# Developing and Strengthening Cannabis Warnings

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2024 · $608,472

## Abstract

ABSTRACT
Cannabis is the third most commonly used substance in the United States (US), with almost half of all US
adults reporting lifetime use. Cannabis use is associated with physical harms (e.g., respiratory diseases),
psychological harms (e.g., cognitive deficits), and other types of harms (e.g., car crashes). Despite these
harms, many adults underestimate or do not know about the risks of cannabis use. Warning labels on cannabis
packages are a population-level intervention that can increase risk perceptions, knowledge, and recall of
cannabis harms, however, there is a lack of research on how cannabis warnings can be improved. Currently,
most US states with legalized cannabis require text-only cannabis warnings, but they are often placed on the
back of packages, are small (e.g., 6-point font), are wordy (e.g., more than 100 words), and read like a legal
disclaimer. As a result, current cannabis warnings are unnoticed, hard to read, and confusing. Accordingly, the
long-term goal of this research is to develop cannabis warnings that inform people about cannabis harms and
that states can implement into their cannabis warning regulations. The overall objective of this research is to
rigorously examine the current landscape of cannabis warning regulations and experimentally determine which
warning characteristics most effectively communicate the harms of cannabis use. The central hypothesis is
that large cannabis warnings with characteristics found to be promising (e.g., have icons, include colors) will
increase risk perceptions of cannabis harms. To accomplish our long-term goal and objective, the proposed
study will include three specific aims: Aim 1: Examine the legal and regulatory landscape of US cannabis
warnings; Aim 2: Develop a set of evidence-based cannabis warnings and identify which warning
characteristics increase perceived warning effectiveness; and Aim 3: Experimentally determine if large
cannabis warnings with characteristics found to be promising in Aim 2 increase risk perceptions, knowledge,
and recall of cannabis harms. Included within these aims are rigorous and innovative methods: a
comprehensive legal analysis, key informant interviews with cannabis regulators, an expert panel review,
online experiments, and a discrete choice experiment. Throughout the project, we will disseminate findings
from our study to regulators so that they can implement evidence-based warnings and impact change in the
cannabis regulatory landscape. This project is significant because each state that legalizes cannabis is tasked
with developing regulations on warning labels, but there is a lack of rigorous published research, especially
from the US, on the effectiveness of different cannabis warning themes (e.g., content), characteristics (e.g.,
text length, color) and format (e.g., size). Therefore, our project can help meet a critical need for a
comprehensive and rigorous evaluation of cannabis warnings. The proposed study directly addresses NIDA’s
p...

## Key facts

- **NIH application ID:** 10801813
- **Project number:** 1R01DA058003-01A1
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Sarah Kowitt
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $608,472
- **Award type:** 1
- **Project period:** 2024-06-15 → 2029-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10801813

## Citation

> US National Institutes of Health, RePORTER application 10801813, Developing and Strengthening Cannabis Warnings (1R01DA058003-01A1). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10801813. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*