Warning Labels on Delta-8 THC Products Increased Youth Awareness of Intoxication and Harm
When adolescents viewed delta-8 THC products with warning labels, they rated the products as more intoxicating and harmful, with the strongest effects among cannabis-naive youth and for edible products.
Quick Facts
What This Study Found
Among 3,647 Southern California adolescents, those shown delta-8-THC products with larger warning labels (vs. unmodified packaging) reported greater anticipated intoxication, higher perceived health harm (RR=1.07), and greater belief that delta-8 products are as harmful as marijuana (RR=1.04). Warning label effects were stronger for edible products and for never-cannabis-using youth. However, warning labels did not reduce susceptibility to use. Differences between standard and larger warning labels were minimal.
Key Numbers
3,647 adolescents; larger labels: +2.50 points anticipated intoxication; perceived harm RR=1.07; risk perception RR=1.03; equal/more harmful than marijuana RR=1.04; no effect on use susceptibility; effects stronger for gummies vs vape; stronger for never vs ever users
How They Did This
Mixed within-between-subject experiment in a 2023 survey of 3,647 Southern California adolescents. Randomized to view delta-8-THC edible and vape products under three conditions: unmodified, standard warning label, or larger warning label. Measured anticipated intoxication, perceived harm, and susceptibility to use.
Why This Research Matters
Delta-8-THC products are widely available, often marketed as "legal THC," and unregulated in many states. This study provides the first experimental evidence that warning labels can increase youth awareness of these products' risks, though they may not be sufficient to deter use.
The Bigger Picture
Delta-8-THC occupies a regulatory gray area in the US, sold as a hemp product but producing psychoactive effects. As these products proliferate in gas stations and convenience stores without cannabis market regulations, labeling requirements could be a minimal intervention.
What This Study Doesn't Tell Us
Lab-based experiment showing hypothetical products; real-world effects may differ. Southern California sample may not generalize nationally. Effect sizes were small. Warning labels did not reduce susceptibility to use, limiting practical impact. Single exposure; repeated exposure effects unknown.
Questions This Raises
- ?Would sustained exposure to warning labels reduce use susceptibility over time?
- ?What label content would most effectively deter youth from trying delta-8 products?
Trust & Context
- Key Stat:
- Evidence Grade:
- Moderate: large experimental sample with randomization, but lab setting and small effect sizes limit real-world implications.
- Study Age:
- 2025 publication using 2023 data
- Original Title:
- Impact of Delta-8-THC warning labels on perceived intoxication, harm, and susceptibility among adolescents.
- Published In:
- The International journal on drug policy, 139, 104781 (2025)
- Authors:
- Harlow, Alyssa F(7), Leventhal, Adam M(7), Barrington-Trimis, Jessica L(5)
- Database ID:
- RTHC-06636
Evidence Hierarchy
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-06636APA
Harlow, Alyssa F; Leventhal, Adam M; Barrington-Trimis, Jessica L. (2025). Impact of Delta-8-THC warning labels on perceived intoxication, harm, and susceptibility among adolescents.. The International journal on drug policy, 139, 104781. https://doi.org/10.1016/j.drugpo.2025.104781
MLA
Harlow, Alyssa F, et al. "Impact of Delta-8-THC warning labels on perceived intoxication, harm, and susceptibility among adolescents.." The International journal on drug policy, 2025. https://doi.org/10.1016/j.drugpo.2025.104781
RethinkTHC
RethinkTHC Research Database. "Impact of Delta-8-THC warning labels on perceived intoxicati..." RTHC-06636. Retrieved from https://rethinkthc.com/research/harlow-2025-impact-of-delta8thc-warning
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.