently regulated in the United States by the FDA and the FDA has not yet issued an order to address the use and safety of these products.”
However, the US Consumer Product Safety Commission, which oversees the safety of electronic cigarettes, is urging the FDA to regulate them as a tobacco product.
It said: ‘It is imperative that FDA address the safety and efficacy of electronic cigarette products, including the use by consumers as a substitute for cigarettes, in order to promote the public’s health and safety.’
And a spokesperson for the National Institute on Drug Abuse said the agency was still reviewing the science.
‘There is no data to support the claim that electronic cigarettes pose a higher risk to the public or to people with tobacco or alcohol addiction,’ said the NIDA spokesperson.
“In addition, it is critical to review existing data on the potential health effects of electronic nicotine delivery devices and the potential public health benefits from such devices.”