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What is Fentanyl?

Fentanyl is a potent synthetic opioid analgesic that is similar to morphine but is 50 to 100 times more powerful. It is a Schedule II controlled substance [1], and it is typically used to treat patients with severe pain or to manage pain after surgery. It is also sometimes used to treat patients with chronic pain who are physically tolerant to other opioids. In its prescription form, fentanyl is known by such names as Duragesic, Actiq, and Sublimaze. According to the National Institute of Health (NIH) [2], fentanyl may be habit-forming. Taking certain medications with fentanyl may increase the risk of developing severe or life-threatening breathing problems, sedation, or coma.

Most recent cases of a fentanyl overdose and death in the U.S. are linked to illegally made fentanyl. It is sold through illegal drug markets for its heroin-like effect. It is often mixed with heroin and/or cocaine as a combination drug —with or without the user’s knowledge—to increase its euphoric effects. According to the Center for Disease Control and Prevention (CDC) [3], rates of overdose deaths involving fentanyl and fentanyl analogs (carfentanil) increased by over 16% from 2018 to 2019. More than 36,000 people died from overdoses involving synthetic opioids, including fentanyl, in 2019.

How Long Does Fentanyl Stay in Your System
How long does fentanyl stay in your system? Fentanyl is one of the strongest opioids out there and can cause an overdose in even the smallest amounts.

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What is Fentanyl Used for?

Fentanyl is used for the treatment of chronic pain. It’s normally used to treat pain experienced by cancer patients, particularly for “breakthrough pain”. This type of pain happens when a cancer patient has constant pain medicine already, such as morphine, but then experiences sudden, severe pain as well. Fentanyl works by acting on the brain’s opioid receptors to alter how the brain experiences pain and also reacts to it. Fentanyl is not intended to be used for pain that’s short-term and will go away in a few days or on an as-needed basis.

When it’s used for surgical applications, it’s often part of the anesthesia given to patients to prevent pain following the surgery. When fentanyl is prescribed medically, it’s available in several different forms, including a lozenge, a lollipop, a spray, a dissolving strip, a tablet, an injectable solution, and a patch that goes on the skin. Since there is a high likelihood of abuse and dependence with fentanyl when it’s needed, it’s used under medical supervision. Patients who are prescribed fentanyl are given a set of instructions, which include not drinking alcohol when taking it and checking with a pharmacist before taking any other over-the-counter or prescription medicines, vitamins or supplements.

How Long Does Fentanyl Stay in Your System?

Since fentanyl can be administered in so many different ways, the administration method determines how long the effects last and how long it may stay in your system. Even though fentanyl produces a fairly short-lasting high, it can last for 24 hours or more if taken via a transdermal patch. However, someone who takes fentanyl intravenously may notice that their “high” wears off after just 30 minutes.

What is the half life of fentanyl?

Depending on the method of administration, the half-life of fentanyl changes. The half-life of a drug like fentanyl is an estimate of the period of time that it takes for the concentration or amount in the body of that drug to be reduced by exactly one-half (50%).

It takes approximately 4-6 half-lives for a substance to completely leave the system. When injected intravenously, fentanyl has a short half-life of 2-4 hours. When taken orally or transdermally, however, fentanyl has a half-life of 7-17 hours. Even though the effects of fentanyl will wear off long before it is eliminated from your system, the drug will leave behind traces of itself in the form of metabolites. Metabolites are what drug tests screen for.

Even though fentanyl is more potent and dangerous than most other opioids, most standard drug tests do not recognize fentanyl. This is because drug tests look for metabolites – not actual drugs. And, since fentanyl doesn’t metabolize into morphine-like other opioids do, many drug tests will not detect fentanyl. However, if the person administering the test sends the sample to a lab or testing, fentanyl can be detected via an advanced drug test.

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Factors That Affect Fentanyl Detection Time

There is no way to say exactly how long fentanyl stays in your system because each person is different. There are many individual factors that influence drug detection times and how long drugs stay in the body. Most factors have to do with how your metabolism works, such as:

  • Dose: The more fentanyl in the body, the longer it will take to fully be eliminated from the body.
  • Metabolism: Impaired renal or liver function will lead to slower metabolism of fentanyl.
  • Location of the patch: Differences in thickness of the skin and subcutaneous fat in various places on the body mean that the rate of absorption of fentanyl is different depending on where the patch is placed.

How Long Does Fentanyl Stay in Your Urine?

While often undetected by standard drug tests, an advanced urine drug test can be used to identify fentanyl. In this case, fentanyl can be recognized in urine for eight to 24 hours, depending on various factors including age, weight, and more. While urine tests may not recognize fentanyl after a full day, other methods still detect it and the drug can continue to wreak havoc on the body after improper use.

How Long Does Fentanyl Stay in Your Hair?

Hair is one of the most telling features of a person’s health. Because of its relatively slow growth process, it is often one of the most accurate health history timelines. For this reason, hair drug testing can be one of the most effective and telling signs of long-term drug use. Fentanyl can be detected in hair for up to 90 days, about three months.

how long does fentanyl stay in your system
Because of this uncertainty, many people who misuse opioids now do “test doses” in hopes that they will be able to tell if the drug is laced with fentanyl.

How Long Does Fentanyl Stay in Your Blood?

Blood testing is one of the least effective methods of detecting drug use over a long period. Fentanyl can only be recognized in the bloodstream for up to 12 hours. Although it typically isn’t detectable in the blood for longer than half a day, the negative side effects of long-term opioid use manifest themselves in various ways, including life-threatening addiction and potential fentanyl overdose.

How Long Does Fentanyl Stay in Your Saliva?

Saliva can be used for a variety of tests — from DNA to drug testing. Doctors may take a saliva swab or spittle sample to learn more about a patient. Saliva drug tests are often more accurate than urine or blood tests as they can detect fentanyl for one to four days after use.

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Fentanyl Overdose 

Anyone who uses drugs that may contain fentanyl, even occasionally, is at risk of a fentanyl overdose. A fentanyl overdose can overwhelm the central nervous system, disrupting the pathways that control heart function and breathing. Many people who overdose on fentanyl will fall asleep and never wake up. If someone at risk of a fentanyl overdose is breathing exceptionally shallow or slow. This can decrease the amount of oxygen that reaches the brain, a condition called hypoxia. Hypoxia can lead to a coma and permanent brain damage, and even death.

Many drug dealers mix the cheaper fentanyl with other drugs like heroin, cocaine, MDMA, and methamphetamine to increase their profits, making it often difficult to know which drug is causing the overdose. Naloxone is a medicine that can treat a fentanyl overdose when given right away. It works by rapidly binding to opioid receptors and blocking the effects of opioid drugs. But fentanyl is more potent than other opioid drugs like morphine and might require multiple doses of naloxone.

Fentanyl Overdose Symptoms 

Fentanyl can have harmful cross-reactions with other sedatives. This can be seen in Klonopin detox symptoms (clonazepam), Xanax addiction (alprazolam), Ativan addiction (lorazepam), and alcohol abuse. The combination of these drugs will intensify the depressing effects on the central nervous system (brain and spinal cord). The following are symptoms of fentanyl overdose:

  • Body is limp
  • Awake, without the ability to speak
  • Changes in skin color (darker-skinned people look grayish or ashen and lighter-skinned people look bluish purple)
  • Vomiting
  • Face is pale or clammy
  • Fingernails and lips turn blue or purplish black
  • Pulse (heartbeat) is slow, erratic, or not there at all
  • Making a snore-like gurgling noise or “death rattle,” choking sounds
  • Loss of consciousness
  • Non-responsive to outside stimulus
  • Very slow, shallow, erratic, or stopped breathing

Fentanyl Withdrawal 

Although fentanyl is used and prescribed in medical settings, it is also diverted for street use. When purchased on the streets, fentanyl may be called “china girl,” “china white,” “china town,” or “apache.” The effects of fentanyl are similar to those of other opioids, however, they are far more intense. It goes without saying that it is difficult to quit Fentanyl without proper help. 

Fentanyl produces euphoric effects, which is what pushes people to start abusing the drug in the first place. It makes the user feel good. That’s why many people take it recreationally, not knowing the risks. And if a person is already addicted, attempting to quit without proper treatment will result in fentanyl withdrawal.

Fentanyl Withdrawal Symptoms

When someone who suffers from an addiction to fentanyl suddenly stops using, fentanyl withdrawal symptoms can occur. These can include:

  • Fentanyl cravings
  • Goose bumps
  • Runny nose
  • Increased tearing
  • Sweating
  • Hot and cold flashes
  • Excessive yawning
  • Insomnia
  • Nausea
  • Vomiting
  • Diarrhea
  • Muscles aches
  • Joint pain
  • Weakness
  • Stomach cramps
  • Anxiety
  • Agitation

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How to Safely Detox from Fentanyl?

Fentanyl addiction detox is the medically assisted withdrawal from fentanyl for optimal safety and comfort. Detox should be done as part of an overall recovery plan. It is important to remember that recovery from substance addiction takes much more than simply ending drug use. The underlying causes of the addiction and the mental illness from the addiction itself must be addressed for the best chances of a successful recovery.

Benefits of An Inpatient Fentanyl Detox Program:

  • 24/7 medical observation
  • Luxury facilities & amenities
  • Medication assistance for fentanyl withdrawal symptoms
  • Nutritional supplements provided to support detox
  • Access to alternative detox therapies

The inpatient treatment approach works best as it aims to change the person’s behaviors. Also, help them establish social support systems and better methods of coping with stress. A person will likely experience many different side effects from their drug use. These side effects may be emotional, physical, or mental. For example, someone in fentanyl withdrawal will likely experience many uncomfortable feelings and negative thoughts about life during the process of detox. Unfortunately for those with dependency, detox is an unavoidable first treatment step for fentanyl addiction and to avoid any possibility of a fentanyl overdose. 

Please, do not try to detox on your own. The detox process can be painful and difficult without medical assistance. However, getting through the detox process is crucial for continued treatment. We Level Up NJ provide proper care with round-the-clock medical staff to medically assist your recovery through our Fentanyl Treatment Program. So, reclaim your life, call us to speak with one of our treatment specialists. “How long does fentanyl stay in your system? ” is a question that many misusers of the drug may have. Our counselors know what you are going through and will answer any of your questions.

How long does fentanyl stay in your system
How long does fentanyl stay in your system?  It’s important to consult an addiction specialist about stopping taking fentanyl. 

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[1] DEA –

[2] NIH –

[3] CDC –