The New Year’s Eve party hangover has finally lifted.

For many, the end of the post-holiday haze means kicking off the new year with a “Dry January," when a person goes one month without any alcohol.

The idea of becoming a 30-day teetotaler to start the year has been around for decades.

It’s become so popular that one United Kingdom charity called Alcohol Concern has turned it into an annual campaign.

But what can going alcohol-free do for the body?

There aren’t extensive studies on the long-term effects of Dry January, but there has been limited medical research on how people fare during that month and in the months that follow.

One study following 857 British adults found some people did report consuming less alcohol six months after taking part in Dry January.

Importantly, there didn’t appear to be a “rebound” effect, where after one month of abstaining from alcohol, people increased their drinking in the following months.

One of the study co-authors did work at Alcohol Concern, which promotes the annual Dry January campaign.

The short-term gains

Dr. Roy Buchinsky, director of wellness at University Hospitals Cleveland Medical Center, said it’s clear that even short-term abstinence can improve health.

“Certainly in the short term it can help with regards to both physical as well as mental functions,” he told Healthline.

It can help “from a physical standpoint, obviously, things like liver regeneration, allowing our liver to take a break from the alcohol,” he added.

Buchinsky also said that alcohol can disrupt sleep patterns, so giving up booze can help some people get a better night’s rest.

He added that abstaining from drinking means people are limiting the “liquid calories” associated with alcohol, something that could help people anxious to lose those holiday pounds.

Since alcohol is a depressant, it can also affect people’s mental states.

“It can cause a little bit of the winter blues, so by abstaining from alcohol, it certainly might help one in terms of one’s emotional outlook as well,” he said.

Are there long-term benefits?

Buchinsky said in the long run it’s not clear a dry January can provide a significant boost to a person’s health, especially if they go back to drinking in February.

However, he said the practice could provide people the opportunity to pay attention to how much they drink and when they drink.

“Dry January is a good concept because it makes us more mindful,” he said.

Buchinsky said it’s possible that for some people who overindulged during the holiday season, reducing the number of drinks they consume can help them reset their drinking habits for the year.

“I like to say, as goes January, so goes the rest of the year,” he said. “I think it comes down to more balance, doing things in balance, rather than going overboard.”

Dr. Scott Krakower, assistant unit chief of psychiatry at Zucker Hillside Hospital in New York, said there’s no clear data if a month of no drinking is helpful or harmful in the long run for behavioral changes.

Krakower said he’s concerned that some people may return to drinking with vigor after one month as a teetotaler.

“I’m kind of concerned about that reciprocal effect that could happen from the all or none response to the drinking,” he told Healthline.

Krakower said he’d be concerned that these extremes don’t help people make long-term changes in their drinking behavior.

“One way you could go is that, ‘I’m reshaping myself so I’m moving forward,’” he said. “The other way is, ‘I was able to withhold the drinking for so long and now I can reward myself with more drinking as a celebratory thing come February.’”