Fentanyl Test Strip



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About this test

The most sensitive, cost-effective, and accessible method for checking if your drugs contain fentanyl is by using Fentanyl Test Strips.
These strips were originally developed to test for fentanyl in urine, and have been found to work equally well for detecting fentanyl in any sample. The test strips that we sell here at DoseTest are the most reliable on the market.
The Fentanyl Test Strips are manufactured by BTNX, catalog number FYL-1S48-100.

Why test

Whatever your choice of drug is, Fentanyl is more and more frequently popping up in samples such as Cocaine and Amphetamine, using these low-cost testing strips is the easiest way to ascertain whether or not your sample contains Fentanyl.

How to use

We recommend two different ways of testing, depending on if you have a solid or liquid sample.

Solid samples

      1: Mix your sample well. If you are testing a pressed tablet or pill, using a clean knife, break off a small part and crush it into a powder. If your substance is already in the form of a powder, mix it as thoroughly as possible.

2: Due to the sensitivity of fentanyl test strips, only a very small quantity (as much as a few grains of salt, ~5 mg) is needed. Place this amount into a cup, and add 5 mL (or 1 teaspoon) of tap water. As fentanyl is readily soluble in water, rigorous mixing is not needed.

3: Open the test strip package, and dip the test strip into the cup for 15 seconds, with the side that has the wavy lines pointing down. Do not submerge the strips over the wavy lines!

4: Remove the strip from the sample and set it horizontally on a clean surface. Wait 1-3 minutes before interpreting the result.

We recommend performing the test multiple times each time using a different part from your drug, to ensure there’s not a specific “hot-spot” with Fentanyl in.

Liquid samples

1: If preparing a shot for injection, first prepare the shot and fill your syringe. Then, with only the residue left over (1 drop or less), pour 5 mL (1 teaspoon) of tap water into the cup.

2: If your sample is in a bottle or vial, gently shake the container, and dispense one drop into a cup. Then add 5 mL (1 teaspoon) of tap water into the cup.

3: Open the test strip package, and dip the test strip into the cup for 15 seconds, with the side that has the wavy lines pointing down. Do not submerge the strips over the wavy lines!

4: Remove the strip from the sample and set it horizontally on a clean surface. Wait 1-3 minutes before interpreting the result.

Testing scenarios

False positives
Methamphetamine and MDMA are two drugs that can cause false positives with fentanyl test strips. When testing these substances it is important to make sure your dilution is about 1 mg/mL. Using the above protocols, false positives should be minimized, however if you are testing one of these substances and obtain a positive result, it is recommended to increase your dilution and test again with a new test strip. If the second test is also positive for fentanyl, it should be assumed that fentanyl is present in your sample.
Other substances that may cause false positives:
Isopropylphenidate or IPPH

Different results for the same sample
If two different results are read for the same sample, repeat the test again. As such a small amount of the sample is tested, and as solid samples such as pressed pills or powders might not be homogenous, it is possible that fentanyl may be present in your sample only in one area of the pill or baggie. This is why it is best to test more than one area of a pill or of a powder and to mix your sample as much as possible before testing! It may be wise to test a larger quantity of your substance, which will allow for a more accurate representation of your sample. To do this you would dissolve 15 mg of your sample (0.015 g) in 15 mL (1 tablespoon) of tap water. Keep a ratio of 1 mg sample to 1 mL water to reach the optimal zone well above the detection limit of the strips and below the area where other compounds in the sample could produce a false result.

Faint second line
Sometimes after dipping the strip in the test solution a faint second line appears, leading to confusion when interpreting the result. Most harm reduction organizations assert that any second line, no matter how faint, should be interpreted as negative (3). For the minimization of risk, we recommend re-testing your sample with a new test strip if you are unsure of how to interpret the result.

Control line does not show up
If the control line, which is the top line when the strip is held with the wavy side at the bottom, does not appear, it means the fentanyl test strip is defective and should be discarded. Test again using a new strip.

These were excellent
These were excellent and worked very precisely seeing I have no previous lab skills. The results were dead on and it answered all my questions!
Fast Shipping
Fast shipping. Test strips work great. I already recommended to friends. Great price too.
Thank you for making Fentanyl test strips easy to use and affordable!
Together we can save lives ❤️
Dosetest is the place to go!
Let me start off by saying Dosetest is the place you want to go conduct your test. First and foremost they care about your general safety and take that into consideration. Secondly...
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Common questions
What is the detection limit of the Fentanyl Test Strips?
The detection limit of the strips is 20 ng/mL. This means that with a dilution factor of 1 mg/mL, to be under the detection limit of the strips, your sample would have to contain less than 0.02% fentanyl.
How do the test strips work?
The mechanism of the test strip as a whole may seem complicated, but each component can be understood! When the strip is dipped in water, the sample liquid moves up the test strip carrying the sample with it. Each strip also contains the control particles on the part that is dipped into water. These molecules are there to confirm that the strip is working properly. As the sample and the control move up the test strip, they will arrive at the area where the results are read. The control line only detects the control molecules, and produces a red colour when it attaches to the control. This means the strip was used properly. The result line is a bit different. If there is fentanyl or a fentanyl analog present, it will attach to the results line preferentially, blocking the control from creating the red color. If there is no fentanyl present, the control molecules will also bind to the results line. This is why one line is read as positive and two lines are read as negative! This type of test is called a lateral flow competitive immunoassay.
Do the test strips also detect analogues?
Fortunately, fentanyl test strips detect the following fentanyl analogs: carfentanil, acetyl fentanyl, butyryl fentanyl, remifentanil, ocfentanil, sufentanil, p-fluoro fentanyl, furanyl fentanyl, valeryl fentanyl, and 3-methyl fentanyl. The sensitivity of the test strips varies for each analog, this is accounted for by the dilution factor of 1 mg/mL.
What should I do if my drug contains Fentanyl?
We do not encourage or discourage drug use. What we aim to do is provide more information with the intention of reducing negative outcomes related to drug use. Whether or not there is a positive result, if you decide to consume the drug it is important to carry Narcan (aka naloxone), have a friend around who will be aware of your consumption, and start with low doses.
Can the test strips detect other opioids?
Fentanyl test strips only detect fentanyl and some fentanyl analogs. They cannot detect other opioids such as heroin or hydrocodone, nor opiates such as morphine or codeine.
If my sample doesn't dissolve in water, will the test still be accurate?
Even if the mass of your sample does not dissolve, if it contains fentanyl the test strips will be accurate. This is because fentanyl and its analogs dissolve in water.
How should I store the test strips?
The strips should be stored at temperatures between 2-30°C/36-86°F.
Can I drink the solution after testing?
Yes, with our Fentanyl Test Strips you can. However please note you cannot ingest any samples when testing with normal reagents such as Marquis (Mq).
Our Harm Reduction

DoseTest is here to shake up the harm reduction world, taking lifesaving materials like reagent test kits and fentanyl test strips from the small niche where they have lived and making them accessible to everyone. This doesn’t just mean selling them cheaper than everyone else, though. It means meeting people where they are and advancing both the materials and the information about how and why to use them. It means working together with everyone from state health departments to mutual aid groups to reach people that we never could alone.

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countries shipped to.
Over 3 million
individual tests worth of products distributed in the last year.
of tests given away at festivals and events.