What We Know Now About the Window of Detection for Fentanyl

What We Know Now About the Window of Detection for Fentanyl

Fentanyl use continues to rise, and with increased usage comes increased data, and an increased understanding of the pharmacology of this extremely potent synthetic Opioid. In fact, chronic Fentanyl use is a relatively new phenomenon. I suspect that over time we will get an even clearer picture of what the long-term effects of Fentanyl use and misuse are.

If you had asked me a month ago how long Fentanyl is detectable in urine, I would have given my answer based on the common wisdom at the time: 4-5 days. However, around this time I learned some new information that has forever changed my answer to this question.

The situation was as follows: one of our clients looking at the lab results for one of her participants, asked me for clarification of what the results might mean. The result indication no presence of Fentanyl, but 76 ng/mL of Norfentanyl (the primary active metabolite of Fentanyl) was confirmed present. My first thought was use in the preceding 4-5 days – as there was only the metabolite present, which we typically see near the outset of the window of detection. Discussing this further with our client, she indicated that this participant had been in jail for the 2 weeks prior to this specimen. We all know that it isn’t impossible to find drugs in jail, but she was confident this wasn’t the case in this situation. Luckily, while I like to brag about my 20 years’ experience and my boundless knowledge, I do have people I can turn to who have even more experience and an even deeper knowledge than I. My go-to toxicologist told me the story of a family member who had tested positive for Norfentanyl for weeks after last use. She apologized that she could not find any studies to back this up, and this was strictly anecdotal. After digging for a while, I too was unable to find any serious research to back this up. I was frustrated as I was not about to start sounding the alarm based solely on anecdotal evidence. So, I simply set the story aside for the time being.

Fast-forward about 3 weeks when I was discussing lab results with a different client. One of the lab results we looked at was a similarly high level of Norfentanyl confirmed, while Fentanyl was not present – almost an identical looking result to the one that started this. This led to a discussion about Quest Laboratories telling her they were investigating this same theory, and they were compiling Fentanyl confirmation result. More importantly, this led to a renewed (and more frenzied) search for some shred of clinical evidence that there was some truth to this (thanks Jennifer!).

I was finally able to find a reliable source of data in the form of this article from Boston University. It is by no means thorough enough to be the last word on this matter, but it was detailed enough for us to want to share this information with you. In summary, it explains that Fentanyl is lipophilic (which means dissolved in fat cells, as opposed to water), much like THC, and as such will build up over time with chronic use. This means that the window of detection for chronic Fentanyl users can be as long as 26 days or more.




Delta 8 Vlog


A Closer Look into Synthetic Cannabinoids, Also Known As, K2/Spice

A Closer Look into Synthetic Cannabinoids, Also Known As, K2/Spice

One of the so-called “designer drugs” we talk about frequently is colloquially known as “K2/Spice”; named for the earliest products to became popular in the U.S. This colloquialism is why the drug testing industry decided to call our synthetic cannabinoid test a “K2/Spice Test”. More accurately, these substances are called “synthetic cannabinoids”. This designation is because the active chemicals bind to the same cannabinoid receptors in the human body that THC – the primary psychoactive component of marijuana – affects. In fact, this group of substances was synthesized in an attempt to find an alternative to marijuana. Interestingly enough, this research was funded by NIDA (National Institute on Drug Abuse).


The first synthetic cannabinoid was synthesized in 1988; it was created by an organic chemist at Clemson University named John W. Huffman. He used his initials and designated this range of chemicals JWH-XXX (XXX representing the version numbers of his creations). There are nearly 400 active substances synthesized by Dr. Huffman (JWH-004 through JWH-425, with a few gaps for versions that were inactive or otherwise not optimal). We first started seeing evidence of these chemicals in illicit formulations in 2008, with JWH-018 & JWH-073 being the earliest; as mentioned above, the first retail products that we saw were K2 and Spice.


While there are a couple of synthetic cannabinoids that have an acceptable medical use, the vast majority of them are rightly considered dangerous drugs. Some of the effects (usually at lower doses) do mimic the effects of THC, but the side-effects are much more severe than THC and can include paranoia and psychosis. It is such an extreme substance that Dr. Huffman himself has said “It bothers me that people are so stupid as to use this stuff”.


As with the naming scheme, the drug testing industry also targeted these earliest versions of this burgeoning drug when determining which substances the test should detect. As such, the earliest tests were simply detecting the JWH-018 & JWH-073 (and their metabolites). As governments scrambled to enact laws against these substances, the manufacturers turned to other synthetic cannabinoids in their products to try and stay ahead of the law. Thus began the great “whack-a-mole” between manufacturers, law-makers, and drug test manufacturers trying to stay ahead of the changes. Currently our K2/Spice test detects 18 different substances. Unfortunately, not including the JWH compounds, there are 100+ synthetic cannabinoids that have been synthesized, but the test is constantly evolving. Recently we started seeing a synthetic cannabinoid hitting the streets that is a different structural classification (one of seven such classifications) – still part of the 100+ mentioned above. Substances in this classification, as well as the tests for them, are being colloquially referred to as K3. The K3 test detects another 14 substances. Currently the best solution for detecting synthetic cannabinoid use would be a “K2/K3 Combo” test; it is a test that has separate test areas for both classifications and provides a total of 32 substances detected.


Luckily, as of now, synthetic cannabinoid use is on the decline. Hopefully tighter enforcement and education will continue this trend. In the meantime, we will – as always – continue our progress in providing you a method of detecting these dangerous substances.