A chemical found in many New Zealand plants - including the kōwhai - appears to be just as good as a more expensive medicine for helping people quit smoking.
Called cytisine, the plant extract has been used for decades in smoking cessation treatment in some Central and Eastern European countries, but remains relatively unknown elsewhere in the world.
Along with being cheaper compared with other medications, it also has few known side effects.
"This is a quitting tool that comes from a plant, instead of a lab," University of Auckland researcher Associate Professor Natalie Walker said.
To Māori, a new study led by Walker, and further highlighting cytisine's benefits, was another illustration of the rongoā - or medicinal properties - of the kōwhai.
"Identifying the potential of the cytisine component of the kōwhai is part of the revitalisation of matauranga Māori [Māori knowledge]."
The study, carried out in collaboration with Brunel University London and Lakes District Health Board, involved hundreds of Māori participants - most of them women - from across the Bay of Plenty.
On average, the participants were aged 43 and had smoked for about 25 years.
Of those who took cytisine pills, 12 per cent still weren't smoking six months later, compared with 8 per cent of those who took varenicline, a Government-funded smoking medication marketed as Champix.
People taking cytisine also experienced fewer side effects such as nausea, headache, and difficulty sleeping.
"Varenicline is New Zealand's best smoking cessation medication available, but also expensive for the Government," Walker said.
"Cytisine is cheap, it works, and it suits Māori and their whānau."
In earlier research also funded by the Health Research Council, scientists from the university showed cytisine was more effective than nicotine replacement therapy, such as nicotine patches, gum or lozenges, at helping people stop smoking.
Both cytisine and varenicline worked in the body to reduce the feeling of satisfaction that smoking gives and to stop the unpleasant feelings that come after stopping.
Lakes DHB chief executive Nick Saville-Wood welcomed the results of the trial, as would many of the local people who volunteered to take part.
He said there were a range of effective options to help make quitting easier.
"Supporting people to stop smoking is a priority for Lakes DHB and we were pleased to be able to support this study."
Study co-author Mary-Kaye Wharakura added: "He mihi nui whakaharahara tēnei, i whai wāhi ahau ki te hikoi ngātahi, ki te tautoko hoki i a rātou e aukati ana i te kai hikareti, ka mau te wehi."
("It was a privilege to be on their quit journey each and every step of the way. They were simply awesome.")
Bay of Plenty DHB acting general manager planning and funding Mike Agnew said the findings of the study were very encouraging.
"The advent of a naturally occurring compound, particularly one of New Zealand origin, will resonate within our most affected communities, and hopefully see rates of smoking cessation increase."
The study has been published in the international medical journal Addiction.