Every January, a lot of people take a month off alcohol, and sooner or later the question comes up: is a month off actually doing anything for my liver, and would a blood test show it?

The honest answer is more interesting than either “a month resets everything” or “it makes no difference”. This guide covers what alcohol does to the liver, what a month without it can reasonably be expected to change, and what liver blood tests can and cannot tell you. At WMG Health, our private blood testing clinic at 134 Harley Street, London, every result is reviewed by a GMC-registered doctor.

One thing first. If you drink heavily every day, or you get shaky, sweaty, anxious or sick when you go without a drink, do not stop suddenly without medical advice. The NHS warns that alcohol withdrawal can be dangerous for people who are physically dependent. Speak to your GP, who can help you cut down safely. The NHS website also lists free alcohol support services.

What alcohol does to the liver

Your liver processes almost all the alcohol you drink. When you drink more than it can comfortably handle, the NHS describes three broad stages of alcohol-related liver disease:

  1. Alcohol-related fatty liver. Fat builds up in the liver. There are often no symptoms, and the NHS says the liver can usually recover if you stop drinking.
  2. Alcohol-related hepatitis. The liver is swollen and damaged, and symptoms are likely. The liver may recover from some of the damage.
  3. Cirrhosis. The liver is badly damaged and scarred, and the NHS says this damage cannot usually be reversed.

The most important thing to understand is that alcohol-related liver disease does not always cause symptoms in the early stages. Early signs, when they appear, can be vague, such as tiredness, reduced appetite or discomfort in the upper right of the tummy. That is part of why the question “would a blood test show it?” matters, and also why the answer has limits.

The UK Chief Medical Officers’ low-risk guidance, which the NHS uses, is to drink no more than 14 units a week on a regular basis, spread over three or more days if you regularly drink as much as 14 units. As a rough guide, the NHS says 14 units is equivalent to 6 pints of average-strength beer or 10 small glasses of lower-strength wine across the whole week.

What a month off can, and cannot, do

Here is what can reasonably be said, without overselling it.

What it can do:

  • Give the liver a break from processing alcohol. The NHS describes alcohol-related fatty liver, the earliest stage, as something the liver can usually recover from if you stop drinking.
  • Let some blood markers settle. GGT is one of the liver enzymes that can be raised by excess alcohol, and it may stay raised for a few weeks after a period of drinking before coming down. A month off may be long enough for a change to show, though this varies from person to person.
  • Show you what your drinking habits actually are. For many people the most useful thing about a month off is noticing how hard or easy it is. If you find it hard, that is worth talking to your GP about.

What it cannot do:

  • It does not undo scarring. Cirrhosis is generally permanent. Stopping drinking can prevent further damage and improve the outlook, but a month is not a treatment for established liver disease.
  • It does not need a “detox”. Your liver clears alcohol on its own. The NHS describes stopping drinking, with medical support where needed, as the treatment for alcohol-related liver disease, not detox products.
  • It does not last if February is a rebound. Any benefit depends on what you do for the other eleven months. A month off followed by a return to heavy drinking does not bank anything.

What liver blood tests actually show

A liver function test (LFT) is a group of blood tests, rather than a single one. The exact components vary between laboratories, but a standard LFT usually includes enzymes that leak out of damaged liver cells, markers of bile flow, and measures of how well the liver is making proteins. The ones people most often ask about are:

  • ALT (alanine transaminase). An enzyme found mainly in liver cells, so a raised ALT points towards the liver. The British Society of Gastroenterology (BSG) says most adults with abnormal liver blood tests turn out to have fatty liver disease unrelated to alcohol (NAFLD) or alcohol-related liver disease.
  • AST (aspartate transaminase). Also found in muscle, so it is read alongside ALT. The BSG says an AST to ALT ratio above 1 indicates advanced scarring (fibrosis or cirrhosis) in adults with abnormal liver tests, so the two are always read together by a clinician.
  • GGT (gamma-GT). The BSG says it is most commonly raised by obesity or excess alcohol, and can also be raised by some medicines. It has low specificity for liver disease, and raised GGT together with raised ALP points towards a bile-flow (cholestatic) problem.

Other markers in a routine blood panel can add clues:

  • Full blood count. NHS haematology guidance lists alcohol among the commonest causes of larger-than-usual red blood cells, which shows up as a raised MCV.
  • Ferritin. The BSG notes that a raised ferritin on its own is commonly seen with alcohol excess and fatty liver, and that it does not necessarily mean iron overload.
  • Folate. The NHS lists regular alcohol misuse as a cause of low folate.

What liver blood tests cannot show

This is the part that is easy to get wrong in both directions.

  • Normal liver tests do not rule out liver disease. The BSG says normal liver blood tests do not rule out advanced fibrosis and cirrhosis, and that liver enzymes are a poor guide to scarring in alcohol-related liver disease. A clean LFT is reassuring, but it is not a clean bill of health if you have been drinking heavily for years.
  • Abnormal liver tests do not automatically mean alcohol. Mildly raised enzymes are common and often reflect fatty liver linked to weight and blood sugar, or medication. What happens next depends on the pattern, your history and your doctor’s judgement.
  • A blood test cannot tell you whether you drink too much. That is a conversation, not a lab value.
  • Blood tests do not measure scarring directly. For people drinking at harmful levels, the BSG recommends assessing the risk of scarring with a clinical assessment and elastography (FibroScan, a type of ultrasound scan that measures liver stiffness). That is arranged through your GP or a liver specialist.

Fatty liver is not only about alcohol. It is also linked with carrying extra weight and with blood sugar, which is why raised liver enzymes and a raised HbA1c can turn up together.

Should you test before and after Dry January?

It can be a useful way to see your own numbers change, as long as you go in with the right expectations.

  • A test at the start of January reflects December. Because GGT in particular can stay raised for a few weeks after drinking, a baseline taken straight after the festive season may show your “recent heavy” picture, not your “usual” one. That is still informative.
  • A repeat towards the end of the month may show a change in GGT. It will not show anything about scarring, and a normal result is not a reason to go back to drinking above the guidelines.
  • Tell the doctor reviewing your results how much you have been drinking, including any recent heavy sessions and any strenuous exercise, so the numbers can be read in context.

If you want to understand the wider picture of how the festive season affects your blood results, our guide to what your body actually needs after Christmas covers iron, vitamin D, B12, liver and blood sugar together.

When to see your GP or get urgent help

See your GP if you are worried about how much you drink, if you find it hard to cut down, or if you have ongoing tiredness, reduced appetite or tummy discomfort. The NHS lists yellowing of the skin or whites of the eyes (jaundice), a high temperature, swelling of the tummy from fluid and swollen legs as warning signs of worsening liver damage, so get medical advice promptly if you notice them.

Call 999 or go to A&E if you are worried that alcohol may be affecting your liver and you vomit blood, your poo is black and looks sticky, you have abdominal pain or difficulty breathing, or you feel suddenly confused or dizzy or have difficulty staying awake.

If you are concerned about your drinking, your GP is a good place to start and can offer support and refer you to local alcohol services. Drinkline, the free national alcohol helpline, is on 0300 123 1110 (weekdays 9am to 8pm, weekends 11am to 4pm), according to the NHS.

Getting tested at WMG Health

Liver function tests (LFTs) are included in our General Wellness panel (£279). The same panel covers the other markers in this guide: a full blood count (with MCV), iron studies including ferritin, and folate, together with vitamin D and B12, thyroid function, kidney function, a lipid profile (cholesterol), HbA1c, CRP and ESR, and zinc. That means one draw shows your liver enzymes alongside the blood sugar and cholesterol results that often travel with fatty liver.

If you want liver markers on their own, or a specific enzyme such as AST or GGT that a doctor has asked about, you can arrange it through a custom panel, where a clinician confirms the price in writing before you book. Our New Year health check guide explains how to choose a panel without paying for markers you do not need.

Results are released as each marker is reviewed by a GMC-registered doctor, with the expected timeframe confirmed at booking. Private testing is a way to see your numbers, not a replacement for your GP: if anything needs follow-up, we will tell you and recommend that you share the results with them.

Common questions

Will a month off alcohol reverse liver damage? It depends on the stage. The NHS says the liver can usually recover from alcohol-related fatty liver if you stop drinking, and a month is a good start. Cirrhosis (scarring) usually cannot be reversed. What matters most is your drinking over the long term, not one month.

Can a liver blood test tell if I drink too much? Not reliably on its own. Markers such as GGT and a raised MCV can be raised by regular heavy drinking, but they also rise for other reasons, and normal results do not prove your drinking is low-risk.

Do I need to fast for a liver function test? No fasting is needed for ALT, AST or GGT on their own, but the General Wellness panel as a whole needs a fast of at least 12 hours beforehand, with water only, and not much longer than 12 hours. Avoid alcohol for 24 to 48 hours and strenuous exercise for 48 hours beforehand; exercise can also raise AST from muscle.

Should I stop drinking before a liver test? Follow the preparation instructions for your panel, which include avoiding alcohol for 24 to 48 hours beforehand. Beyond that, there is no need to change your habits for the test: the aim is to see your usual picture, so tell the reviewing doctor about any recent heavy sessions.

My ALT is slightly raised but I hardly drink. Why? The BSG says most adults with abnormal liver blood tests turn out to have fatty liver disease unrelated to alcohol or alcohol-related liver disease, and fatty liver is often linked to weight and blood sugar. Medicines can also raise liver enzymes. Your GP can look at the pattern and decide what to do next.

  • Raised Liver Enzymes: Causes and Next Steps: what a raised liver enzyme can mean and what happens next.
  • Private Blood Test Cost in London: Price Guide: what each panel costs and what drives the price.
  • How Often Should You Have a Health Check?: age-by-age guidance on health checks and blood tests.

Sources

  • NHS: Alcohol-related liver disease (ARLD): overview, diagnosis and treatment. nhs.uk
  • NHS: Calculating alcohol units (the UK low-risk drinking guideline). nhs.uk
  • NHS: Alcohol support. nhs.uk
  • NHS: Vitamin B12 or folate deficiency anaemia (causes). nhs.uk
  • British Society of Gastroenterology: Guidelines on the management of abnormal liver blood tests (Newsome et al, Gut 2018). gut.bmj.com
  • NHS haematology guidance on macrocytosis (for example Greater Manchester, Macrocytosis in adult patients). nwknowledgenow.nhs.uk

This article is for general information only and does not constitute clinical advice. If you are worried about your drinking or your liver, speak to your GP.