The Index of Cannabis Equivalence (ICE): A User-Centered Approach to Standardization of Cannabis Dose-Response.
Michelle St Pierre, Stacey Squires, Sarah Daniels, Tatiana A Sanchez, Zach Walsh
Journal of Psychoactive Drugs 2026 DOI: 10.1080/02791072.2025.2449932 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Survey Peer reviewed |
|---|---|
| Sample size | 1,368 |
| Population | Cannabis users aged 18–93 with a history of cannabis use, 42% female |
| Measures | Index of Cannabis Equivalence (ICE) |
| Topics | Cannabis |
| Keywords | Cannabinoid content Intoxication Measurement Standard dose |
| Key findings | The Index of Cannabis Equivalence (ICE) proposes low-dose equivalencies across modes: two puffs on a joint, pipe, or vaporizer equals one bong hit, a 5 mg THC edible, or a quarter dab of concentrate. The authors argue these user-derived ratings can support standardized cannabis dosing, while cautioning that results come from lower-tolerance users and may not generalize to higher-tolerance users. |
Abstract
The increasing acceptance of cannabis use, and policy changes in several jurisdictions has led researchers and public health experts to call for a standard cannabis dose. Standard dosing units are useful tools for regulation, substance use guidelines, data collection, consistency of research, as a means of communicating low-risk recommendations and dose-related effects, and for self-monitoring. Efforts to standardize cannabis dose have focused on cannabinoid content without considering tolerance or mode. Cannabis users with diverse motivations for use and varying experience rated low, medium, and high doses across seven modes of use. The participants (N = 1368; 42% female) were 18-93 years of age (M = 31.64, SD = 14.70) who had a cannabis use history. The Index of Cannabis Equivalence (ICE) identified the following low-dose cannabis equivalencies: two puffs on a joint, pipe, herbal or concentrate vaporizer is equivalent to one hit on a bong, a 5 mg/THC edible, and ¼ dab of a concentrate. These findings are based on responses from users with lower tolerance, which may limit generalizability to those with higher tolerance. The ICE proposes standardized cannabis doses through user-derived ratings across different administration routes. The meaningful standardization of units of cannabis products in a manner similar to what has been achieved for alcohol represents a valuable step in establishing standard doses across different modes of cannabis administration.
Comparable studies
Other cross-sectional and survey studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Cannabis use before age 15 and subsequent executive functioning 104 chronic cannabis users (49 early-onset before age 15, 55 late-onset after age 15)... | 2011 | Observational cross-sectional study | n = 148 |
| Patterns of simultaneous polysubstance use in drug using university students Drug-using university students | 2006 | Cross-sectional survey | n = 149 |
| Persisting Reductions in Cannabis, Opioid, and Stimulant Misuse After Naturalistic Psychedelic Use: An Online Survey Online survey respondents | 2020 | Cross-sectional survey | |
| User perceptions of the benefits and harms of hallucinogenic drug use: A web-based questionnaire study Users of hallucinogenic drugs who completed a web-based questionnaire | 2010 | Cross-sectional survey | n = 600 |
| Illicit Use of LSD or Psilocybin, but not MDMA or Nonpsychedelic Drugs, is Associated with Mystical Experiences in a Dose-Dependent Manner Adults recruited from the MAPS website and newsletter, most reporting use of various... | 2012 | Cross-sectional survey | n = 337 |