A single Percocet is effectively eliminated from your body within about 20 to 25 hours, though drug tests can detect it for longer. Percocet contains two active ingredients, oxycodone and acetaminophen, and each clears at a different rate. The oxycodone component is the one that matters for drug testing and is detectable in urine for 1 to 3 days after a single dose.
How Long Until Percocet Leaves Your Body
Oxycodone, the opioid in Percocet, has a plasma half-life of 3 to 5 hours. That means every 3 to 5 hours, the concentration in your blood drops by half. A drug is considered effectively eliminated after 4 to 5 half-lives, when roughly 94% to 97% of it has been cleared. For oxycodone, that works out to about 15 to 25 hours.
The acetaminophen component clears faster. It has a half-life of about 4 hours in healthy adults and is fully absorbed within 2 hours of taking the pill. About 90% is processed by the liver into inactive compounds that get flushed out through urine, with only 2% leaving the body unchanged. After roughly 16 to 20 hours, the acetaminophen from a single Percocet is essentially gone.
Pain relief wears off well before the drug fully leaves your system. A single immediate-release Percocet provides 3 to 6 hours of pain control, even though trace amounts of oxycodone remain in your blood for many more hours after that.
Urine Test Detection Windows
Urine testing is the most common method, and a single Percocet is typically detectable for 1 to 1.5 days. However, the body breaks oxycodone down into metabolites (byproducts of metabolism) that can linger longer. Two key metabolites, noroxycodone and oxymorphone, are detectable in urine for up to 3 days after a single dose, according to Mayo Clinic Laboratories.
One important detail: standard opiate urine screens often miss oxycodone entirely. It typically screens negative on a basic opiate immunoassay, which is designed to catch drugs like morphine and codeine. To detect oxycodone, the test has to specifically look for it. Federal workplace testing uses a cutoff of 100 nanograms per milliliter for oxycodone in urine, meaning levels below that threshold won’t trigger a positive result.
Saliva and Hair Testing
Oral fluid (saliva) tests use a lower detection threshold than urine: 30 nanograms per milliliter for the initial screen and 15 nanograms per milliliter for confirmation. The lower cutoff makes saliva tests more sensitive, though the detection window for a single dose is generally shorter than urine, typically 1 to 2 days.
Hair testing works on a completely different timeline. Hair captures a record of drug exposure as it grows, with each half inch representing roughly one month. A standard 1.5-inch hair sample covers a 90-day window. A single dose of Percocet is far less likely to show up on a hair test than repeated use, but the possibility exists within that window.
Factors That Slow Clearance
The 20-to-25-hour estimate assumes a healthy adult with normal organ function. Several factors can extend how long oxycodone stays in your system.
Liver health has the biggest impact. Your liver does most of the work breaking down oxycodone, primarily through a liver enzyme called CYP3A4. In people with moderate to severe liver disease, peak blood levels of oxycodone increase by about 50%, and total drug exposure (the amount your body has to process over time) nearly doubles, rising by 95%. That translates directly into a longer clearance time.
Kidney function also matters. Impaired kidneys increase oxycodone concentrations by roughly 50%. Since the kidneys are responsible for flushing out metabolites, reduced kidney function means those byproducts stick around longer, which extends the detection window on drug tests.
Age plays a role as well. Older adults generally clear opioids more slowly. This is partly due to natural age-related declines in liver and kidney function, and partly because body composition changes affect how drugs are distributed and stored.
Other medications can interfere with oxycodone metabolism. Drugs that inhibit the CYP3A4 or CYP2D6 liver enzymes slow the breakdown process, causing oxycodone to accumulate. When CYP2D6 activity is blocked, for example, the body produces more noroxycodone (an intermediate metabolite) and less oxymorphone. In at least one documented case, impaired CYP2D6 metabolism led to oxycodone toxicity from accumulation. Common CYP3A4 inhibitors include certain antifungal medications, some antibiotics, and grapefruit juice.
Body Weight, Hydration, and Metabolism
Beyond organ function and enzyme activity, general physical factors influence clearance speed. People with higher body fat percentages may retain oxycodone slightly longer because opioids are somewhat lipophilic, meaning they can be absorbed into fat tissue and released more slowly. Hydration levels affect how quickly your kidneys can filter and excrete metabolites, though drinking extra water won’t dramatically speed up the process. A faster baseline metabolism generally means faster drug clearance, which is one reason younger, more physically active people tend to eliminate oxycodone on the shorter end of the range.
Single Dose vs. Repeated Use
Everything above applies to a single Percocet taken in isolation. If you’ve been taking Percocet regularly, even for a few days, the drug and its metabolites build up in your system. Repeated dosing means your body hasn’t fully cleared one dose before the next arrives, so the total amount that needs to be eliminated is significantly higher. In that scenario, urine detection windows can extend well beyond the 1-to-3-day range for a single pill. The metabolites noroxycodone and oxymorphone are especially persistent with repeated use, as they accumulate faster than the body can excrete them.