Frequently asked questions

What is community-based drug checking?

Drug checking is a process that chemically analyzes drugs to identify substances within a drug sample. This allows people who use drugs to make informed decisions around their drug use, preventing overdose and other harm. Many people are already familiar with fentanyl test strips, which are cheap and readily available in Los Angeles, but provide limited information and may provide a false sense of security. Our program uses test strips and other chemistry tools to provide more detailed results. Drug checking has been around since the early 1990s, but this is the first program of its kind in Los Angeles. This program partners with community organizations to provide this service and education to people who use drugs locally.


While drug checking is important to help reduce the risk of using unexpected or dangerous drugs, drug checking has several limitations. Drug checking:

1.       Can only confirm the presence of a substance, not the absence

2.       Cannot always detect substances that are present in small amounts, which is why we use several different tools for a broader understanding of a sample.

3.       May not detect new or rare substances if they are not listed not in the machine’s database

4.       Cannot always differentiate between substances that are chemically similar.

5.       Can identify the presence of a substance but not always the amount

6.       Is difficult to reliably run for plant or fungal material

7.       May not always detect components of a liquid sample if it is mostly water

Drug checking cannot determine whether drugs are safe or not to use. To prevent overdose and other harms, always carry naloxone, never use alone, start with a small, tester amount, and use sterile equipment.


What tools do you use for drug checking?

Tools used for drug checking may vary by program. Drug Checking LA uses Fourier-transform infrared spectroscopy (FTIR). When a beam of light passes through a sample, some of the light is absorbed by the sample and some of it is transmitted, or passes through, the sample. The machine then sees the unique “fingerprint” of each component of a sample, generating a wave that technicians interpret. This technique is useful for seeing substances that are greater than 5% of a sample. We also use several different types of immunoassay test strips, such as fentanyl test strips and benzodiazepine test strips, since these are both drugs that could be in a drug sample below the 5% limit on the FTIR and affect a person.

For secondary and confirmatory testing, we send out swabs of sample residue to a lab for DART mass spectrometry. This technique uses electrically charged molecules to interact with a sample and then weighs it the different pieces to identify what the sample contains.


Does drug checking destroy my drugs?

Drug checking with the FTIR spectrometer does NOT destroy your drugs as it works by shining a light through the sample. We offer opt-out testing with test strips where a few granules of sample need to be dissolved in water to run the strips. After drug checking, you will have the option of collecting your sample or leaving it with us for proper disposal.


What happens if I bring in a sample that is too small to be run on the FTIR spectrometer?

The spectrometer only needs a sample the size of a grain of rice, but in the event a client only has residue from a container or brings too little sample, we will still offer to run test strips and send a swab to the lab for DART mass spectrometry.


Are drug checking programs legal?

The legality of different drug checking techniques varies from location to location. In California, drug checking is legal through AB1598 (2022), which changed the Health and Safety Code so the definition of illegal drug paraphernalia excludes tools used to identify fentanyl, fentanyl analogues, ketamine, and GHB.


Bill Text - AB-1598 Controlled substances: paraphernalia: controlled substance testing. (ca.gov)


How do I find a drug checking location?

Please email us at checkingLA@proton.me, our secure, encrypted email address so we can provide you with an address and time for one of our drug checking clinics.


Fentanyl test strips can be purchased cheaply online through End Overdose, Dance Safe, and Wisebatch or obtained freely at local syringe service programs.


How long does it take to get the results back?

Results with the FTIR spectrometer and test strips usually take about 10 minutes or less per sample. We give clients a card with the written results. We also send out residue swabs to a lab for secondary and confirmatory testing with DART mass spectrometry. Those results take about a week to come back due to the time it takes to ship samples, but since our program is anonymous, we do not send those results to clients unless requested with contact information provided. If there is a concerning result from this additional testing, we will alert our community partners to create a plan for how to best inform clients.


I have a drug sample that I am concerned about. How do I get it checked ASAP?

Please contact us at checkingLA@proton.me, our secure, encrypted email address so our team can work with you. Remember, our drug checking services are public health and harm reduction-oriented, NOT clinical diagnostic tests.


Is it anonymous?

Yes, our program is anonymous and we do not ask for identifying information. We ask optional questions about client demographics to better understand how our services are reaching the community.


How is drug checking data used?

Results are reported to local public health organizations and harm reduction-oriented community partners to identify trends in the local drug supply and drug use. We do not collect any identifying information about clients.


How do you dispose of drug residues?

At the end of the drug checking clinic, we dispose of any remaining samples with DisposeRx powder. This powder and the samples are added to a vial, mixed with water, and shaken until a thick gel forms. This leaves the drug unusable, and it can be tossed in the trash.


What do results on the FTIR spectrometer look like?

The FTIR creates a unique spectrum, or wavelength, of all of the sample’s components that technicians then match to a reference library database of drugs, cuts, and other substances.

In the example below, a client brought a sample of meth. The red line shows the spectrum for the client’s sample, which matches up in shape well to a database wavelength of methamphetamine HCl.

Some samples are more complex and have several substances in them.

In the sample below, a client brought their fentanyl to be tested. The red sample spectrum matches closely to the blue database spectrum for fentanyl HCl, but we can see there is still another component in there.

After “subtracting out” the fentanyl on the laptop, we can more clearly see the sample also contains mannitol, a sugar, and common cut in West Coast fentanyl.

At the end of these subtractions, the technicians will see a relatively flat line and know they have identified all of the components that the machine can detect. Remember, the FTIR spectrometer can only see substances that are greater than 5% of a sample, which is why we utilize the other drug checking techniques as well.


Please note, technicians will also let clients know if they are unable to identify components in a sample, such as if a liquid sample is not concentrated enough, is a plant, or there is not enough sample to run on the machine.