How Long Does Crack Stay in Your System?

A person holding a small baggies of powder crack cocaine

Crack is a highly potent form of smokable cocaine that has a significant risk for addiction. This article will provide information about crack, how long it affects the body, how long it stays in the system, and factors that affect how it is metabolized.

Duration of Effects of Crack

Smoking crack causes a sudden rush of euphoria that subsides within 5–15 minutes. Physiological effects, including elevated heart rate, restlessness, anxiety and depression, may last for an hour or more. After the rush is over, users often experience intense cravings and display obsessive drug-seeking behavior. 

Crack Half-Life

The half-life of crack is less than 1 hour, meaning that it is undetectable within 5 hours. However, crack has two primary metabolic byproducts: 

  • Benzoylecgonine: also a byproduct of cocaine metabolism, it has a half-life of 12 hours
  • Methylecgonidine: unique to crack it has a half-life in blood of 18–21 minutes. Methylecgonidine is further processed into ecgonidine, which has a half-life of about 2 hours and can be detected for 10 hours after light use. With heavy use, ecgonidine may be detected for 48 hours or more. Some data suggests that routine heavy use can increase detection windows of these byproducts. In this case, ecgonidine may be detectable for weeks

How Long will Crack Show in Drug Test?

Crack is generally cleared from the system within a few days after use, but heavy or prolonged use results in longer windows of detection. In extreme cases, crack drug tests can detect metabolites for weeks after last use. 


Light or moderate use of crack will cause urine tests to be positive for 2–3 days. Chronic, heavy use will extend this time window substantially. 


Blood tests will generally be positive for up to 24 hours after using, but this time will be extended if someone has used crack heavily or for a long time.


Saliva is essentially filtered blood without the red blood cells, so its detection window is similar to blood. Saliva drug tests can detect crack or its metabolites for 24–48 hours.


Hair can deliver a positive crack screen for 90 or more days after last use. The reason for this relates to how crack travels through the bloodstream. Hair follicles need oxygen and other nutrients to make hair, so blood capillaries are in close proximity to hair follicles. 

If someone stops using crack, the part of the hair that incorporated the crack will grow out. Thus, if someone smoked crack a couple of months ago, cutting their hair short may prevent a positive hair drug test.

Factors Affecting How Long Crack Stays in Your System

Factors that affect how long crack stays in the system include:

  • Liver function: Because the liver metabolizes crack, poor liver function will result in a buildup of crack or its byproduct, methylecgonidine
  • Length of use: Prolonged use will result in a higher concentration of crack that will take longer to metabolize
  • Amount used: The more crack that is smoked, the longer it will remain in the system
  • Food and water intake: A healthy diet and lots of water may promote clearance of crack from the system
  • Metabolism: Individuals with faster metabolisms will clear crack sooner than others. Similarly, people with high fat content will have positive drug tests for a longer time than people with low fat content

False Positives for Crack

Cocaine and crack drug tests are generally very reliable, but rare exceptions do occur. Currently, most routine drug tests only evaluate methylecgonidine or ecgonidine, but some tests measure both. Measuring both metabolic byproducts can minimize the risk of a false positive

How Crack Is Broken Down in the Body

When crack is inhaled into the lungs, it is taken up by alveoli. Alveoli are normally responsible for expelling carbon dioxide and replacing it with oxygen. The lungs have an incredibly large surface area with a vast network of tiny blood vessels called capillaries. The capillaries carry oxygen (and crack) into blood vessels that travel to the heart. 

From there, crack travels to every organ in the body, including the brain. In the brain, crack has a profound effect on dopamine and the “reward pathway,” which causes its addictive nature. Crack travels throughout the body in a matter of seconds, which is why crack has such a rapid onset of action. 

When crack reaches the liver, it is metabolized into benzoylecgonine and methylecgonidine. Methylecgonidine is further processed into ecgonidine. Most of these byproducts will be excreted via urine and feces, but some of them will be recirculated through the blood. When large amounts of crack are used, more byproducts need to be excreted or recirculated, extending the time frame for positive drug tests.

How to Get Crack Out of Your System

The most reliable way to get crack out of your system is to stop using it immediately and wait for it to clear from your system. There is no magic bullet, but it may help to drink lots of water, do aerobic exercise and eat a healthy diet. Consuming alcohol will actually slow down clearance of crack from your body, so avoiding alcohol may help as well.

Key Points: How Long Does Crack Stay in Your System?

The biggest points to remember about crack metabolization include:

  • Crack is smoked for its almost immediate rush, and the effects last for up to 15 minutes
  • Crack is notoriously addictive. Once the rush fades, many users experience intense cravings that promote compulsive drug-seeking behavior
  • Crack or its metabolites are usually detectable in blood for 24 hours, in urine for up to 3 days and in hair for several months
  • Heavy, long-term crack use can increase the window of detection substantially
  • Crack itself has a very short half-life, but the liver breaks it down into metabolites with longer half-lives. Most drug tests are actually testing for crack metabolites
  • Despite claims that crack detox kits are magic bullets, the only way to get crack out of your system is to stop using it and wait. However, it may help to eliminate alcohol, eat right, drink lots of water and do aerobic exercise

If you or a loved one is using crack, The Recovery Village can help. Our multidisciplinary team of experts can provide medical and mental health care that can help you begin the road to recovery. Contact us today to learn more about treatment plans and programs that can work well for you.

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Medical Disclaimer: The Recovery Village aims to improve the quality of life for people struggling with a substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare provider.