Studies show that when trying to quit smoking without help, the chance of success is only 5 percent. Researchers say what smokers need most is a comprehensive quit plan, which should start with counseling.

Dialing 1-800-QUIT-NOW connects smokers to state-funded help lines, where each caller gets personalized help.

The initial call can take 30 minutes, guided by a trained counselor or "quit coach." The counselor often calls back the smoker every few weeks, offering help and support.

Research shows that smokers who use telephone counseling when they're about to quit are two to three times more likely to succeed than those who don't get this help.

Is Quitting Cold Turkey a Mistake?

Many help lines send out quit smoking guides on coping skills, dealing with stress, withdrawal symptoms, and (perhaps most important) the use of medicines. Many smokers mistakenly try to avoid using nicotine replacement products.

"They think that nicotine causes cancer, which it doesn't," said Dr. Nancy Rigotti of the Tobacco Research and Treatment Center at Massachusetts General Hospital in Boston. "There's a lot of misunderstanding out there. Nicotine replacement products have been shown to be both safe and effective. They roughly double the chance of quitting."

Nicotine patches, applied once a day, provide a slow, steady dose of nicotine into the bloodstream. But tobacco cravings can erupt at any time, so smokers are encouraged to carry backup, such as nicotine gum, nicotine lozenges or a nicotine inhaler. Zyban, a prescription antidepressant, can also be added to further reduce withdrawal symptoms.

"We really can mix-and-match these products, and I think that's where the future in our field is," said Rigotti.

Researchers emphasize these products must be used not just for a few weeks, but often for several months — or longer. Even then, many people struggle. So, once again, they call the quit line.

"I hate the tyranny of it, that I'm a slave to it," one caller said. "It drives me crazy. I can be fine, then 'boom' — all of a sudden I have to have a smoke."

"A lot of people struggle with this," the coach replied. "They go back and forth with their success. So let's see how we can deal with these mood changes."

Researchers say smokers today have more tools to help them quit than ever before. If only they would use them.

ABC News' John McKenzie filed this report for "World News Tonight."