Hatsukami DK, et al. - Study results previously suggested that smokers assigned to an immediate reduction of nicotine in cigarettes vs those assigned to gradual reduction over time or those who continued smoking normal nicotine content cigarettes display significantly greater reductions in number of cigarettes smoked and very low levels of biomarkers of toxicant and carcinogen exposure. Researchers conducted this study examining selected biomarkers associated with harmful biological effects in correlation to these approaches. In this three-arm, randomized controlled trial, they recruited daily smokers uninterested in quitting smoking with a mean age of 45.1 years and smoking 17.1 (SD = 8.5) cigarettes/day and recruited them either cigarettes that were immediately low-nicotine, cigarettes that had the nicotine level gradually lowered, or continued smoking with normal nicotine content cigarettes. Outcomes yielded no clear evidence if a short-term reduction in biomarkers of tobacco-related harm resulted from switching to very low nicotine cigarettes.