Dry January has become an annual trend in the past several years, prompting many to abstain from alcohol for the inaugural month of the year. But does it work?

Experts say it’s great for some to cut down their alcohol intake after one of the most celebratory times of the year. It reduces calories, improves sleep and brings an awareness of drinking habits. But for others, it actually could be dangerous. Here are five things to know about Dry January.

1. Its history.

The British-based group Alcohol Concern, now named Alcohol Change UK, started the Dry January challenge in 2013. In its first year, 4,000 people took part, according to the group, and the hashtagable trend has grown since then. The group’s tracking shows that while 100,000 people signed up on the website in January 2018, millions actually participated.

“Dry January offers a ready-made response to anyone who tries to pressure us to drink,” Alcohol Change UK CEO Richard Piper said in a statement. “Strong evidence tells us that signing up for Dry January helps people — even heavy drinkers — to drink more healthily all year round.”

2. It’s not for everyone.

Experts warn that it’s not a one-size fits all approach. Especially with heavy drinkers, and even with some moderate drinkers, it can backfire.

“How helpful Dry January is may vary from person to person,” said Mark Zissman, a psychologist and clinical director at Illinois-based Gateway Foundation treatment centers.

Zissman points to dangers facing heavy drinkers who stop cold turkey without professional supervision. “People can actually die from going through withdrawal,” he said. “People forget that.”

As for moderate drinkers, they have to make sure that after taking January off from alcohol, they don’t compensate by ushering in February with even heavier alcohol use.

3. Dry January isn’t treatment.

Zissman recommended that heavy drinkers think about why they might want to quit drinking for a month: Is there an addiction? If so, Zissman said, the approach should go beyond a January challenge.

He suggested using the acronym CAGE as a self-assessment tool for alcohol-use disorder. C stands for cutdown attempts in the past. A stands for annoyed: Are you annoyed by others commenting on your drinking? G is for guilt felt after drinking. And E is eye-opener: Do you need a drink in the morning or notice other physical dependence?

4. Who benefits?

Zissman said that Dry January can be a wake-up call. “Maybe they find they rely on [alcohol] a little bit too much, but they don’t necessarily have a problem,” he said.

He said more research is needed, but there’s some that shows the Dry January can lead to drinking less for several months afterward.

Alcohol Change UK cites research that shows 72% of Dry January participants are engaging in “less risky” drinking six months after Dry January.

5. Dry-ish January also becoming popular.

While it’s not unusual for bars to capitalize on the Dry January trend, offering mocktails as an alternative to patrons, there’s another mechanism for mindful drinking: Dry-ish January, according to Jennifer Contraveos, Chicago-based senior portfolio ambassador for Bacardi USA.

“It’s certainly a trend we’re not only seeing at the start of any new year,” she said. “In many facets, people are more conscious of what we are putting into our bodies” year-round.

Recognizing the trend, bartenders are offering recipes that use lower-alcohol liquors or other substitutions to make for a good “dry-ish” drink, Contraveos said.

That could mean a shot of vermouth in a drink instead of whiskey, mixing up the ratios in drink recipes or simply smaller cocktails, she said.