A low-cost drug not available in the United States is effective in helping smokers quit, a new study published in The New England Journal of Medicine has found.

The drug, cytisine, is a nicotine substitute that has been sold in Eastern European countries for many years. The study found people taking the drug were more successful in quitting than those taking a placebo, HealthDay reports. The study included 740 smokers who were randomly assigned to take cytisine or a placebo for 25 days. After a year, 8.4 percent of those who took cytisine were not smoking, compared with 2.4 percent of those who took a placebo.

The drug is not approved by the U.S. Food and Drug Administration. According to the article, it works in a similar way to nicotine replacement drugs available in this country.

Cytisine costs about $15 for a course of treatment in Poland, where the study was conducted. “Cytisine could save many thousands of lives, particularly in low- and middle-income countries,” lead researcher Robert West said. “But it could also save health care systems and insurers in high-income countries millions on their drugs bill.”