The short answer
In the best-known study of a month off alcohol, 94 moderate-to-heavy drinkers who stopped for a month saw insulin resistance fall by about 26%, blood pressure by about 6% and weight by 1.5%, while people who kept drinking saw no change. Separate Dry January studies found that participants were still drinking less six months later, even those who did not finish the month.
Key takeaways
- A month off alcohol lowered insulin resistance, blood pressure, weight and two cancer-related growth factors in a UK study of 94 people.
- People who kept drinking over the same month showed none of those changes.
- Six months after Dry January, participants drank less and felt more able to say no to a drink, even if they had slipped during January.
- Very few people drank more afterwards: researchers found little sign of a rebound.
- If you drink heavily every day, stopping suddenly can be dangerous: talk to a doctor before you start.
The one-month study: what changed in the body
The clearest measurements come from a study at University College London, published in BMJ Open in 2018. Researchers followed 94 healthy adults who planned to stop drinking for a month and 47 who planned to carry on. Everyone was a regular drinker: at the start, the group who stopped drank about 258 grams of alcohol a week, which is roughly 32 UK units or 18 US standard drinks. People with known liver disease or alcohol dependence were not included.
After one month without alcohol, the group who stopped showed significant falls in several measurements that matter for long-term health. The researchers checked whether changes in diet, exercise or smoking could explain them, and they could not. The group who kept drinking showed no significant change in any of the same measurements.
| Measurement | Change in the group that stopped | What it is |
|---|---|---|
| Insulin resistance (HOMA score) | down 25.9% | How hard the body has to work to keep blood sugar in range; high values point towards type 2 diabetes risk |
| Systolic blood pressure | down 6.6% | The top number of a blood pressure reading |
| Diastolic blood pressure | down 6.3% | The bottom number of a blood pressure reading |
| Weight | down 1.5% | About 1.2 kg for someone who weighs 80 kg |
| VEGF | down 41.8% | A growth factor the authors linked with cancer risk |
| EGF | down 73.9% | Another cancer-related growth factor |
What happened six months after Dry January
The University of Sussex has followed Dry January participants for several years. In a 2016 study in Health Psychology, 857 British adults answered questions before Dry January, after it and six months later. Taking part was linked with drinking less and with more confidence in turning down a drink six months on. This was true for everyone who took part, whether or not they managed the whole month, although the changes were more likely among people who completed it.
A larger study in 2019, published in Alcohol and Alcoholism in 2020, compared 1,192 Dry January participants with 1,549 adult drinkers who did not try to stop. People who completed Dry January reported better physical health and well-being, more control over their drinking and lower scores on a standard drinking questionnaire (AUDIT-C), in February and again in August. Drinkers who had not taken part showed none of these improvements over the same months.
A common worry is that a month off leads to a binge in February. The 2016 study looked for this "rebound" and found that very few people reported drinking more after their month of abstinence.
Who signs up, and why that matters for the results
The 2020 study found that Dry January participants were not typical drinkers. Compared with the general population, they drank more, had lower well-being and felt less in control of their drinking at the start. In other words, the challenge seems to attract people who have a reason to change, and the benefits were measured in that group.
Both Sussex studies relied on people describing their own drinking and health, and the BMJ Open study compared volunteers who chose to stop with volunteers who chose not to. None of them was a randomised trial. That does not make the findings wrong, but it means you should read them as "what tends to happen to people like this", not as a promise of what will happen to you.
Why there is no honest week-by-week timeline
Many pages promise a precise schedule, such as clearer skin in week two or a set percentage of liver fat gone by day 14. We could not find studies that measured those changes week by week in Dry January participants, so we do not give one. The UCL study measured people at the start and at the end of the month. The Sussex studies asked people at the start, the end and six months later.
What the research does support is simpler. By the end of a month, measurements such as blood pressure and insulin resistance had improved in people who stopped, and many participants felt better and drank less for months afterwards. Your own month will depend on how much you drank before, your health and what else changes in your life.
If you want to see your own month take shape, the Dry January tracker counts your alcohol-free days, and the standard drink calculator helps you work out what your usual week really adds up to.
Benefits the NHS lists for drinking less
Outside the Dry January studies, the NHS describes benefits of cutting down that people may notice soon, including feeling better in the mornings, being less tired during the day, better-looking skin, more energy and help with managing weight. It also lists longer-term benefits, such as lower risk of cancer, diabetes, stroke, dementia and heart, liver and kidney problems, along with better mood and sleep.
These are general benefits of drinking less, not results measured in one-month challenges. They are a good reason to keep some of the change going after January, for example with regular drink-free days, which the NHS also recommends.
Before you start: when a month off needs a doctor first
For most people a dry month is safe. The exception is anyone whose body has become dependent on alcohol. The NHS warns that it can be very dangerous to stop drinking suddenly if you are dependent on alcohol, and that if you get withdrawal symptoms, you should get medical help before you try to stop.
According to the NHS, withdrawal symptoms can include anxiety, difficulty sleeping, feeling sick, a racing heartbeat, sweating and shaking, and in severe cases hallucinations, confusion or seizures. They usually begin within 6 to 12 hours of the last drink. If that sounds familiar, a doctor can help you cut down or stop safely, and the tracker will still be here when you are ready.
Common questions
How much weight do you lose in Dry January?
In the UCL study of moderate-to-heavy drinkers, people who stopped for a month lost 1.5% of their body weight on average, about 1.2 kg for someone weighing 80 kg. Results varied between people, and the study did not look at people who drank lightly before January.
Do the benefits of Dry January last?
The Sussex studies suggest some do. Six months later, participants were drinking less and felt more able to refuse a drink, and completers reported better well-being in August. The physical measurements in the UCL study were only taken at the end of the month, so we do not know how long those lasted.
Is it worth doing Dry January if I might not finish it?
The 2016 Sussex study found that taking part was linked with drinking less six months later even among people who did not complete the month, although the changes were more likely in those who did. A month with a few slips still appears better than no attempt at all.
Does Dry January make people drink more in February?
Researchers looked for this rebound effect in 857 participants and found that very few reported drinking more after their month off. Most drank the same or less in the six months that followed, according to the 2016 study in Health Psychology.
Who should not stop drinking suddenly?
Anyone who is dependent on alcohol, for example someone who gets shaky, sweaty or anxious when they go without a drink. The NHS says stopping suddenly can be very dangerous in that case and advises getting medical help before you try to stop.
When to get help
This site offers self-help tools and information, not medical advice. Talk to a doctor, or call one of the lines below, if:
- you feel shaky, sweaty, sick or anxious when you haven't had a drink;
- you find it hard to stop once you start, or you want to cut down and can't;
- drinking is causing problems with your health, work or the people close to you.
Before you stop: It can be very dangerous to stop drinking suddenly if you are dependent on alcohol. If you get withdrawal symptoms, get medical help before you try to stop drinking.
Free, confidential helplines
- United States:SAMHSA National Helpline1-800-662-HELP (4357)Treatment referral and information, 24/7.
- United States:988 Suicide & Crisis LifelineCall or text 988Free and confidential support for people in distress, 24/7.
- United Kingdom:Drinkline0300 123 1110The national alcohol helpline, free and in complete confidence. Weekdays 9am to 8pm, weekends 11am to 4pm.
In an emergency, call your local emergency number.
Sources
- Mehta G, Macdonald S, Cronberg A, et al. (2018). Short-term abstinence from alcohol and changes in cardiovascular risk factors, liver function tests and cancer-related growth factors: a prospective observational study. BMJ Open, 8(5), e020673. PMID 29730627
- de Visser RO, Robinson E, Bond R. (2016). Voluntary temporary abstinence from alcohol during "Dry January" and subsequent alcohol use. Health Psychology, 35(3), 281–289. PMID 26690637
- de Visser RO, Piper R. (2020). Short- and Longer-Term Benefits of Temporary Alcohol Abstinence During 'Dry January' Are Not Also Observed Among Adult Drinkers in the General Population: Prospective Cohort Study. Alcohol and Alcoholism, 55(4), 433–438. PMID 32391879
- Tips on cutting down on alcohol. NHS. nhs.uk
- Alcohol-use disorder. NHS. nhs.uk
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