Quit biting your fingernails. Stop hitting the snooze button every morning (and rushing to get ready for work). Cut fast food or soda out of your diet.

It doesn’t matter who you are—everyone has at least a few habits they’d like to leave behind in favor of healthier or more productive behaviors. But wanting to break a bad habit isn’t enough. Actually breaking a bad habit—and adopting new, healthier behaviors in its place...like taking a multivitamin—requires more than just a desire to do better.

So how, exactly, do you leave old habits behind for newer, better behaviors?

How habits work

Before you can understand how to break bad habits, it’s important to first understand how habits work. “Every habit follows roughly the same psychological pattern, so if a person wrests control of the pattern, then they can break from their habit loop,” explains Dr. Brian Wind Ph.D., Clinical Psychologist, adjunct professor at Vanderbilt University, and Chief Clinical Officer at addiction treatment center JourneyPure.

The habit loop is made up of three different components: the cue, the routine, and the reward. “Every habit starts with the cue, which precedes the urge to engage in a specific behavior: [for example] it’s noon, therefore my stomach growls,” says Wind. “Then we move on to the routine, or the behavior that we’d like to change: walk to the coffee shop. Next comes reward, the satisfaction of the craving, like buying and eating a cookie.”

When you first engage in the cue-routine-reward cycle, it’s new to the brain—and because it’s new, it engages the prefrontal cortex, the area of the brain responsible for decision making. But with time and repetition, the cycle will start engaging your basal ganglia (1), the area of the brain responsible for instinctual behaviors.

Once that happens, the three-part cycle becomes an automatic response—and a habit is born.*

How to break a bad habit

If you want to break a bad habit, you need to interrupt the cue-routine-reward cycle and essentially reprogram your brain so the behaviors are no longer habitual.

According to experts, one of the best ways to do this is by replacing your bad habit with a more constructive one. Wise recommends examining your bad habits, writing them down, and then coming up with a new, better habit to replace one of the habits you’re trying to kick.

“If you want to break a long-standing habit, first figure out when and why you engage in the habitual behavior,” says Wind. “Next, write it down, so that these realizations sink in. Finally, replace that unhealthy or otherwise negative behavior with something positive or less harmful.”

So, for example, let’s say your habit loop is feeling stressed out (cue), walking to the kitchen (routine), and pouring and drinking a glass of wine (reward). A way to break the habit might be replacing the wine with a hot, soothing tea; that way, when you feel stressed and walk to the kitchen, there’s a different reward waiting.

Kicking a bad habit can also be easier if you have a strong why: for example, if you consider yourself a health-conscious person, it may be easier to let go of a junk food habit than it would be if you were trying to do it for external reasons (like someone telling you junk food is bad for you or that you should lose weight).

“People who want to kick their habit for reasons aligned with their own values will change their behavior much faster than people who are doing it for external reasons,” says Wind.*

How long does it take to break a habit?

Here's the truth: There is no magic number. The time frame for breaking bad habits depends on a few factors, including the nature of the habit you're trying to break.

In a 2009 study published in the European Journal of Social Psychology (2), researchers tracked 96 people over a 12-week period to see how long it took them to establish a new habit. On average, it took 66 days to form a new habit. But the individual results varied widely from the average time, with some participants establishing a new habit in as little as 18 days—and others taking as long as 254 days.

The reason for such a wide range of numbers? The amount of time it takes you to break a bad habit depends on a variety of factors. “[How long it takes to break a bad habit] depends on the person, the circumstances, and the habits themselves,” says Wind. “It’s easier to get used to drinking a glass of water each morning than it is to go on a four-mile run every day after work.”

Basically, the best thing you can do is just keep moving forward. Make your new behavior part of your daily routine. The more you practice your new behavior, the more automatic it will feel—until at finally becomes a new habit.*

References

1. Yin, HH. 2006, June 7. The role of the basal ganglia in habit formation. Nat Rev Neuroscience. (6):464-76.
2. Lally, P. 2009, July 16. How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology.