One form of nicotine-replacement therapy (NRT) works about as well as another, but a 2019 study in the Cochrane Database of Systematic Reviews found that combining two of these treatments may give you the best chance of kicking the habit.
NRT is designed to help you quit smoking by providing your brain with nicotine, which eases cravings and withdrawal symptoms such as irritability and fuzzy thinking. There are several forms available, including skin patches, chewing gum, lozenges, tablets, and inhalers.
Researchers evaluated 63 clinical trials, which included 41,509 smokers (who usually had smoked at least 15 cigarettes a day), and determined that pairing a skin patch with a fast-acting therapy such as gum or lozenges is the most effective NRT strategy: Combination therapy increased the chances of successfully abstaining from tobacco by 15 to 36 percent over using a single form of NRT.
This analysis also found that higher-dose patches (providing 21 or 25 milligrams of nicotine), and gum or lozenges with 4 milligrams, were more effective than lower-dose products.
Finally, the study found evidence that starting NRT before you actually quit may improve your odds of success, but it’s unclear whether larger doses of nicotine would cause more side effects.