How Long Does Alcohol Stay in Your System?

When we drink, alcohol has to travel through our bodies, just like any other substance. This means that it stays in our system for longer than we may realise. This is often why people suggest waiting a certain amount of time after drinking to drive, for example – even if you ‘feel’ sober. We can’t rely on the fact that alcohol has left our system because we no longer notice the acute effects of drinking.

To stay safe – and to follow legal guidelines for work, driving, breastfeeding and other regulated activities – it is crucial to know how long alcohol stays in our bodies. This can help us to make an informed decision on when to drink and when it is best to abstain, as well as help us understand what an appropriate amount of alcohol is each time we drink.

Processing alcohol

When you drink alcohol, you will probably find that you feel its effects pretty swiftly. When we consume alcohol, like any other beverage, it enters our stomachs. It then gets absorbed into our bloodstream via our stomach lining and starts to move around our body through our blood. In this way, alcohol reaches our brain. This process tends to take around 10 minutes.

The alcohol levels in our blood peak at around 30 to 45 minutes before starting to decline again, but it can stay in our body for hours after drinking.

Detecting alcohol

It is possible to identify the presence of different substances through a series of tests. There are several ways that alcohol can be detected in our bodies using different bodily materials and devices. These tests identify alcohol by checking:

• The blood
• The breath
• The hair
• The saliva
• The urine

These tests tend to work by searching for the presence of actual alcohol or alcohol metabolites. Alcohol metabolites are chemical compounds that are made whilst our bodies process and digest alcohol. These metabolites can be found in the various bodily materials listed above.

Detection windows

Each test for alcohol has a different ‘detection window.’ This means that the length of time that alcohol can be identified in each bodily material varies.

Alcohol can be identified in the blood for up to 12 hours after your last drink.

On the breath, alcohol can be detected anywhere between 12 and 24 hours after your last drink.

In hair, alcohol can be identified for up to 90 days. This makes the alcohol detection window of hair the largest amongst all the screening types.

In saliva, tests can detect alcohol for up to 12 hours after your last drink.

Tests on urine can detect alcohol for between 12 and 24 hours after your last drink.

It can be useful to know these timings not only to know when alcohol is detected but also to make informed decisions on when to engage in specific activities. For example, alcohol can be present in breast milk for some time after drinking. For this reason, the NHS recommend waiting at least 2 hours after having a drink before feeding’ and warns that ‘regularly drinking above the recommended limits can be harmful for you and your baby.’

Mitigating factors

Whilst these are the general timelines of detection windows, in reality they can change somewhat. The windows given above are averages. This means that for some people, alcohol can be detected in their system for slightly less or slightly less time.

The biggest factor is that heavy drinking – such as back-to-back drinking sessions or periods of binge drinking – can extend the detection window. This means that alcohol can be detected in your system for longer than the timelines stated above. For example, one study found that after a period of excessive drinking, alcohol could be detected in urine for up to five days.

Other factors that influence how fast our bodies process alcohol (and therefore how long it stays in our system) include:

• Body weight
• Age
• Gender
• Type of alcohol consumed
• If other drugs have been used at the same time
• If you ate prior to (or whilst) drinking
• If you take medications
• Your metabolism
• Your liver health
• Your general health

When are alcohol tests used?

There are various situations when an alcohol test may be needed. These often fall into two main categories:

1. Tests associated with work
2. Tests associated with legal investigations

These tests are usually used when alcohol abuse would risk engagement with unsafe behaviours.

Tests at work

Testing at work is often used when drinking alcohol could compromise health and safety. UK Drug Testing describe these as ‘safety-critical employment roles.’

These types of tests, then, are likely to occur in occupations that involve:

• Driving
• Operating heavy machinery
• Working at heights

These tests are used to mitigate instances where ‘the misuse of drugs or alcohol could have disastrous effects for the employee, colleagues, members of the public and the environment.’

If you are asked to provide a sample for an alcohol screening, you are allowed to deny this request. However, under employment law, this denial can lead to disciplinary consequences. In some cases, providing a sample may be obliged under employment contracts.

Tests for legal reasons

Alcohol screenings are often used by the police in law enforcement contexts. One of the most common instances of this is in connection with road traffic collisions. This is perhaps no surprise given that ‘alcohol impairment remains the single greatest contributing factor to fatal traffic crashes.’

Police officers can request a breath alcohol test in instances where ‘they reasonably believe a person was driving, attempting to drive or in charge of a vehicle at the time of an accident on a road or other public place.’

Depending on the situation, a positive breath test can lead to legal consequences. This can include:

• Imprisonment
• A ban from driving
• A fine

Outside of the legal consequences, there can be other social repercussions. These include:

• An increase to car insurance
• Your employer being informed of the incident (if your job includes driving)
• Difficulty troubling to certain countries

Making wise choices

When it comes to alcohol, the best way to keep yourself and others safe is by making wise choices. Part of doing this is by being mindful about how alcohol tends to affect you. You can make informed decisions about drinking by planning alcohol-based activities well, keeping tabs on how much you are drinking (in quantity and percentage) and ensuring you eat well beforehand. Being thoughtful about the impact of your drinking is especially important in busy times of year like the festive season, when we may find that we easily become pressured to drink more, to stay longer, and to give people lifts. But it is essential to remain wise and responsible when drinking.

Support for excessive drinking

If you feel that you are at a stage where you are struggling to make wise decisions around drinking, then it may be time to access help. Support for drinking problems comes in all forms – at UKAT, there is an appropriate route to recovery for everybody.  Contact us today to seek judgement-free, specialist advice from a member of our consultation and admissions team.