The Index of Cannabis Equivalence (ICE): A User-Centered Approach to Standardization of Cannabis Dose-Response

J Psychoactive Drugs. 2025 Jan 9:1-6. doi: 10.1080/02791072.2025.2449932. Online ahead of print.

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.

Keywords: Cannabis; THC; cannabinoid content; intoxication; measurement; standard dose.