Do you think it takes 21 days to form a habit? Science says again

A popular piece of self-help folklore might be more complicated than we thought. New research reveals that it takes much longer than a month to form a new habit.

Scientists from the University of South Australia conducted the study, a review of existing evidence on habit formation. They found that habits usually begin to form after about two months. For some unlucky people, however, it could even take up to a year.

With 2025 still fresh out of the stove, there are undoubtedly plenty of people who have started a new exercise regime or other healthy lifestyle change in recent weeks. And you may have heard that it takes 21 days for a routine to start becoming ingrained in our lives; Others might have heard 18 or 28 days instead. However, some studies have suggested that this supposed rule is not that simple.

To get to the root of this topic, researchers from the University of South Australia analyzed data from 20 studies that examined the formation of healthy habits like routine exercise, drinking water or flossing dental; These studies collectively involved more than 2,500 participants. One specific question the studies sought to answer was how long it takes for a habit to achieve something called “automaticity” — the point at which people perform it regularly and without much thought.

The researchers found that habits were formed on average from 106 to 154 days. The median length of a habit form was about 59-66 days (the median is the middle of a group of numbers in case you forgot). That said, the study found plenty of outliers. The shortest habit adoption duration was four days, while the longest was a whopping 335 days.

“Emerging evidence on health-related habit formation indicates that while habits can begin to form in about two months, the time required varies considerably among individuals,” the researchers wrote in their paper, published last month in the magazine Health care.

The researchers say they were only able to find a relatively small number of studies to analyze, and most of the included studies were rated at high risk of potential bias. More and better studies are therefore needed to better understand the duration and other aspects of habit formation, they say.

At the same time, the researchers believe their findings should reassure people who feel discouraged that they haven’t adapted to their new routine or habit as quickly as they would expect from conventional wisdom. They also note that there are science-backed ways to improve the chances that a lifestyle change will stick.

“When trying to establish a new healthy habit, success can be influenced by a range of things, including how often we undertake the new activity, the timing of the practice, and whether or not we enjoy it,” she said. said lead study researcher Ben Singh A statement from the university. “If you add a new practice to your morning routine, data shows you’re more likely to achieve it. You’re also more likely to stick with a new habit if you enjoy it.

I’m personally very encouraged by this advice, considering my new healthy habit this year of rubbing my face in my cat’s belly every morning.