A plant-based chemical compound found to be more effective than nicotine replacement therapy in helping smokers quit is also found in kowhai, a researcher says.
The study, published in the New England Medical Journal, showed smokers who received cytisine for 25 days were more likely to quit and still be smoke-free at six months.
Lead author Natalie Walker said cytisine products had been made in Eastern Europe for the past 40 years and the active ingredient was found in many plants, including kowhai.
But she cautioned against people making their own medicine.
"It's very important people don't go out and start picking bits of these plants off and using them because it's actually very toxic," she said.
"So the cytisine that's used in the pills is a very, very low dose."
Dr Walker said the drug was little known until recently because all the research was in German and Russian.
However, she believed it should be made more widely available.
"The main thing is try and get cytisine out into the western world, and that requires the pharmaceutical companies that make it in Bulgaria and Poland to start to apply for regulatory approval through the various governments such as in the USA and the UK and New Zealand," she said.
"Once they get regulatory approval, then it's accessible to people in the country."
Dr Walker said cytisine offered a chance for poorer countries to access a low-priced quit remedy.