(NewsNation) — Officials across the U.S. are working to combat the flow of fentanyl that has led to overdose deaths and the continued opioid epidemic.

Earlier this year, California officials announced they had seized nearly six million fentanyl pills in the early months of 2024, but it isn’t just a problem for states along the southern border. Fentanyl has also been coming into the country through seaports and being distributed throughout the interior of the country.

The drug is so pervasive on the illicit narcotic market that other drugs are turning up contaminated with fentanyl. It’s reached a point where some drug dealers are using fentanyl test strips to show customers their illegal drugs aren’t laced with the synthetic opioid, which can be deadly in very small amounts.

But can you trust test results from these strips, which cost about $1 each?

“They do detect the presence of fentanyl very effectively,” Placer County, California Sheriff’s Deputy Patrick Craven told NewsNation earlier this year.

The California Department of Public Health says fentanyl “nearly impossible” to detect laced into other drugs without the strips.

“Test strips are inexpensive, typically give results within 5 minutes, and can be the difference between life or death,” the CDPH writes in an online summary of fentanyl risks. “Even if the test is negative, caution should be taken as test strips might not detect other fentanyl-like drugs, like carfentanil.”

Some dealers are even posting photos of the strips on social media, something that’s more difficult for companies to crack down on, Craven said.

While fentanyl test strips can help people know what they are ingesting, Craven warned that anyone buying illicit drugs should be skeptical of buying substances via social media or simply based on the word of a drug dealer that they have tested.

“The idea of trusting someone that posts the video or posts the picture that their drugs test clean for fentanyl is scary,” he said.