DEA Warns of Deadly Carfentanil-Fentanyl Mix in Colorado and Utah: What Families Need to Know

The Drug Enforcement Administration's Rocky Mountain Field Division issued an urgent public safety warning today following laboratory analysis of recent drug seizures in Colorado and Utah. DEA Southwest Laboratory testing identified illicit pills containing dangerous combinations of fentanyl mixed with carfentanil and fentanyl mixed with heroin—combinations that significantly increase overdose risk and complicate emergency medical response.

What the DEA Found

According to the DEA Rocky Mountain Field Division, recent law enforcement operations in both Colorado and Utah yielded tablets with two particularly concerning compositions:

Fentanyl/carfentanil mixtures: Carfentanil is a synthetic opioid approximately 100 times more potent than fentanyl and 10,000 times more potent than morphine. Originally developed as a veterinary tranquilizer for large animals, it has no approved human use.
Fentanyl/heroin combinations: While both are opioids, heroin is rarely found in pill form. Its presence in counterfeit tablets represents an unusual and dangerous formulation that may confuse users about what they are consuming.

"With these findings, once again we implore people in our communities to NEVER take a pill from anyone unless it comes from a prescribing doctor or pharmacy," said DEA Rocky Mountain Field Division Special Agent in Charge David Olesky in the agency's public statement.

Clinical Implications

The presence of carfentanil in the illicit drug supply presents serious medical challenges:

Extreme Potency: Carfentanil's potency means that microscopic amounts can cause fatal respiratory depression. The substance is so powerful that it has been studied as a potential chemical weapon.

Naloxone Resistance: While naloxone (Narcan) can reverse carfentanil overdoses, the extreme potency often requires multiple doses administered rapidly. Standard single-dose naloxone may be insufficient.

Delayed Recognition: Because carfentanil acts similarly to other opioids, overdose victims and bystanders may not realize a more potent substance is involved, delaying appropriate emergency response.

Prolonged Respiratory Depression: Carfentanil's effects may last longer than those of fentanyl or heroin, requiring extended medical monitoring even after initial naloxone administration.

What This Means for Families

If you have a loved one who uses substances, this alert underscores the critical importance of harm reduction strategies:

Carry Multiple Naloxone Doses

Given the extreme potency of carfentanil, anyone at risk of witnessing an overdose should carry multiple naloxone doses—ideally three to four nasal sprays or injectable kits. Be prepared to administer repeated doses if the person does not respond within 2-3 minutes.

Call 911 Immediately

Naloxone buys time, but it is not a substitute for emergency medical care. Always call 911 for any suspected overdose, and be prepared to administer rescue breathing if the person is not breathing normally. Colorado and Utah both have Good Samaritan laws that protect people who call for help during an overdose from prosecution for minor drug possession.

Never Use Alone

The "never use alone" rule is more critical than ever. Have someone present who can recognize overdose signs and administer naloxone. If using alone is unavoidable, services like the Never Use Alone hotline provide remote monitoring.

Test Small Amounts First

While fentanyl test strips cannot detect carfentanil specifically, using a small test dose and waiting to gauge effects can reduce risk. However, given carfentanil's extreme potency, even tiny amounts can be fatal.

Know the Signs of Overdose

Recognize the signs of opioid overdose:

Slow, shallow, or stopped breathing
Blue or gray lips and fingernails
Pinpoint pupils
Unresponsiveness or inability to wake
Choking or gurgling sounds
Cold, clammy skin

Where to Get Help

Emergency: Call 911 immediately for any suspected overdose.

Naloxone Access:

Colorado: Naloxone is available without a prescription at most pharmacies. The Colorado Department of Public Health and Environment maintains a list of naloxone distribution sites.
Utah: The Utah Department of Health and Human Services provides free naloxone through community partners and many pharmacies.

Treatment and Support:

SAMHSA National Helpline: 1-800-662-HELP (4357) — free, confidential, 24/7 treatment referral
Colorado Crisis Services: 1-844-493-TALK (8255) or text "TALK" to 38255
Utah Crisis Line: 1-800-273-TALK (8255) or 988 Suicide & Crisis Lifeline

Find Treatment:

Use SAMHSA's Treatment Locator to find medication-assisted treatment (MAT) providers in your area
Contact your local public health department for information about low-cost or free treatment options

The Broader Context

This warning comes as communities across the Mountain West continue grappling with the ongoing overdose crisis. While national data shows encouraging declines in overdose deaths in some regions, the western United States—including Arizona, New Mexico, Colorado, and Utah—has seen concerning increases in fatalities.

The emergence of carfentanil in the Rocky Mountain region follows similar reports from other parts of the country. In June 2026, Fort Smith, Arkansas police issued warnings after seizing carfentanil, noting that reversing such overdoses requires "multiple, high doses of naloxone, and emergency medical intervention is absolutely critical."

Bottom Line

The DEA's warning serves as a stark reminder that the illicit drug supply remains unpredictable and increasingly dangerous. For families with loved ones who use substances, preparation is essential: carry naloxone, know how to use it, never use alone, and call 911 at the first sign of overdose. These simple steps can mean the difference between life and death.

Dr. Rachel Bennett, MD, is a board-certified addiction medicine physician. This alert was medically reviewed on June 26, 2026.