How Long Does Ketamine Stay in Your System?

If you’re asking how long ketamine stays in your system, the answer depends on what you mean by “in your system.” The effects of ketamine wear off relatively quickly but the substance itself and its metabolites can remain detectable in your body for much longer than you might expect.

How ketamine is metabolised

When ketamine enters the body, the liver does the heavy lifting and it converts around 80% of a ketamine dose into a metabolite called norketamine. This is done through a process called N-demethylation and the enzymes responsible for this are found in liver tissue.

Norketamine is then broken down further into other metabolites, including dehydronorketamine (DHNK). This matters because while ketamine itself has a half-life of around two to four hours, these metabolites hang around in the body for considerably longer.

Only about 2% of ketamine is excreted unchanged in urine and the rest leaves the body as metabolite byproducts. These byproducts pass through your urine over the course of several days.

How long do ketamine’s effects last?

The effects of ketamine depend on how it’s taken and how frequent it’s used. For example, when it’s snorted, the dissociative effects typically begin within minutes and last somewhere between 30 and 60 minutes.

When taken orally, the onset is slower and the effects can last slightly longer but they still tend to resolve within around 90 minutes.

It’s worth remembering though, that feeling “normal” again does not mean the drug has left your system. Ketamine metabolites continue to circulate and be excreted long after the main effects have worn off. This is exactly why drug tests that test for ketamine specifically can return positive results days or even weeks after your last use.

Ketamine detection times

How long ketamine shows up on a drug test depends on the type of test being used.

Urine tests are the most common method, largely because after a single dose, ketamine can be detected in urine for up to five days. Norketamine is also detectable for up to six days and DHNK for up to ten days, which is why urine is the go-to detection method.

If you use ketamine regularly over a long period of time, that detection window is extended. One study of chronic ketamine users found that urine remained positive for ketamine metabolites for anywhere between 22 and 96 days after stopping use.

As a side note, it’s also worth noting that ketamine is not included in standard workplace drug panels and has to be specifically requested.

Blood tests are another detection method but ketamine in the blood has a shorter detection window. Ketamine is typically detectable in blood for around 4 to 24 hours after a single dose, although certain metabolites may still show for up to three days.

Saliva tests can detect ketamine for approximately 24 to 48 hours after use.

Hair tests offer the longest window and hair samples cover roughly four to seven months of exposure history, with longer samples extending that window further.

Both ketamine and norketamine need to be present in the sample to confirm active use rather than environmental contamination, which means coming into contact with ketamine from other users.⁷

What affects how long ketamine stays in your system

Several factors influence how quickly your body clears ketamine, meaning that there isn’t a specific time period for everyone who takes the drug.

Risks of repeated ketamine use

If you’ve found this page because you’ve used ketamine and are expecting a drug test at work or maybe even searching for ways to beat a drug test, it’s worth pausing on that idea for a moment. If ketamine usage has now spilled over into your working life, it’s safe to assume that your use is leaning towards the heavier side. But heavy ketamine usage can bring a wealth of different problems, both physically and mentally.

One of the most well-documented consequences of chronic ketamine use is damage to the bladder. Ketamine metabolites are directly toxic to the lining of the bladder and this can lead to a condition known as ketamine-induced cystitis.

Symptoms include frequent urination, pain when urinating, blood in urine and severe abdominal discomfort.

In fact, the ACMD’s 2026 review found that around a quarter of regular ketamine users experience at least one urinary symptom. But the good news is that if use stops early enough, symptoms can improve but advanced cases may require surgical intervention.

Cognitive effects are another concern and research has linked frequent ketamine use to impairments in executive functioning, which includes aspects like memory recalling and planning. Some of these deficits appear to recover with sustained abstinence but others, particularly around episodic memory, may be longer-lasting.

When to seek help

If ketamine has become something you rely on to get through the day or if you’ve noticed that you need more of it to feel the same effects, those are signs that your use may have moved beyond recreational use.

Coupled with this, if you’re experiencing any of the physical symptoms that we mentioned today, especially bladder pain, it’s important not to ignore these signs.

If you’re a concerned loved one, it can be a little more difficult to spot the signs of ketamine addiction but there are signs there nevertheless. If you’ve noticed your loved one withdrawing from others or maybe even activities they like doing, along with ketamine related use signs, it could indicate they’re heavily involved with the drug.

If you fit any of these two profiles, it’s worth reaching out for more help. Addiction of any kind is a complex condition and trying to manage it on your own can be very difficult. Liberty House provides residential treatment for ketamine addiction within a supportive environment.

Speaking with a member of our team can help you understand where you stand and what your options are. You don’t need to have everything figured out before making that call and any questions you may have can be answered by a member of our team. Contact us today.