(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.

Recently, California officials announced they have seized nearly six million fentanyl pills since January, 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.

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.

Placer County Sheriff’s Deputy Patrick Craven said the test strips can do a good job of identifying the presence of fentanyl.

“They do detect the presence of fentanyl very effectively,” he told NewsNation.

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.

“They have implemented AI programs to detect drugs; however, a simple test strip is not something that would otherwise be detected,” 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.

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