Cytisine is finally emerging from behind the Iron Curtain as a viable treatment to help people quit smoking.

Smoking accounts for more avoidable public health damage than anything else, including obesity. The path to giving up the vice is paved with smoking cessation aids, such as nicotine gums and patches and the drug varenicline (Chantix).

But there’s another treatment that works at least as well. Though it’s been in use since the 1960s, many American doctors have never heard of it. It costs a fraction of what Pfizer’s Chantix does, and it’s even cheaper than patches and gums.

The treatment is cytisine, a plant-based drug that blocks nicotine receptors in the brain much like Chantix does. The drug has been used to treat more than 20 million people.

According to a study just published in the New England Journal of Medicine, it is at least as effective as nicotine replacement in helping smokers quit and avoid relapses.

Natalie Walker, Ph.D., a research fellow at New Zealand’s National Institute for Health Innovation, tracked 1310 patients who had called New Zealand’s smoking-cessation hotline. The groups were randomized by ethnicity, gender, and level of addiction.

Half of the volunteers got nicotine replacement therapy and half got cytisine. Both groups got behavioral support as well, which public health groups say is a key part of any effort to quit.

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After one month, 4 in 10 people using cytisine said they hadn’t smoked. Among those who received nicotine-replacement therapy, 3 in 10 had avoided smoking. At two and six months, more cytisine users were still tobacco-free. The drug was particularly effective for women.

Dr. Norman Edelman, a senior medical advisor at the American Lung Association (ALA), said the group “is happy to see a new entity available for smoking cessation.”

The ALA encourages people to quit smoking, however they do it.

“Quitting smoking is the single best thing you can do to improve your health and extend your life,” Edelman said.

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If smokers can quit for less money, all the better.

Most of the world’s smokers live in developing countries and can’t access high-cost smoking cessation aids. According to World Health Organization data, smoking rates are highest in Pacific Island and Eastern European nations. In Latvia, one-third of all adults smoke.

Even in developed countries, the high cost of nicotine replacements can hurt consumers’ pocketbooks and government coffers.

Cytisine, which Walker called “the poor man’s varenicline,” may be more practical.

According to the new study and to the consumer drug comparison site GoodRx, a 25-day standard course of cytisine runs about $25. One month’s worth of varenicline costs roughly $300. (At the median cost in the United States, a pack-a-day smoking habit costs slightly more than that.

The cost of nicotine replacement varies, but a month’s worth of nicotine patches goes for about $80.

Read More: Do E-Cigarettes Help Smokers Quit? »

“Cytisine is really, really cheap and it’s quite effective, so why isn’t it everywhere?” Walker asked.

One reason is the side effects, which were more common in the study group taking cytisine. Of those with side effects, more than 80 percent said they would recommend it. The side effects are similar to those of Chantix: bad dreams, nausea, and vomiting.

The bigger issue is a knowledge gap about the drug.

“Most of the research [on cytisine] has been undertaken in countries that are non-English speaking and the studies are published in journals that aren’t in English. So the Western world just ignores them,” Walker said.

The studies that were used to develop dosing recommendations, for instance, are not publicly available.

Four European Union countries have approved the drug, while 12 countries outside the union have, according to Walker. The Food and Drug Administration has not approved it for use in the United States.

Extab Pharmaceutical holds the licensing rights to one of two brand name versions of the drug, Tabex. The company plans to conduct a clinical trial of Tabex in the United States. Extab is backed by a pharmaceutical investment company that brings neglected drugs to market.

Walker’s goal for the study was to open the door for more research on the drug in Western countries.

“We need to get to know more about this medicine,” she said.

See the Effects of Smoking on the Body »