Fentanyl has become a serious problem in the ongoing opioid crisis. It is 50 times stronger than heroin and 100 times stronger than natural opioids like morphine; it’s also cheap to produce and is extremely potent, even in miniscule quantities. As a result, it is commonly added to street drugs to increase their effects and make them more addictive. From 1999 to 2021, synthetic opioids like fentanyl were responsible for the majority of overdose deaths in the United States. 

With such scary data emerging about fentanyl-related deaths, it’s easy to forget that pharmaceutical fentanyl serves a real medical purpose and can be taken safely under the direction and supervision of a physician.

To understand the purpose of fentanyl, we must understand its effects on the body — including how long users can expect the drug to stay in their system.

What Is Fentanyl?

Fentanyl is a synthetic opioid that works by binding to opioid receptors in the brain and interrupting pain signals being transmitted from the brain to the body. Fentanyl was first synthesized in 1960 by Belgian chemist Paul Janssen for use as an intravenous anesthetic during surgery; it has since been approved to treat severe and chronic pain caused by advanced cancer, major surgery, and acute trauma. It is also used in the treatment of breakthrough cancer pain.

Pharmaceutical fentanyl is given as a shot, a transdermal patch worn on the skin, or a transmucosal lozenge (used like a cough drop). 

How Is Fentanyl Detected in the Body?

Fentanyl can be detected in the urine for up to 72 hours after use. However, standard drug screens (like those given during the pre-employment phase) don’t include it on their list of detectable substances. It can, however, be tested for on a case-by-case basis. Fentanyl can also be detected in saliva and blood with certain testing methods, but this type of detection is far less common because the tests are more expensive and complex than standard drug screens. 

How Long Is it in Your System?

The effects of fentanyl may not last long (something that contributes to addictions), but the drug does stay in your system for an extended period. Depending on the dose and, more importantly, the test you take, fentanyl can be detected as long as three months after use.

Type of Drug Test Length of Time Between a Positive Test
Urine Tests 24 and 72 Hours (1-3 Days After Use)
Blood Tests As Soon as 5 Hours and as Late as 48 Hours
Saliva Varies; Saliva Is Usually Not Considered an Effective Testing Method
Hair Tests Up to 3 Months


Fentanyl detection in street drugs

Illicit drugs have been adulterated (laced) with Fentanyl derivatives for decades. Drug dealers may add it to their supplies to make them more potent, allowing them to traffic in smaller quantities and reduce their costs. Fentanyl is also highly addictive, which can quickly create a stream of repeat customers who are dependent on the drug and will pay extreme prices to obtain it. 

The increased presence of fentanyl in supplies of street drugs like heroin, cocaine, and methamphetamine has contributed to an increase in opioid-related overdoses and deaths. Fentanyl test strips (FTS) are small, affordable strips of paper that can accurately detect the presence of Fentanyl in almost all street drugs, whether they’re in powder, pill, or liquid form. 

Behavioral and physical side effects of fentanyl

While laboratory tests are the only guaranteed way to detect Fentanyl in a person’s body, there are some outward signs you can look for if you suspect a loved one is abusing the drug:

  • Weight Loss
  • Itchy Skin
  • Slowed Cognitive Functions
  • Increased Appetite for Extreme Acts
  • Euphoric Moods
  • Problems Sleeping
  • Deteriorating Hygiene
  • Depression
  • Relentless Cravings

Is Fentanyl Addictive?

Fentanyl is fast-acting and extremely potent, making it highly addictive. In some cases, patients have reported feelings of dependency after a single dosage of Fentanyl. Because Fentanyl analogs like carfentanil and acetylfentanil are often added to street drugs in loose, inexact quantities, users often consume much higher doses than they realize, exacerbating their risk of dependency and overdose.

With such a high risk of addiction, many people who use Fentanyl experience withdrawal symptoms when they attempt to wean themselves off the drug. 

Symptoms of Fentanyl withdrawal include: 

  • Agitation
  • Muscle Pains
  • Fever
  • Sweating and Chills
  • Nausea
  • Insomnia
  • Restlessness

Treatment for Fentanyl Addiction

Steps to Recovery offers safe detox and rehab for people struggling with opioid addiction and withdrawal. Our rehab facility helps people with opioid use disorders get clean and start building the life skills and coping mechanisms they need for lasting recovery. 

If you’re need treatment for Fentanyl addiction, reach out to Steps to Recovery today by calling 267.209.7312.