Fed up of using nicotine gum, patches or lozenges, or relying on walks, food treats or sheer willpower to beat your cigarette addiction? Pills bought online costing 12p each may just be your salvation.

The tablets in question, called Tabex, more than triple a smoker's chances of giving up, according to new research which is expected to lead to a rush of internet orders from Britons hooked on nicotine.

Their success is down to the active ingredient cytisine, which is derived from laburnum seeds. Its capacity to satisfy smokers' cravings was first discovered when Russian and German troops smoked laburnum leaves for that exact purpose during the Second World War.

Experts expect Tabex to prove as effective as existing aids to help people ditch their habit and could ultimately save the NHS tens of millions of pounds because they are so cheap.

A British-led research study investigated the drug's effectiveness. Of 740 smokers who took part in a trial, 8.4% of those who had taken between two and six Tabex a day for 25 days were able to quit smoking for a year, compared to just 2.4% of those who received a placebo.

But while it has been used in eastern Europe for decades, it has never gained a licence in the UK. Professor Robert West, who led the study, said he anticipated that publicity surrounding his findings would trigger a surge in people turning to websites to obtain it.

"It's been available in central and eastern Europe for more than 40 years, we have safety data on millions of people, and we know it's effective, but it's not licensed in Britain," said West, from the Cancer Research UK Health Behaviour Research Centre at University College London.

"People can make their own choices. A licence is not a licence to buy, it's a licence to market. There's nothing illegal about buying this drug online, but there's always the risk that you might not get what you want," said West. He and his colleagues were "extremely encouraged" by the results, published in the New England Journal of Medicine, he said.

A Department of Health spokesman said: "This drug sounds promising, especially as a lower cost alternative to help smokers to quit in developing countries. We will look at whether the medicine has prospects for use in the UK."

West said: "We recognise that stopping smoking can be extremely difficult and we hope that by using cytisine as a substitute for nicotine, the results of this trial could transform the health of nations around the globe by offering a practical option, even for the poorest smokers."

Tabex works in a similar way to Champix, which is already used by smokers trying to quit. But while a 12-week course on that medicine costs £100-£150, a box of 100 Tabex can be bought online for just £12. It mimics nicotine's effects by stimulating the brain's reward pathways.

Doireann Maddock, a senior cardiac nurse at the British Heart Foundation, which co-funded the study, said: "We need some bigger trials first, but this pill may yet offer a low-cost treatment to help people break this harmful habit."