Overdose deaths from opioids rose in Colorado, diverging from the national trend, which has been decreasing, according to a new study from a think tank.

In its new report, the Common Sense Institute said synthetic opioid overdose deaths in Colorado have grown by 17% since November 2024, the third-fastest growth rate in the country. The only states with higher spike rates are Arizona and New Mexico, according to the report.

If Colorado had followed the national trend, some 1,600 lives could have been saved, the study said, adding the opioid deaths represented a cost of roughly $18.3 billion.

“While this number does not encompass the entire value of human life, it does indicate that lives lost due to fentanyl and other opioids reduce the economic potential of the state,” the study said.

Synthetic opioid overdose deaths had been increasing in Colorado in 2018 through November 2023, mirroring the national trend and peaking at 1,213 that year, the report said.

After the peak, deaths in Colorado dipped, just as the country’s trend also decreased.

Then Colorado’s numbers deviated the year after.

If Colorado had followed the nationwide trend, which saw a 57% decrease in synthetic opioid overdose deaths, more than 1,600 lives could have been saved from November 2024 through August 2025, according to the report.

The study’s authors surmised that several factors contributed to the upward trend and pointed to Colorado’s “not as strict” drug laws.

“Colorado’s patterns in lessening criminal sentencing for drug offenses, implementing treatment-based courses of action for those who violate the drug crimes, and overall drug supply and trafficking history in the state, make it an environment where drug overdose numbers continue to increase,” the authors said.

Fentanyl possession and distribution penalties have long been a contentious at the state Capitol, stemming from a 2019 law that reduced penalties for possession of up to 4 grams of the drug from a felony to a misdemeanor.

In response to the overdose crisis, state policymakers in 2022 approved legislation to heighten the felony charges for possession of 1 to 4 grams of any substance containing fentanyl. Under the revised law, the criminal penalty for possession above 4 grams is a felony; under a gram, it is a misdemeanor.

In addition, the law allows defendants charged with the new felony to argue to a judge or jury that they didn’t know they possessed fentanyl, and if a “finder of fact” determines the defendant made a reasonable mistake of fact, the offense becomes a Level 1 drug misdemeanor.

That “knowing” requirement makes Colorado’s drug laws not as strict as Texas, where fentanyl is defined as a Schedule I drug and which includes expanded penalties for possession or distribution, according to the study.

The study’s authors said Texas saw its synthetic opioid overdose deaths drop by negative 27% since December 2024, “despite being a large magnet for in-migration.”

The tension at the state Capitol often revolves around how best to approach penalties, with “harm reduction” advocates arguing that stiffer punishments have not worked, while others countered that lax laws have exacerbated Colorado’s drug woes.

The arguments are familiar.

Testifying on drugs legislation in 2022, Lisa Raville of the Harm Reduction Action Center argued that a “harm reduction” approach tends to be a more effective treatment solution than incarceration. 

“People who use drugs and health care providers have a very tumultuous relationship,” she said. “For over 20 years, people have not wanted to access quality health care in the emergency departments because they were being warrant-checked and arrested out of there. That’s not to say that then they’re getting this really great care (upon being arrested). Now, they’re going to jail and getting no health care. People are almost losing limbs out there because they are so afraid to access quality health care.”

“We will never treat or incarcerate our way out of an unregulated drug supply, ever,” Raville added. 

Specifically citing legislation that would exempt doctors from being required to report injuries that patients have acquired via the use or possession of drugs, Republicans argued that the state should prioritize curtailing the flow of illicit drugs into Colorado and that incarceration plays a key role in curbing drug abuse. 

Then-Rep. Richard Holtorf, R-Akron, said that during his years on the Health and Human Services Committee, he has heard several accounts of former users saying incarceration is what got them clean. 

“I cannot support a bill that doesn’t allow for those people that need perhaps to be incarcerated to stop the drug use to save their lives,” he said. “This gives them a pass and lets people break the law with respect to outdated pharmaceuticals. It also tells doctors not to report health data to the Department of Health openly in this bill, going against every practice in every other part of health care.”

“It is antithetical, it doesn’t make sense to me,” Holtorf said, referring to the measure whose core provisions would exempt individuals who receive paraphernalia from a syringe exchange program from being charged with drug possession.

Reached for comment about the Common Sense Institute study, Colorado Department of Public Health and Environment said it has not finalized the 2025 morality data yet. The agency said that data will be available by late spring.

An agency spokesperson cited numbers from the most recent provisional data published by the CDC’s National Center for Health Statistics, showing synthetic opioid overdose deaths in Colorado increasing.

The October 2025 data set showed 1,792 total drug overdose deaths in the state, compared to 1,682 from the 12-month period ending in October 2024.

Of that number, 1,179 deaths involved all forms of opioid in 2025; there were 1,050 fatalities in 2024, the agency said.

The 2025 also showed that 1,005 deaths resulted from ingesting synthetic opioids, fentanyl being the primary drug, according to the state agency. In 2024, the number was 852.

“These trends do suggest the final number of overdose deaths in Colorado, and those involving opioids, may be higher in calendar year 2025 compared to 2024,” Paul Bishop, the health agency’s spokesperson, told The Denver Gazette.

It is difficult to narrow down the reasons for increasing trend and they are “rarely attributable to a single factor,” Bishop said, adding that the state and its partners work to increase access to “life-saving tools, such as naloxone and other evidence-based overdose prevention strategies.”

Denver Gazette Editor Luige del Puerto contributed to this article.