Cannabis will remain a banned substance in sport after a review by the World Anti-Doping Agency (Wada).
American sprinter Sha’Carri Richardson was ruled out of the Tokyo Olympics after receiving a one-month ban for using the drug last year.
Wada agreed to review the cannabis ban after requests from “stakeholders”.
But it decided on Friday at a meeting of its executive committee to maintain the ban because the use of the drug “violated the spirit of sport”.
The ban for recreational drug use by athletes who test positive out of competition was reduced from two years to one to three months last year.
“Wada is aware of the diversity of opinions and perceptions related to this substance around the world, and even within certain countries,” director general Olivier Niggli said.
“Wada plans to continue research in this area in relation with [its] potential performance enhancing effects, its impact on the health of athletes and also in relation to perceptions of cannabis from athletes, experts and others around the world.”
In the UK cannabis is a class B drug and possession carries a penalty of up to five years in prison and an unlimited fine.
The organisation also announced that the painkiller tramadol is to be added to the list of banned substances for athletes in competition from 2024.
“Tramadol abuse, with its dose-dependent risks of physical dependence, opiate addiction and overdoses in the general population, is of concern and has led to it being a controlled drug in many countries,” Wada said in a news release.
Former England goalkeeper Chris Kirkland said in July he had been driven to the point of suicide by his addiction to, and abuse of, tramadol after using the opioid to treat back injuries.