How long do drugs stay in your system?

According to drug use statistics, around 7% of UK adults have taken a Class A drug, with over 18,000 hospitalisations recorded due to drug misuse. The brief high that drugs provide is often, over time, replaced with a tolerance that can lead to a harmful dependency.

If you’ve recently taken drugs, or know someone who has, you might be in need of information about how long that drug will stay in yours, or their, system. In this piece, we’ll provide information on how long various drugs stay in your body and what factors impact that timeframe.

We’ll also provide information on drug addiction, including the signs of drug dependency to look out for, and what longer-term effects drugs can have on the body.

How long will a drug stay in my body?

The table below provides an estimation on how long drugs will typically stay in your system. Bear in mind, depending on a number of factors, these timelines may be different for different people and their individual circumstances.

Note: The information below comes from Drugs and Alcohol Information and Support Ireland, but is only a general guide. Other sources may provide different timeframes.

Timeline for drugs to show in urine

Timeline for drugs to show in blood tests

It should also be noted that, in addition to blood and urine tests, drugs can also be detected in your hair. When drugs become present in your bloodstream, they can make their way to any part of your body, including your hair via hair cells. In this case, drugs can stay in your system for as long as 90 days after consumption.

What affects how long drugs stay in my body?

The information above should only be used as a general guide to how long drugs can stay in your system. This is because a variety of different factors can impact how long drugs stay in your body. Here are a few of the key factors:

Amount consumed and frequency of use

How heavily you use the drug can have a big impact on how long it stays in your system. On a one-use basis, a drug may only be in your system for a short period of time. But extensive use, either in one go or consistently taken over a long period, can lead to higher concentrations of the drug in your body – leading to the drug staying in your body over a much longer period.

General tolerance

If you've built up a tolerance to the drug with regular consumption, it can metabolise more quickly in your body. This leads to a shorter period of time in your system.

Alcohol consumption

If you drink alcohol at the same time as consuming drugs, it can lead to the drug staying in your system for longer.

Weight and metabolism

Your weight can impact how long drugs stay in your system. If you have a higher level of body fat, you’ll generally find that drugs stay in your system for longer. The metabolites (what your body breaks the drugs down into), can accumulate in your fatty tissues, leading to a longer duration in the body.

When should I get help for drug abuse?

Any drug use could have very serious consequences for your health and wellbeing, so if you need help to stop or would like more information, professional help is available. With the right support, you can move past your struggles with substance misuse and lead a much more rewarding, healthier way of life.