A study by the Massachusetts Department of Public Health found, regardless of cigarette brand, the amount of nicotine delivered to a smoker's lungs had increased significantly since the last research was carried out.
"These findings are significant. This is the first release of information on nicotine yield in more than six years nationally," said the US health department's commissioner Paul Cote.
"We want health care providers to know that smokers are getting more nicotine than in the past and may need additional help in trying to quit," he added.
The data come from reports submitted between 1998 and 2004 by all tobacco companies selling cigarettes in Massachusetts.
The state is one of only three in the US to require such submissions by law.
"Overall, nicotine yields increased 10 per cent from 1998-2004," said a health department statement.
"Smoking is a powerful addiction. Smokers often make multiple attempts to quit before they can successfully stop smoking. Increased nicotine yield may make it harder to quit," associate commissioner Sally Fogerty added.