Can Breath Tests Detect THC After Eating Cannabis Edibles? | Research

The takeaway

THC showed up in breath after eating cannabis edibles, but patterns varied widely between people and timing was unpredictable.

Policy researchers, forensic toxicologists, anyone interested in cannabis detection methods

19 of 29 participants showed a breath THC peak within 180 minutes of eating an edible

What the researchers found

19 of 29 participants showed a THC concentration peak in breath at 47, 92, or 180 minutes after eating a cannabis edible, while 6 had their highest reading before ingestion and 4 showed no significant change.

Why it matters

Breath-based cannabis testing is being explored as a roadside impairment tool, but almost all prior research focused on smoked cannabis. This is the first study examining whether edibles produce detectable breath THC changes, which is critical since edible use is growing.

The numbers in context

19 of 29 participants peaked at 47, 92, or 180 min; 6 had highest THC before ingestion; 4 showed no change; 5 additional cannabinoids detected; CBD trends sometimes diverged from THC trends

How the study worked

29 participants ate cannabis edibles and provided breath samples at baseline plus three post-ingestion timepoints using one of two sampling devices. Five cannabinoids beyond THC were also measured.

What this study cannot tell us

Small sample (29 participants), only three post-ingestion timepoints over 180 minutes, most participants had THC in pre-use breath samples suggesting prior use, only one edible dose tested

How to read the evidence

Small proof-of-concept study with only 29 participants and limited timepoints; first study of its kind for edibles

When this study was published

Published 2025

The bigger picture

As cannabis edibles become more popular, law enforcement and workplace testing may need different detection approaches than those designed for smoked cannabis. Breath testing for edibles appears feasible but far from reliable.

Questions still open

Why do some people show no breath THC increase after edible ingestion? Would a longer sampling window reveal delayed peaks? Can breath testing reliably distinguish recent edible use from prior smoked cannabis use?

Common questions

Can a breath test tell if you ate a cannabis edible?

In this study, most participants showed THC increases in breath after eating edibles, but the timing ranged from 47 to 180 minutes and some showed no change at all.

How is breath testing for edibles different from testing for smoked cannabis?

After smoking, breath THC spikes quickly and predictably. After edibles, the response was much more variable, with some people peaking nearly 3 hours later and others showing no measurable change.

Read the original research

The detection of cannabinoids in breath after ingestion of cannabis-infused edibles.

Journal of analytical toxicology, 49(9), 673-680

View on PubMed ↗Publisher’s paper ↗

Citation

Bery, Jennifer L; Brooks-Russell, Ashley; Lovestead, Tara M; Jeerage, Kavita M. (2025). The detection of cannabinoids in breath after ingestion of cannabis-infused edibles.. Journal of analytical toxicology, 49(9), 673-680. https://doi.org/10.1093/jat/bkaf063